C 1 55/ /3 ." A/fi) F5 aRC 44b 446 ii .Ay •^ SW£ ^. • i 3 :382 % :- IMOAA Technical Report NMFS Circular 446 / ¥ \ c ^|^ ^TES O* * / Marine Flora and Fauna of the Northeastern United States. Lichens (Ascomycetes) of the Intertidal Region Ronald M. Taylor August 1982 U.S. DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Marine Fisheries Service NOAA TECHNICAL REPORTS National Marine Fisheries Service, Circulars The major responsibilities of the National Marine Fisheries Service (NMFS) are to monitor and assess the abundance and geographic distribution of fishery resources, to understand and predict fluctuations in the quantity and distribution of these resources, and to establish levels for optimum use of the resources. NMFS is also charged with the development and implementation of policies for managing national fishing grounds, development and enforcement of domestic fisheries regulations, surveillance of foreign fishing off United States coastal waters, and the development and enforcement of international fishery agreements and policies. NMFS also assists the fishing industry through marketing service and economic analysis programs, and mortgage insurance and vessel construc- tion subsidies. It collects, analyzes, and publishes statistics on various phases of the industry. The NOAA Technical Report NMFS Circular series continues a series that has been in existence since 1941. The Circulars are technical publications of general interest intended to aid conservation and management. Publications that review in considerable detail and at a high technical level certain broad areas of research appear in this series. Technical papers originating in economics studies and from management investigations appear in the Circular series. NOAA Technical Report NMFS Circulars are available free in limited numbers to governmental agencies, both Federal and State. They are also available in exchange for other scientific and technical publications in the marine sciences. Individual copies may be obtained (unless otherwise noted) from D822, User Services Branch. Environmental Science Information Center, NOAA, Rockville, MD 20852. Recent Circulars are: 418. Annotated bibliography of four Atlantic scombrids: Scomberomorus brasil- iensis, S. cavalla, S. maculatus, and S. regalis, by Charles S. Manooch III, Eugene L. Nakamura, and Ann Bowman Hall. December 1978, iii + 166 p. 419. Marine flora and fauna of the northeastern United States. Protozoa: Sarco- dina: Amoebae, by Eugene C. Bovee and Thomas K. Sawyer. January 1979, iii +56 p., 77 figs. For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. Stock No. 003-017-00433-3. 420. Preliminary keys to otoliths of some adult fishes of the Gulf of Alaska. Bering Sea, and Beaufort Sea, by James E. Morrow. February 1979, iii+32p..9pl. 421 . Larval development of shallow water barnacles of the Carolinas (Cirripedia: Thoracica) with keys to naupliar stages, by William H. Lang. February 1979, iv+39 p., 36 figs., 17 tables. 422. A revision of the catsharks, family Scyliorhinidae. by Stewart Springer. April 1979, v + 142 p.. 97 figs. For sale by the Superintendent of Documents, U.S. Gov- ernment Printing Office. Washington, D.C. 20402, Stock No. 003-020-00147-5. 423. Marine flora and fauna of the northeastern United States. Crustacea: Cuma- cea, by Les Watling. April 1979. iii +23 p., 35 figs. For sale by the Superintendent of Documents, U.S. Government Printing Office. Washington, D.C. 20402. Stock No. 003-017-00446-5. 424. Guide to the leptocephali (Elopiformes, Anguilliformes, and Notacanthi- formes), by David G. Smith. July 1979, iv +39 p., 54 figs. 425. Marine flora and fauna of the northeastern United States. Arthropoda: Cirri- pedia, by Victor A. Zullo. April 1979, iii +29 p., 40 figs. For sale by the Superin- tendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402, Stock No. 003-017-00453-8. 426. Synopsis of biological data on the rock crab. Cancer irroratus Say, by Thomas E. Bigford. May 1979. v+26p.. 11 figs., 21 tables. 427. Ocean variability in the U.S. Fishery Conservation Zone, 1976, by Julien R. Goulet, Jr., and Elizabeth D. Haynes, editors. July 1979, iii+362 p. 428. Morphological comparisons of North American sea bass larvae (Pisces: Ser- ranidae). by Arthur W. Kendall. Jr. August 1979, iv+50p.. 43 figs., 9 tables. 429. Synopsis of biological data on tunas of the genus Euthynnus, by Howard O. Yoshida. October 1979, iv +57 p., 40 figs., 30 tables. 430. Guide to identification of some sculpin (Cottidae) larvae from marine and brackish waters off Oregon and adjacent areas in the northeast Pacific, by Sally L. Richardson and Betsy B. Washington. January 1980, iv +56 p.. 32 figs., 45 tables. 43 1 . Guide to some trawl-caught marine fishes from Maine to Cape Hatteras, North Carolina, by Donald D. Flescher. March 1980, iii+34 p. 432. Synopsis of biological data on bonitos of the genus Sarda. by Howard O. Yoshida. May 1980, iv+50p..43 figs., 26 tables. 433. Synopsis of biological data on striped bass, Morone saxatilis (Walbaum). by Eileen M. Setzler. Walter R. Boynton, Kathryn V. Wood, Henry H. Zion, Lawrence Lubbers, Nancy K. Mountford, Phyllis Frere, Luther Tucker, and Joseph A. Mihursky. June 1980, v+69p., 9 figs., 24 tables. 434. Osteology, phylogeny, and higher classification of the fishes of the Order Plectognathi (Tetraodontiformes). by James C. Tyler. October 1980, xi+422 p., 326 figs.. 3 tables. 435. Field guide to fishes commonly taken in longline operations in the western North Atlantic Ocean, by Joseph L. Russo. January 1981, iii +51 p., 58 figs. 436. Synopsis of biological data on frigate tuna, Auxis lhazard, and bullet tuna, A. rochei, by Richard N. Uchida. January 1981 , iv +63 p., 52 figs., 27 tables. 437. Fishery publication index, 1975-79. by Lee C. Thorson. May 1981, iii + I 17 P- 438. Marine flora and fauna of the northeastern United States. Scleractinia, by Stephen D. Cairns. July 1981 , iii + 15 p.. 16 figs., 2 tables. 439. Marine flora and fauna of the northeastern United States. Protozoa: Sarco- dina: benthic Foraminifera. by Ruth Todd and Doris Low. June 1981 , iii +51 p., 23 figs. 440. Marine flora and fauna of the northeastern United States. Turbellaria: Acoela and Nemertodermatida, by Louise F Bush. July 1981 . iii +71 p., 184 figs. 441 . Synopsis of the biology of the swordfish. Xiphias gladius Linnaeus, by B. J. Palko. G. L. Beardsley, and W. J. Richards. November 1981 , iv +21 p., 12 figs., 5 tables. 442. Proceedings of the Sixth U.S.— Japan Meeting on Aquaculture, Santa Bar- bara, California, August 27-28, 1977, by Carl J. Sindermann (editor). March 1982, iii +66 p. NOAA Technical Report NMFS Circular 446 rfPgggW Marine Flora and Fauna of the Northeastern United States. Lichens (Ascomycetes) of the Intertidal Region Ronald M. Taylor August 1982 C O O o o a o U.S. DEPARTMENT OF COMMERCE Malcolm Baldridge, Secretary National Oceanic and Atmospheric Administration John V. Byrne, Administrator National Marine Fisheries Service William G. Gordon, Assistant Administrator for Fisheries FOREWORD This NMFS Circular is part of the subseries "Marine Flora and Fauna of the Northeastern United States," which consists of original, illustrated, modern manuals on the identification, classification, and general biology of the estuarine and coastal marine plants and animals of the northeastern United States. The manuals are published at irregular intervals on as many taxa of the region as there are specialists avail- able to collaborate in their preparation. Geographic coverage of the "Marine Flora and Fauna of the Northeastern United States" is planned to include organisms from the headwaters of estuaries seaward to approximately the 200 m depth on the con- tinental shelf from Maine to Virginia, but may vary somewhat with each major taxon and the interests of collaborators. Whenever possible representative specimens dealt with in the manuals are deposited in the reference collections of major museums of the region. The "Marine Flora and Fauna of the Northeastern United States" is being prepared in collaboration with systematic specialists in the United States and abroad. Each manual is based primarily on recent and ongoing revisionary systematic research and a fresh examinatin of the plants and animals. Each major taxon, treated in a separate manual, includes an introduction, illustrated glossary, uniform originally illus- trated keys, annotated checklist with information when available on distribution, habitat, life history, and related biology, references to the major literature of the group, and a systematic index. These manuals are intended for use by biology students, biologists, biological oceanographers, informed laymen, and others wishing to identify coastal organisms for this region. Often they can serve as guides to additional information about species or groups. The manuals are an outgrowth of the widely used "Keys to Marine Invertebrates of the Woods Hole Region," edited by R. I. Smith in 1964, and produced underthe auspices of the Systematics Ecology Pro- gram, Marine Biological Laboratory, Woods Hole, Mass. After a sufficient number of manuals of related taxonomic groups have been published, the manuals will be revised, grouped, and issued as special vol- umes, which will consist of compilations for phyla or groups of phyla. CONTENTS Introduction ' Methods of collection and studying 1 Ecology 2 Glossary 4 Illustrated key to species ° Annotated list of species ^ Selected bibliography 22 Systematic index 24 Acknowledgments L J Coordinating Editors comments 26 The National Marine Fisheries Service (NMFS) does not approve, rec- ommend or endorse any proprietary product or proprietary material mentioned in this publication. No reference shall be made to NMFS, or to this publication furnished by NMFS, in any advertising or sales pro- motion which would indicate or imply that NMFS approves, recommends or endorses any proprietary product or proprietary material mentioned herein, or which has as its purpose an intent to cause directly or indirectly the advertised product to be used or purchased because of this NMFS publication. Marine Flora and Fauna of the Northeastern United States. Lichens (Ascomycetes) of the Intertidal Region RONALD M. TAYLOR' ABSTRACT This manual treats the lichens found in the intertidal region from New Jersey to Newfoundland. Methods of collection, preparation, and study are briefly treated. Twenty-two species are covered, both in an illustrated key and an alphabetical listing, with brief descriptions and notes on ecology and distribution. A glossary of terms is included. INTRODUCTION METHODS OF COLLECTION AND STUDYING 6 a a. c> The content and style of this paper are intended to encourage and serve all who might wish to study the lichens of the fascinating and complex marine littoral environment. It is evident from the lit- erature and from inquiries directed to the author that the marine lichen flora presents an interesting enigma to biologists of diverse disciplines. It is hoped that this paper will help them in studying, recognizing, and accurately reporting the lichens of the littoral zone. A lichen is not "a plant" but rather a life or growth form com- prised of two kinds of plants, a fungus and an alga, growing together in a symbiotic relationship. Although botanists differ as to the exact nature of the symbiotic relationship, each member of the relationship seems to benefit from the other. In reality, there are probably different kinds of relationships in different lichens. Most lichens are fungus dominated, i.e., the shape and most of the mass of the lichen is derived from the fungus. All the marine lichens treated in this manual, except for the genus Lichina, are fungus dominated and the fungus is an Ascomycete. Marine lichens occur in three growth forms: fruticose, foliose, and crustose. Fruticose forms are usually upright or pendant in rela- tionship to the substrate; they stand out away from the substrate. Lichina, the only genus of fruticose lichens in the littoral region grows in a shrublike form. Foliose forms, as the name implies, have a leafy appearance, often in rosette form, and may be removed from the substrate. The only genus of foliose lichens in the littoral region is Xanthoria. Crustose forms often appear as discolored areas on rocks and are usually destroyed if one attempts to remove them from the substrate. They may be shiny or dull, black, green, or brown. Most marine lichens are crustose and grow on rocks; one species, Arthopyrenia halodytes, grows on barnacles. Lichens may be found in a continuous range of habitats, from low tide to mountain tops. The species included in this manual are those found in the intertidal zone plus the normal spray zone but not what is often called the "storm spray zone." Some of the lichens in this manual are obligate marine lichens, i.e.. they grow only where they are struck directly by saltwater. Others are facultative, being found also in areas remote from the sea. My criterion for including a facultative lichen is its occurrence with, or at the same height on the shore as, an obligate marine species. 'Science Department. Lansing Community College, Lansing. MI 48914. Marine lichens inhabit rocks or the barnacles attached to them. Most littoral lichens are crustose and cannot be removed from the rocks without being destroyed. They must be collected along with a piece of the rock substrate, using rock chisels and a 3-lb hammer. Ideally one should strive to collect specimens on pieces of rock small enough to fit well into 4" x 6" herbarium packets. This will not always be possible because the lichen may grow on an irregular piece of rock that does not break easily. Further preparation can be done in the laboratory, but it is usually easier to reduce the size of a rock in the field. Once the specimen is removed it must be placed in a suitable container. Paper bags are quite satisfactory if the bag is strong. Unfortunately, the specimens are often wet, and the wet bag may need to be placed in another bag. Plastic or other waterproof bags are not desirable since they retard drying and promote molding. If a waterproof bag is used in the field, the specimen should be transfer- red to a paper bag and air dried within a day of collection. A rock saw would seem to provide a fairly ideal solution to the problem of shaping rocks for herbarium packets in the laboratory. However, the use of a rock saw requires a liquid coolant to protect the blade. In preparing lichen specimens, water should be used rather than the oil employed in lapidary work. This works well with nonlittoral specimens, but with littoral lichens the soaking that results from the water coolant and the additional water required to rinse the specimen causes excessive reticulation that is detrimental to future study. Hydraulic devices are available which break rocks by applying pressure to chisellike jaws. These produce fractures in the rocks that are not as neat or predictable as the cut of a saw but they do avoid reticulation and are quite satisfactory. After sizing, the rocks should be glued to cards of suitable size. This prevents abrasion of the specimens and degradation of the rock. Also, it provides a way to permanently identify the rock frag- ments examined for the lichen in question. Many of the diagnostic characteristics of littoral lichens are readily observed with a dissecting microscope at a magnification of 20 power. Bright illumination is important because of the dark color of many thalli, especially in the genus Verrucaria. Thalli should be observed in both wet and dry conditions. Water added to the thallus sparingly to avoid unnatural reticulation often increases its trans- parency, thus revealing subsurface patterns. Sections of fruiting structures may be made by hand with a razor blade. The small size of the perithecia of many species of Ver- rucaria are difficult but not impossible to section. A double edged razor blade, broken lengthwise, is most suitable. Microtome sections are complicated by the thin crustose nature of the thalli and their adherence to the rock substrate. Furthermore the involucrella of pyrenocarpous lichens are hard and brittle and do not respond well to the usual paraffin imbedding techniques. Two techniques employing a freezing microtome are satisfac- tory. One technique involves pouring a shallow layer of agar in a small container. The perithecium is moistened several times with water containing a small amount of wetting agent, such as alcohol. The perithecium and the subtending and surrounding thallus are then scooped from the rock with a razor blade, taking care to lift the entire perithecium from the rock. Faulty diagnosis will result if the base of the perthecium is left on the rock. The thallus and perithe- cium are then transferred to the surface of the agar. A drop of melted agar placed over the lichen material embeds it between the two lay- ers of agar. A cube cut from the agar is then placed on the freezing microtome so that the thallus is perpendicular to the blade and the vertical axis of the perithecium is parallel to the blade. The material is then frozen and sectioned. The other technique involves commercially available synthetic plastic materials intended for embedding frozen sections. A mound is built up on the microtome s object disc and frozen. A vertical face is cut facing and perpendicular to the blade. The lichen material to be cut is prepared as before and then pressed firmly against the embedding material. The pressure melts the plastic and when the pressure is released the plastic and embedding lichen fuse and freeze solid. Both techniques have the disadvantage of leaving visible resi- dues on the slide surrounding the sections. This is a problem only if the slide is to be photographed. Some species of lichens give a color reaction to potassium hydroxide. A drop of 10% solution is applied with a dropping pipette or capillary tube, directly to the cortex, or to medulla exposed by fragmentation or an incision. Santesson (1939) described a number of environmentally induced morphological variations in littoral lichens in general and described in detail the variations of certain selected species. Both Weber (1962) and Santesson (1939) have emphasized the impor- tance of understanding the range of variation induced by the environment. The author has traced variations of single thalli from continu- ous to areolate and from smooth to ridged. The author has also observed variations of perithecia from sunken to prominently raised on a single thallus. Even the darkness of the lower side of the excipulum (inner lining of perithecium) is quite variable within a single species. Shade modification is well known and predictable among littoral lichens. Shade causes lighter pigmentation and reduction in size and number of juga (black pegs, lumps, or ridges protruding from the surface). Some species that are distinct in appearance when growing in good illumination appear much less distinct when growing in the shade. The distinguishing features of a species are frequently reduced by the shade modification. As a result there is considerable taxonomic confusion among the shade modifications of Verrucaria sthatula, V. ditmarsica, and, to a lesser degree, V. erichsenii. Too much stress can be placed on perithecium size. Variations of perithecium size on a single thallus beyond the range accepted in some taxonomic keys have been observed. Thus the taxonomic character "perithecia slightly smaller (or larger) than ..." should be regarded with suspicion. If one s study is restricted to a few specimens, it is easy to see dichotomy among the species examined. As the number of speci- mens increases, the kinds and degrees of variations also increase and extreme forms are bridged by lesser variations. Since the litto- ral environment is one of great physical contrasts and many micro- habitats, it is not suprising that considerable taxonomically confusing variations in the lichens have resulted. ECOLOGY Between low and high tide marks the rocks of the shore are largely covered by macroaglae such as Fucus sp. Among the hold- fasts of such algae, the marine lichens compete for space with bar- nacles, Bryozoa, and such algae as Hildenbrantia and Lithothamnia. The lichen Arthopyrenia halodytes often occupies the shells of the barnacles with which the other lichens compete. Perithecia, the cone-like fruiting structures of marine lichens, are often seen protruding through the thalli of HUdenbrantia or Litho- thamnia which have overgrown them. Such competition with the lichen Verrucaria mucosa has mixed results; either the lichen or the alga may establish itself on top. Only the lichen genera Arthopyre- nia, Stigmidium, and Verrucaria are found throughout this zone of the shore. The Verrucaria species maura and ceuthocarpa do not extend very far down into this zone. From the high tide mark upward for about 0.5 m is the barnacle belt. The barnacles are so successful in the competition for space that only their shells are available as a substrate for lichens. The lichen Arthopyrenia halodytes is found here in pits dissolved into the barnacle shells. Extending upward from the barnacle belt is the black belt pop- ulated by various species of Verrucaria in competition with blue- green algae, especially of the genus Calothrix. Investigators in northern Europe find a well defined orange belt above the black belt and a white "Ramalina belt" above that. In northeastern North America the orange belt is intermittent or absent and the "Ramalina belt" is entirely absent. The orange belt, where present, is comprised of members of the genera Caloplaca and Xanthoria. Lichina confinis, a black fruticose lichen, may be found in this belt or extending down to the black belt. Various other lichens may extend into the orange belt but in the few and incom- plete orange belts encountered in northeastern North America by the author, only Lecanora grantii, a gray crustose lichen with cup- like fruiting bodies, was found. Nothing above the orange belt was considered in this study because it is the highest zone to contain obligate marine lichens. The lichen flora collected at the northern end of the study range was comprised of 22 species. At the southern end of the range the lichen flora was reduced to two species. In an attempt to explain the distribution in terms of environmental cause, a multiple regres- sion analysis was used to assess the impact of environmental factors on the success of individual species and on the general diversity of species. The environmental factors whose individual and interac- tive effects were computed are: salinity, air and water temperatures, solar insolation, and tidal range. No simple answers emerged either for the success of any species or for general diversity. However, by tallying the number of times that each environmental factor was involved as one of the most important influences, the following fre- quencies resulted: salinity. 21; insolation, 15; air temperature, 12; tidal range, 7; and water temperature, 2. Where sufficient collections were made to provide adequate data, vertical distributions of the various marine lichens were graphed (Figs. 1-8). In these graphs the extent above mean high -i 10m -, 10m r- A MHW 4hrs 8hrs 12hrs 16hrs \- 20hrs - 24hrs 502 -I Is Figure 1.— Vertical distribution of Arthopyrenia halodytes. Figure 4.— Vertical distribution of Verrucaria erichsenii. 10m MHW 4hrs 8hrs 12hrs 16hrs 20hrs 24hrs Figure 2.— Vertical distribution of Verrucaria degelii. Figure 5.— Vertical distribution of Verrucaria maura. 10m ,- > Figure 3.— Vertical distribution of Verrucaria ditmarsica. Figure 6. — Vertical distribution of Verrucaria microspora. 5' : - 5m - 50 ■J^JJ^T 1 1 ! 1 Qhrs I 12hrs 16hrs 20hrs l 24hrs -i 1 Oin _ HHW 4hrs 8hrs 12hrs 16hrs 20hrs 24hrs Figure 7.— Vertical distribution of Verrucaria mucosa. Figure 8.— Vertical distribution of Verrucaria striatula. tide is given in meters. Due to the great variation in the distance between mean low tide and mean high tide (ca. 1 to 10 m), the dis- tance below high tide is given in hours of submergence. Each inter- val on the X-axis represents 10% of the total collections of that species by the author. In each figure the graph on the right repre- sents the vertical distribution on exposed shores and the graph on the left represents the vertical distribution on sheltered shores. GLOSSARY The use of lichenological terminology in this publication has been reduced to a minimum. Several terms are illustrated as well as defined. Apical At the tip or apex (Fig. 9). Apothecium (pi. Apothecia) Disc, saucer, or cup shaped fruit- ing body (Fig. 9). Areolate Broken by clefts into small, usually angular and irreg- ular patches (areoles). Areole (pi. Areoles) Area of a thallus divided from the rest of the thallus by fissures (Fig. 10). Arete (pi. Aretes) Sharp peak elevated above a ridge. Ascocarp (pi. Ascocarps) An Ascomycete fruiting body giving rise to and containing asci and ascospores (Figs. 9. 10). Ascus (pi. Asci) A sack-like structure within which ascospores are formed and contained in the ascocarp (Fig. 10). Carbonaceous Made up largely of carbon deposits. lamina! ■phycobiont medul la thall ine margin upper cortex lower cortex ascus- Lparaphyses- • hymen i urn Figure 9.— Composite foliose lichen with apothecia. Citrine Lemon yellow color. Conidiwn (pi. Conidia) Asexual reproductive spores of Asco- mycete. Continuous Thallus unbroken by gaps or fissures. Cortex (pi . Cortices or Cortexes) The compact outermost fun- gal layer of a lichen thallus (Figs. 9, 10). Craterous Having a depression resembling the crater of a vol- cano. Crenulate Having small rounded lobes. Crustose A type of thallus which usually adheres tightly to the substrate and cannot be removed from it without destruction of the thallus; lacks a lower cortex and rhizines (Fig. 10). Cusp (pi. Cusps) Crescent shaped mound. Dendritic Having a pattern resembling the branching of a tree limb. Dispersed Scattered . Endolithic Growing within the rock substrate. Epithecium (pi. Epithecia) Covering of the hymenium. Evaginate To protrude as if a pocket turned inside-out. Excipulum (pi. Excipula) As used here, the inner wall of a perithecium. Foliose A type of thallus, leaflike or lobed, often with rhizines or hairlike processes on lower surface, usually with lower cortex, algal layer limited to upper side (Fig. 9). Fruticose A type of thallus that is shrublike, stalked, or pen- dant with the algal layer usually on all sides. Fusiform Narrowed both ways from a swollen middle. Glabrous Having a smooth even surface. Globose Spherical. Holdfast (pi. Holdfasts) The basal portion of an algal thallus attaching it to the substrate. Hyaline Colorless. Hymenium (pi. Hymenia) The layer of the ascocarp containing the asci and usually paraphyses (Fig. 9). Hypothallus (pi. Hypothalli) A marginal outgrowth of hyphae from the thallus of a crustose lichen (Fig. 10). Immersed Sunken mostly or entirely below the surface of the thallus. Impressed Indented. Involucrellum (pi. Involucrella) The usually black and carbo- naceous covering of a perithecium (Fig. 10). Isidium (pi. Isidia) Small cylindrical, coralloid, or globose outgrowths of the thallus serving as vegetative disseminules. They are covered with cortex and contain both fungal and algal compo- nents (Fig. 9). Isthmus (pi. Isthmuses) A narrow passage. Jugum (pi. Juga) Protrusions of carbonaceous material extend- ing at least partly above the thallus surface as ridges, pegs, or irreg- ular lumps (Fig. 10). Lamina! On the flat surface of the thallus (usually upper) (Fig. 9). Lenticular An area, pointed at each end, inclosed by two inter- secting convex curves. Littoral lichen Growing between the tides. The term is extended herein to include those struck by saltwater due to wave action and is used interchangeably with the term "marine." Locule (pi. Locules) Chamber or cavity. Medulla (pi. Medullae) An area of loosely packed hyphae internal to the thallus and its projections such as podetia, isidia, etc. (Figs. 9, 10). Morphotype (pi. Morphotypes) A thallus of a given species having a different appearance than other members of the species. Necral Occurring after death. Necral reticulation A network of cracks caused by treatment and/or storage after collection. Nodular convex Like a small rounded lump. Oblong ellipsoid In the form of an elongated circle; more elon- gated than the typical elipse. Oblong ovoid In the form of an elongated oval . Olivaceous Having a color similar to that of a green olive. Orbicular Spherical or nearly so. Ostiole (pi. Ostioles) The apical opening of a perithecium (Fig. 10). Paraphysis (pi. Paraphyses) Sterile hyphae intermingled with asci in the hymenium of an ascocarp (Figs. 9, 10). Parasymbiont (pi. Parasymbionts) An organism living in harmless association with another without mutual benefit. Pendant Dangling. Perithecoid In the shape of a perithecium. perithecium hypotha areol lucre! 1 um pegs jugum ortex paraphyses L medulla Figure 10.— Composite crustose lichen with perithecia. Perithecium (pi. Perithecia) A flask-shaped ascocarp enclosed except for the apical pore (ostiole). It is usually more or less sunken into the thallus (Fig. 10). Phxcobiont (pi. Phycobionts) The algal member of the lichen symbiosis (Figs. 9, 10). Pseudoseptum (pi. Pseudosepta) Appearing to be an internal wall but not composed of the same material forming the cell wall. Pycnidium (pi. Pycnidia) Small flask-shaped to globular struc- tures resembling perithecia but containing conidia instead of asci and ascospores. Pyrencocarpous Having perithecia. Pyrenolichen (pi. Pyrenolichens) Lichen having perithecia (Fig. 10). Reniform Kidney shaped. Reticulation A netlike appearance. Rimose Having minute cracks, usually referring to a form of areolation. Saxicolous Growing on a rock or rock-like substrate. Sessile Not supported by a stalk. Simple Describing a spore having a single, undivided cavity. Sorediate Having soredia on the thallus. Soredium (pi. Soredia) A means of vegetative reproduction of the lichen consisting of masses of hyphae and their associated algae rupturing through and not covered by or containing cortex (Fig. 9). Spray zone (pi. zones) That area above high tide that is struck by drops of seawater resulting from the impact of waves on the rocky shore under nonstorm conditions. Storm spray zone (pi. zones) That area, above the usual spray zone, that is sprayed with seawater only during a storm. Subconvex Barely curved outward. Subejfuse Having boundaries that are poorly distinguished. Submerged Sunken entirely or mostly below the upper surface of the thallus. Submoniliform Having constrictions at intervals giving an appearance nearly like a string of beads but not so pronounced. Tlialline margin (pi. margins) Apothecial rim having the same composition as the thallus (Fig. 9). Tliallus (pi. Tlialli) The lichen body containing both algal and fungal components. Tuberculate Having a warty appearance. ILLUSTRATED KEY TO SPECIES The key is based primarily on characteristics that can be observed with a dissecting microscope at 20 x magnification; in some cases observation of spores with a compound microscope may be required. The vertical sections of perithecia of Verrucaria species illustrated in the key are typical sections. Because of the extreme degree of variation of species of marine lichens (especially of Verrucaria), identification of species from the key alone should be regarded as tentative until the more detailed description in the Annotated List of Species is read. Five species from the Canadian Maritime Provinces are included even though at present they are not known from the eastern United States. At least one species, Verrucaria maura, has not been collected in the eastern United States recently but the author has seen specimens collected from the area over 50 yr ago. 1 Thallus foliose (Fig. 9); always orange and KOH + purple 2 1 Thallus crustose (Fig. 10) only in a few species orange and KOH + purple 4 1 Thallus erect, fruticose, composed primarily of algal (Calothri.x) filaments; ascocarp perithecioid (Fig. 11) Lichina confinis Figure 11.— Lichina confinis. Scale is 0.1 mm. 2 (7) Thallus with soredia mostly apical (Fig. 12); thallus lobes finely divided (0.2-0.5 mm wide) Xanthoria candelaria Figure 12.— Thallus of Xanthoria candelaria. Scale is 1 mm. 2 (1) Thallus not sorediate, lobes wider than 0.5 mm 3 3 (2) Lobes flattened and 1 mm or more broad (Fig. 13) Xanthoria parietina Figure 13.— Thallus of Xanthoria parietina. Scale is 1 mm. 3 (2) Lobes nodular-convex, lobes less than 1 mm wide (Fig. 14) Xanthoria elegans Figure 14.— Thallus of Xanthoria elegans. Scale is 1 mm. 4 (7) Ascocarp an apothecium (Fig. 9); thallus light (shades of white, gray, or yellow orange) 5 4 (7) Ascocarp a perithecium (Fig. 10); occasionally more or less immersed with only ostiole showing; thallus dark (shades of green, brown, or black) or apparently absent 9 5 (4) Thallus whitish to gray, KOH + yellow; spores colorless, one-celled (Fig. 15), 11-18 X 6-8. 5^m Lecanora grantii Figure 15.— One-celled spore. Scale is 10>m. 5 (4) Thallus yellow orange, KOH + purple; spores colorless, polarilocular (Fig. 16) 6 Figure 16. — Polarilocular spore. Scale is 6 (5) Thallus covered with globose isidia (Fig. 17); spores 9-14 X 4-6/im Caloplaca verruculifera Figure 17.— Thallus of Caloplaca verruculifera. Scale is 10 mm. 6 (5) Thallus without isidia 7 7 (6) Thallus forming circular patches with radiating lobes (Fig. 18); spores 10-15 x 5-7/tm Caloplaca scopularis Figure 18.— Thallus of Caloplaca scopularis. Scale is 10 mm. 7 (6) Thallus irregular, composed of scattered lobes or numerous granules . 8 (7) Thallus citrine of granules 1-3 mm diameter (Fig. 19), spores 10-18 x 5-8^m Caloplaca microthallina Figure 19.— Thallus of Caloplaca microthallina. Scale is 10 mm. £? a ^ 03 8 (7) Thallus orange yellow, marginal lobules subconvex oriented in radiating manner; spores 10-14 x 5-7/tm (Fig. 20) Caloplaca marina Figure 20.— Thallus of Caloplaca marina. Scale is 1 mm. 9 (4) Spores one-celled 11 9 (4) Spores more than one-celled 10 10 (9) Growing on thallus of Verrucariae; paraphyses gelatinizing, spores 10-15 x 3.5-5^m with 4 locules and distinct cen- tral septum (Fig. 21) Stigmidium marinum Figure 21.— Spore of Stigmidium marinum. Scale is 10^m. 10 (9) On barnacles or rock; thallus scant to evidently lacking; paraphyses persistent, spores 9-20 x A-lfim with two locules (Fig. 22) Arthopyrenia halodytes Figure 22. — Spore of Arthopyrenia halodytes. Scale is 10>m. 1 1 (9) Thallus with pegs and/or ridges present (Fig. 23) 16 Figure 23.— a. Thallus with pegs. b. Thallus with ridges. Scale is 1 mm. a • • b 1 1 (9) Thallus smooth; pegs and ridges lacking 12 12 (77) Thallus areolate (divided into fields by fissures, Fig. 24) 15 Figure 24.— Areolate thallus. Scale is 1 mm. I I 12 (77) Thallus continuous or discontinuous but not areolate (Fig. 25) 13 J *r Figure 25.— a. Continuous thallus. b. Discontinuous thallus. Scale is 1 mm. I 1 13 (72) Perithecia elevated, often shiny, dome-shaped to hemispherical or sometimes pointed (Fig. 26) 14 Figure 26.— Thallus with elevated perithecia. Scale is 1 mm. 1 1 13 (12) Perithecia submerged to slightly elevated (Fig. 27); spores 8-11 x 4-5 ^tm; thallus thick, green to greenish-black Verrucaria mucosa Figure 27.— Thallus with submerged to slightly elevated perithecia. Scale is 1 mm. » 1 14 (13) Spores 6- 1 1 x 3-5/im Verrucaria microspora 14 (13) Spores 18-22 x 8-9/wn Verrucaria silicicnla 15 (12) Areoles light brown on dark brown prothallus (Fig. 28); perithecia brown; spores thick walled (11.5) 15-23 (27) x (4) 6-8( 14)/xm Verrucaria internigrescens ««JpL„.. Figure 28.— a. Vertical section of "'?v, l ;. k ■'}.:■- perithecium. Scale is 0.1 mm. b. i a Thallus of Verrucaria internigres- cens. Scale is 1 mm. D 15 (12) Prothallus not evident; thallus prominently fissured; perithecia brown or black; spores thin-walled, 9-12 x 5-6/*m (Fig. 29) Verrucaria ceuthocarpa rcn Figure 29.— a. Vertical section of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria ceuthocarpa. Scale is 0.1 mm. 10 16 (77) Thallus areolate (thallus divided into fields by fissures, Fig. 30) 17 Figure 30.— Areolate thallus. Scale is 1 mm. 16 (77) Thallus not areolate 20 17 (16) Areoles bordered by raised juga (Fig. 31) If Figure 31. — Areoles bordered by juga. Scale is 0.1 mm. 17 (76) Areoles not bordered by juga (Fig. 32) 19 Figure 32. — Areoles without juga. Scale is 0.1 mm. 11 18 (17) Perithecia usually immersed, ostiole border frequently raised, spores 9-12 x 5-6/xm; juga rarely limited to borders of areoles, usually scattered within areoles (Fig. 33); thallus more translucent wet than dry Verrucaria degelii Figure 33.— a. Vertical section of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria degelii. Scale is 1 mm. 18 (J 7) Perithecia elevated, often craterous, juga forming a reticulate pattern (Fig. 34); thallus opaque dry, translucent wet Verrucaria amphibia Figure 34.— a. Vertical section of perithecium. Scale is 1 mm. b. Thallus of Ver- rucaria amphibia. (Specimen illustrated is thicker and stored longer than that in Fig. 39b.) Scale is 1 mm. 19 (1 7) Juga appearing as pegs protruding from thallus and also to some extent on perithecia; thallus rimose-areolate, usually blackish-brown and opaque (wet or dry); perithecia often large, 0.3-0.7 mm diameter, immersed or elevated, gently sloped to rising abruptly, sometimes depressed on top (Fig. 35); spores 10-20 x 7-10/xm Verrucaria maura Figure 35.— a. Vertical sections of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria maura. Scale is 1 mm. 12 19 (7 7) Juga raised or immersed, appearing as usually irregular and often branched ridges often merging with or continuing over perithecia, if immersed appearing as black spots when wet; thallus blackish-brown, becoming brown to amber and translucent when wet; perithecia spreading and irregular at base, up to 0.3 mm diameter (Fig. 36); spores 8-9 X 4.5-7/tm Verrucaria erichsenii Figure 36.— a. Vertical section of perithe- cium. Scale is 0.1 mm. b. Thallus of Verruca- ria erichsenii. Scale is 1 mm. 20 (16) Perithecia immersed, spores 9-12 x 5-6/*m; juga appearing as long sharp black ridges on borders of thallus, some- times extending across thallus, fissures occasionally develop along juga and simulate areolation; thallus usually green to cream colored (Fig. 37) Verrucaria degelii Figure 37.— a. Vertical section of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria degelii Scale is 1 mm. 20 (16) Perithecia raised and prominent (Fig. 38) 21 Figure 38.— Thallus with prominent raised perithecia. 21 (20) Juga inclosing lenticular areas giving appearance of ripples on water, continuing on perithecium to form reticular pattern. Perithecium elevated, often craterous (Fig. 39); spores 9-20 x 4-7. 5^m Verrucaria amphibia Figure 39.— a. Vertical section of perithecium. Scale is 1 mm. b. Thallus of Verrucaria amphibia. (Thai us thinner than Fig. 34b. Cracks developed in storage.) Scale is 1 mm. 21 (20) Juga scattered, not inclosing lenticular areas 22 13 22 (21) Juga appearing as pegs to usually short ridges, usually straight but sometimes crescent shaped, sometimes coa- lescing with perithecium at base; thallus usually dark olive green but lighter and with fewer juga in shade; peri- thecia hemispherical, often shiny (Fig. 40); spores 6-1 1 x 3-5/xm Verrucaria ditmarsica Figure 40. —a. Vertical section of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria ditmarsica. Scale is 1 mm. 22 (21) Juga broader, irregular, and sometimes branched (Fig. 41) .23 Figure 41. —Thallus with broad, sometimes branched juga. Scale is 1 mm. 23 (22) Juga conspicuous, highly irregular, frequently branched, raised or immersed and appearing as conspicuous black spots in wet thallus, often merged with perithecia; wet thallus usually brown to amber and translucent (Fig. 42); perithecia up to 0.3 mm diameter, spores 8-9 x 4.5-7/xm Verrucaria erichsenii Figure 42.— a. Vertical section of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria erichsenii. Scale is 1 mm. 14 23 (22) Juga prominent, black, and shiny, much thicker than in V, erichsenii, frequently broadened into thick irregular plates, especially at thallus margin; thallus usually grass green but darker in the sun and depigments rapidly in shade or in storage; perithecia typically hemispherical to globular with flattened tops but may become quite irregular, angular, or dissected (Fig. 43); spores 8-10 x 4-6/im Verrucaria striatula Figure 43.— a. Vertical section of perithecium. Scale is 0.1 mm. b. Thallus of Verrucaria striatula. Scale is 1 mm. ANNOTATED LIST OF SPECIES Where distributions were derived from the literature only, author and date are given. All other specimens were examined by the author. Where such specimens were collected by others, the col- lector s name is given followed by the identification of the herbar- ium retaining the specimen. The remaining distributions are from the authors collections. Genus Arthopyrenia Arthopyrenia halodytes (Nyl.) Arn. Ber. Bayer. Bot. Ges. 1:122. 1891. Verrucaria halodytes Nyl. Mem. Soc. Sci. Nat. Cherbourg 5:212. 1857. DESCRIPTION: Thallus epilithic (siliceous rock), endolithic (calcareous rock and shells), yellowish if epilithic, greyish or blackish-brown if endolithic. Perithecium almost wholly immersed in substrate or sessile with black hemispherical to broadly conical involucrellum, 0.15 to 0.5 mm diameter, excipulum colorless to pale brown. Spores eight per ascus, ovoid, two-celled, one cell usu- ally broader than the other, 9-20 x 4-7.5/nm. Swinscow (1965) considered this to be the only littoral species of the genus and treated A. sublitoralis (Leight.) Arn. , A. foveolata A. L. Sm. and A. gyalectoidea Knowles as synonyms and reported a range of 10-20 x 5-10/mi in spore size. Richard C. Harris (1975) treats this species as co. ,a Pyrenocollema. Arthopyrenia halodytes is often associated with shells or calcareous rocks but may also be found on siliceous rock. GENERAL DISTRIBUTION: Worldwide on marine shores (Santesson 1939:52-63). NORTHEASTERN AMERICAN DISTRIBUTION: NEW JERSEY: Cape May Co. CONNECTICUT: New London Co. RHODE ISLAND: Newport Co. MASSACHUSETTS: Barnstable Co. , Plymouth Co. , Essex Co. MAINE: Cumberland Co. , Sagada- hoc Co., Hancock Co., Washington Co. NOVA SCOTIA: Yar- mouth Co., Digby Co., Halifax Co., Victoria Co., Cape Breton Co. NEWFOUNDLAND: West Coast Section, Northern Penin- sula Section, East Coast Section, Avalon Section. Genus Caloplaca All of the littoral species of Caloplaca collected belong to the section Gasparrinia. Caloplaca marina (Wedd.) DuRietz, Method. Grund. Modern. Pflanzensoziol. 170. 1921. Lecanora marina Wedd. Mem. Soc. Sci. Nat. Sherbourg 19:275. 1875. DESCRIPTION: Thallus orange yellow to red orange, citrine in shade, orbicular, irregular, orsubeffuse, small convex lobes contig- uous or. in center of thallus, minutely granular or tuberculate, whit- ish prothallus sometimes visible. Apothecia reddish-orange, 0.5-1.0 mm diameter, plane to convex, margins entire orcrenulate. Spores ellipsoid, polarilocular, isthmus about 0.3 length of spore, 10-14 x 5-7^m. Wade (1965) found this species often associated with Caloplaca thallincola and Verrucaria maura in the British Isles. Caloplaca thallincola has not been collected, however, in the littoral zone of North America. The white hypothallus is seen in young growth between the small subconvex lobules. GENERAL DISTRIBUTION: Norway, Sweden, Poland (Nor- din 1972). Finland (Rasanen 1927), Germany (Erichsen 1957), Novaya Zemyla (Lynge 1928), England (Ferry and Sheard 1969), Wales (Fletcher 1973b), France (Werner MSC). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Cumberland Co., Hancock Co. NOVA SCOTIA: Yarmouth Co.. Digby Co., Shelburne Co.. Halifax Co. NEWFOUNDLAND: Northern Peninsula Section. 15 Caloplaca microthallina (Wedd.) Zahlbr. Cat. Lich. Univ. 7:247. 1931. Lecanora microthallina Wedd. Mem. Soc. Sci. Nat. Cher- bourg 19:276. 1875. DESCRIPTION: Thallus citrine, 1-3 mm diameter, comprised of scattered lobes on the periphery, scattered granules toward center, forming patches on rocks, lobes convex, 1-2 times as long as broad, tending toward granules near center of patches. Apothecia yellow to pale orange, 0. 15-0.8 mm diameter, margins crenulate or entire. Spores oblong-ellipsoid, polarilocular, isthmus ca. 0.3 the length of the spores, 10-18 x 5-8/im. Caloplaca microthallina is distinguished by its minute granular thallus forming patches up to 3 mm diameter and by its citrine color. Wade (1965) found it often associated with Verrucaria maura in the British Isles. This also holds true for North America. This species is not previously reported from North America. In Europe this species is not commonly reported from the littoral zone. GENERAL DISTRIBUTION: Norway, Sweden, Finland, Den- mark (Nordin 1972). NORTHEASTERN AMERICAN DISTRIBUTION: NOVA SCOTIA: Digby Co., Halifax Co., Cape Breton Co. NEW- FOUNDLAND: West Coast Section, Northern Peninsula Section. Caloplaca scopularis (Nyl.) Lett. Hedwegia 52:242. Lecanora scopularis Nyl. Flora 66: 105. 1883. 1912. DESCRIPTION: Thallus yellow orange to deep orange, radiate, up to 1.5 cm diameter, lobes narrow, 0.25-0.3 x 0.5-2.0 mm, con- vex, apices crenulate or branched, center of thallus usually thickly covered with apothecia. Apothecia orange, 0.5-0.75 mm diameter, margins entire. Spores ellipsoid, polarilocular, 10-15 x 5-7/un, isthmus ca. 0.3 the length of the spore. Caloplaca scopularis is unique among the littoral Caloplacae due to its radiating thallus. Wade (1965) indicated that this species resembles a small form of C heppiana or C. thallincola but is dis- tinquished by ellipsoid spores and the submoniliform nature of the upper parts of the paraphyses. GENERAL DISTRIBUTION: Novaya Zemlya (Lynge 1928), Norway, Sweden, Denmark (Nordin 1972), Finland (Rasanen 1927). Germany (Erichsen 1957), Japan (Nylander 1890). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Cumberland Co., Hancock Co. NOVA SCOTIA: Halifax Co., Vic- toria Co. NEWFOUNDLAND: West Coast Section, Avalon Sec- tion. Caloplaca verruculifera (Vain.) Zahlbr. Cat. Lich. Univ. 7:272,1931. Placodium verruculifera Vainio in Med. om Grdn. 30:313. 1905. DESCRIPTION: Thallus orange or yellow, up to 3 cm diameter, or dispersed, lobes 3-5 mm long, convex, center of thallus areolate, granular, isidia globose, spores oblong-ellipsoid, polarilocular, isthmus ca. 0.3 length of spore, 9-14 x 4-6/xm. Specimens of this species, previously unreported from North America, were identified for the author by J. Poelt. It is easily con- fused with Caloplaca granulosa which also has globose isidia but has smaller rosettes of 1-1.5 cm and shorter lobes of about 2 mm (Poelt 1969). GENERAL DISTRIBUTION: Norway, Sweden, Finland, and Siberia (Nordin 1972). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Sagadahoc Co., Hancock Co. NEWFOUNDLAND: West Coast Section. Genus Lecanora Lecanora grantii Magn. Ann. Cryptog. Exot. 5(1):21. 1932. DESCRIPTION: Thallus of irregular whitish-grey large gran- ules, KOH + yellow, medulla with small crystals. Apothecia con- cave to plane, thalline margin regular to crenulate; hymenium dark reddish-brown, 1+ dark blue; epithecium with small crystals, insoluble in KOH. Spores eight per ascus, oblong-ovoid, 11-18 x 6-8.5/an. Little of this species was collected since it extends down only into the upper limits of the littoral zone. The scant material collected conforms to the original material described from a log on a sea beach by Magnusson (1932). GENERAL DISTRIBUTION: Washington (Magnuson 1932), British Columbia (Brodo MSC). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Sagadahoc Co. NEW YORK: Suffolk Co. (Latham MSC). NOVA SCOTIA: Shelburne Co. NEWFOUNDLAND: West Coast Sec- tion. Genus Lichina Lichina confinis (O Mull.) Ag. Sp. Algar. 1:105. 1821. Lichen Confinis O. Mull. Icon. PI. Daniaw 5:5. 1872. DESCRIPTION: Thallus fruticose, branches rounded in cross section, blackish-brown, phycobiont Calothrix. Ascocarps termi- nal, globose, perithecoid, small ostioles. Spores colorless, simple ovoid, 15-24 x 12-15/mi. Lichina confinis, appearing as black tufts in the upper limits of the littoral zone, is the only fruticose lichen found in the area included in this treatment. GENERAL DISTRIBUTION: England (Ferry and Sheard 1969), Wales (Fletcher 1973b), Finland (Rasanen 1927), Germany (Degelius 1939), Italy (Jatta 1909-1911), Norway (Havaas MSC), Sweden (Degalius MSC). NORTHEASTERN AMERICAN DISTRIBUTION: MASSA- CHUSETTS: Essex Co. (Tuckerman 1882). NOVA SCOTIA: Cape Breton Co. (Lamb 1954). NEWFOUNDLAND: East Coast Section, Northern Peninsula Section, West Coast Section. Genus Stigmidium Stigmidium marinum (Deak.) Swins. Lichenologist 3:55. 1965. Sagedoa marina Deak. Ann. Mag. Nat. Hist. I. 12:40, pi. 4, f. 13. 1954. 16 DESCRIPTION: Parasymbiont on littoral Verrucariae, espe- cially V. mucosa and V. microspora, lacking a visible thallus of its own. Perithecia usually resembling that of host lichen, totally immersed on V. mucosa and hemispherical on V microspora . Invo- lucrellum black with pigment extending into hyaline excipulum. Spores eight per ascus, two-celled with each cell often divided by pseudosepta, upper cell usually slightly wider than the lower, 10-15 x 3.5-5ftm. The perithecia of Stigmidium are easily confused with that of the host. Stigmidium, however, has two-celled spores of 10-15 X 3.5- 5fm\. Swinscow (1965) reported spores 10-15 x 4-6/rni. The com- bination Stigmidium marinum was made by Swinscow when he united Arthopyrenia marina (Deak.) A. L. Sm and A. leptotera (Nyl. ) Arn. Neither of these species appear in the North American checklist (Hale and Culberson 1970) nor did Swinscow (1965) report a specimen from North America. This, therefore, represents a new record for North America. GENERAL DISTRIBUTION: Germany, Finland, Ireland, Jer- sey, England (Swinscow 1965). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Cumberland Co., Hancock Co. NEW JERSEY: Ocean Co. NEW- FOUNDLAND: Avalon Section. Genus Verrucaria The species of this genus form crusts which may be continuous or form scattered patches, rimose areolate or divided into discrete are- oles or lobes. The thalli vary in thickness from 20 to 500/mi, and may be almost completely transparent to entirely opaque. In some species, the transparency of the thallus may be enhanced by wet- ting, while others remain opaque when wet. The thalli may be smooth or roughened by dark points or ridges. The ridges, called juga (Santesson 1939), vary in length, width, and thickness. The exact origin and ontogeny of the juga is not known but it appears that they originate at or just below the surface of the thallus. In the authors experience, they do not extend to the substrate except at the edges of the areoles. Often a distinction is made in keys between point and ridge forms of the juga, but it is common that the points are merely peaks on inconspicuous or hidden ridges. The perithecia of all of the littoral Verrucariae, with which the author has worked, have a dark involucrellum which may spread widely or be closely appressed to the excipulum. This darkening may extend into the lower excipulum, terminating a short distance below the involucrellum proper or it may not extend into the lower excipulum. The darkening may occur intermittently or continu- ously throughout the lower excipulum. This darkening is given considerable taxonomic importance by Servi't (1954) and by Erich- sen (1957) but Swinscow (1965) discounted this importance on the grounds that it is highly variable within a species. The author con- curs with Swinscow in this view. Perithecial size is not, in itself, very useful in distinguishing species. Perithecium diameters vary generally between 0.05 and 0.7 mm and these dimensions overlap considerably between Verrucaria species. Although vertical sec- tions are illustrated in the key, none is claimed to be typical for there is much variation in many, if not all species. Santesson (1939) has noted the high variability of spore size in littoral pyrenolichens and suggested that they should not be given great taxonomic importance. All spores in Verrucaria are simple and hyaline. For the most part, the spores are thin walled and of similar size, occurring eight per ascus. Verrucaria intemigrescens and V. silicicola are the notable exceptions to the above in north- eastern North America. The spores of V. intemigrescens are thick walled and those of V. silicicola are unusually large. The remainder are ovoid to reniform and exhibit overlapping size ranges between species. Verrucaria amphibia R. Clem. Ess. Var. Veg. Andalucia 299. 1807. DESCRIPTION: Thallus continuous to rimose areolate, black when dry, translucent green to amber when wet, with irregular black ridges often enclosing lenticular areas 50-100/im thick. Perithecia large (13-16 mm), prominently elevated, often flattened or concave on top, vertical and horizontal ridges forming reticular pattern, lenticular areas often enclosed by ridges at base; excipu- lum hyaline to partly darkened below. Spores hyaline, ovoid, 7-19 X 4-7. 5^m. This species might readily be confused with V. maura. Both spe- cies have dark thalli with juga forming pegs or ridges and with robust perithecia. However, they are easily distinguished on closer examination. Whereas V. maura tends to have points raised above the thallus, V amphibia tends toward ridges. The ridges tend to enclose lenticular areas on a dry thallus giving the impression of ripples on water. When wet, V. amphibia becomes more translucent and light colored against which the black ridges become contrasted. The thallus of V. maura remains dark when wet except on very thin juvenile specimens. The thallus of V amphibia tends to be continu- ous whereas that of V. maura tends to be rimose areolate but in nei- ther case are the characters absolute. Areolation appears to develop and increase with age in V. amphibia. Verrucaria amphibia pro- duces large, steep sided perithecia often strongly depressed on top, a form also produced in some instances by V. maura. Such perithe- cia of V. amphibia have two characteristics not demonstrated by V maura; whereas V. maura may have many fine points or pegs cov- ering the perithecium, the design on V. amphibia is a reticulum of vertical and horizontal ridges. Also, where the V. amphibia perithe- cium meets the thallus, the ridges tend to enclose areas of ovoid shape and appear light and translucent when wet (see the Key). Verrucaria amphibia is little discussed in literature. Santesson 2 says that it is not known from Scandinavia, although it occurs in England. Ferry and Sheard (1969) included V. amphibia in their key but did not deal with it in detail . The author first became acquainted with it by examining herbarium specimens and his measurements should not be regarded as limits due to the small amount of material examined. There is no prior report of this species from North America. GENERAL DISTRIBUTION: England (Ferry and Sheard 1969), Wales (Fletcher 1973a), Germany (Ullrich MSC). NORTHEASTERN AMERICAN DISTRIBUTION: NEW- FOUNDLAND: East Coast Section, Avalon Section. Verrucaria ceuthocarpa Wahlenb. in Ach. Suppl. Meth. Lich. 22. 1803. DESCRIPTION: Thallus brown, rimose areolate, glabrous, forming discrete areoles or lobes, ridges absent, perithecia sub- : R. Santesson. Director. Systematic Institute of Oslo. Oslo. Norway, pers. commun. November 1966. 17 merged, 0.1-0. 15 mm wide, involucrellum usually brown, excipu- lum hyaline to dark below, spores hyaline, ovoid 8-10 x 5-8/mi. Verrucaria ceuthocarpa is easily confused with Verrucaria dege- lii when either is modified by environment or when its structure is obscured by epiphytic algae. The clefts of V. cethocarpa may become darkened and, on cursory examination, may resemble the dark ridged border of areoles of V. degelii. Careful examination is needed to observe the absence of ridges. Conversely sometimes the ridges are scant on a thallus of V. degelii and it may by mistaken for that of V. ceuthocarpa. Perhaps the greatest obstacle to correct identification is obscur- ing of surface detail by epiphytic algae. Portions of questionable thalli should be flooded with water to soften and expand the algae. If details are still obscured, the flooded portion can be scrubbed with a small water color brush. True ridges are fairly resistant to such gentle abrasion and will persist until the thallus becomes too softened by the water to maintain its integrity. According to Santessons key (1939), the prime diagnostic feature of V. degelii vs. V. ceuthocarpa is the presence of ridges on V. degelii. The author finds that two other features are quite useful. The best of the two is tendency for flatness to concavity between ridges of an areole of V. degelii compared with the convexness of areoles and branches thereof in V. ceuthocarpa. Verrucaria ceuthocarpa is truly glabrous. Further, from the limited material in the authors three North American collections it also appears that the involucrellum of V. ceuthocarpa tends to be brown whereas that of V. degelii is dis- tinctly black. GENERAL DISTRIBUTION: Northern Europe, Spitsbergen, Bear Island, Novaya Zemlya, Siberia, Bering Straits, Greenland, Kerguelen, Antarctica (Lamb 1953); Washington U.S.A. (collected by Fink and determined as Verrucaria maura by Zahlbruckner MSC). NORTHEASTERN AMERICAN DISTRIBUTION: NEW- FOUNDLAND: East Coast Section. underlying thallus and reduce the growth of ridges. On the other hand, a growth of dark algae on V. ceuthocarpa, especially when dry, may obscure the color and glabrous nature of the thallus and give the illusion of ridges on the edge of areoles. One cannot over-emphasize the importance of detecting and removing such epiphytic algae! The thallus of V. degelii varies greatly in thickness and transpar- ency depending on age or extent of development. It is almost always areolate, with only one known exception. In that case, a rather large area of smooth, continuous thallus was surrounded by a raised black ridge and a crack, also bordered by a black raised ridge, extended inward toward the center. At the edges of this patch of thallus was more thallus divided into typical discrete areoles with similar black borders. More commonly a young thallus is thin, nearly transparent, smooth and brown to tan. It is areolate and is often divided into lobes by a dendritic pattern of grooves. In such a thallus, the grooves are usually hyaline. The ontogeny of these lichens has not been studied and must be inferred from observations of what could as easily be the results of conditions of growth as of aging. It appears, however, that older thalli thicken and develop discrete areoles, usually with black borders and frequently with black lines connecting them with the perithecium. These areas of blackness then seem to proliferate under some condi- tions to produce unelevated patterns or raised juga. Sometimes the black area extends beneath the perithecium and sometimes it does not. The perithecium is commonly immersed, with or without raised ridges around the ostiole. At times there is a convex area raised around the ostiole. The author has seen prominently raised convex perithecia on the same thallus as sunken perithecia. The degree of perithecial elevation appears to be a variable character of the species. Spores are ovoid but sometimes pointed when young. A clear spot commonly, although not always, appears in the center of the younger spores. Santesson (1939) reported the range of spore sizes for Verru- caria degelii as 10-13 x 5-6/xm, which is consistent with that observed by the author. GENERAL DISTRIBUTION: NORWAY (Santesson 1939). Verrucaria degelii R. Sant. Ark. Bot. 29A (10):31. 1939. DESCRIPTION: Thallus rimose, forming lobes or discrete are- oles, amber, brown or black when dry, amber to brown when wet, prominent black ridges bordering areoles and often perithecia, thin to thick (100-320 mm). Perithecia sunken to prominently raised, 0.1- 0.25 mm diameter, excipulum hyaline. Spores hyaline, ovoid 9-13 x 5-6/*m. Though published in 1939, this species was known only from Nor- way until the authors collections, thus there are few specimens and little study of ecology upon which to base conclusions about environ- mental influences on variations. It is reasonable to assume, however, that the nature of variations is consistent with that seen in other Verru- cariae. If so, color would be lighter in shade forms than sun forms and ridges would be fewer and thinner in shade forms than on sun forms. This kind of variation is probably the cause of confusion of some specimens of V. degelii with V. ceuthocarpa. The identity of a robust specimen of V. degelii is beautifully clear. However, the ridges may become scant and the specimen strongly resembles the morpho- type of V ceuthocarpa with darkened clefts between areoles. A sec- ond source of confusion is the epiphytic growth of algae on thalli of either V. degelii or V ceuthocarpa. A growth of algae on V. degelii can obscure ridges and produce the glabrous appearance of V. ceutho- carpa. Such a growth can also produce a shade condition for the NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Hancock Co.. Washington Co. MASSACHUSETTS: Essex Co. NOVA SCOTIA: Yarmouth Co.. Digby Co., Halifax Co. NEW- FOUNDLAND: West Coast Section, Northern Peninsula Section. East Coast Section. Avalon Section. Verrucaria ditmarsica Erichs. Schriften Naturwiss. Vereins Schleswig-Holstein 22:90. 1937. DESCRIPTION: Thallus entire, olivaceous, with pegs to short ridges, thin (20-50^m). opaque to translucent when dry, more translucent when wet. Perithecia slightly dome-shaped to globose (usually hemispherical), 0.1-0.25 mm diameter, usually shiny; excipulum hyaline to dark below. Spores ovoid to reniform. color- less, 6-1 1 x 3.5-6ftm. The thallus of Verrucaria ditmarsica is usually olivaceous, but the darkness varies with light exposure. In bright light the thallus is dark olive and if grown in the shade it is a very light olive green. It usually is rather transparent to translucent. The transparency is increased by wetting upon examination. Short, mostly straight ridges are characteristic on the thallus. These become reduced in size and frequency in the shade modification. In this reduced condi- tion it is easily confused with the shade modification of V. erich- senii and especially with V. striatula whose color is also similar. Ridges often merge with the perithecia at the base. The perithecia are convex to hemispherical and usually shiny. Darkness of the lower excipulum is a highly variable factor. Gener- ally some carbonaceous granules tend to extend below the involu- crellum and may continue somewhat throughout the lower involucrellum (see the key). However, the species should not be characterized as having an involucrellum that is dark below, a view adopted by Erichsen (1957). GENERAL DISTRIBUTION: Germany (Erichsen 1957), Nor- way (Santesson MSC). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Cumberland Co., Sagadahoc Co., Hancock Co. RHODE ISLAND: Newport Co. MASSACHUSETTS: Plymouth Co., Essex Co. NEW HAMPSHIRE: Rockingham Co. NOVA SCO- TIA: Yarmouth Co., Digby Co., Shelburne Co., Halifax Co., Vic- toria Co. NEWFOUNDLAND: West Coast Section, Northern Peninsula Section, East Coast Section. Not previously reported from North America. Verrucaria erichsenii Zsch. in Erichs. Verh. Bot. Vereins Prov. Brandenburg 70: 192. 1928. DESCRIPTION: Thallus entire or areolate, black to blackish- brown dry, amber and more translucent when wet, roughened by rows of pegs or ridges; ridges often branched, sometimes sub- merged in thallus and visible only when wet; thallus 30-70/mi thick. Perithecia elevated, conical to hemispherical, spreading in irregular pattern at base, often with pegs or ridges as on thallus, 0. 1-0.3 mm diameter, excipulum hyaline below. Spores ovoid, col- orless, 8-9 x 4.5-7/xm. Verrucaria erichsenii demonstrates considerable thallus varia- tion. It is usually considered to be clearly rimose or areolate. Typi- cally this is so but it is not uncommon to find a thallus of V. erichsenii continuous in an especially wet environment, where the thallus becomes thick and gelatinous. When dry the thallus is usu- ally blackish-brown to black. A grey morphotype with a texture like that of graphite was collected in the Narragansett Bay area. When moistened during examination the thallus increased in trans- parency, one of the best tests of questionable thalli. When wetted they reveal a pattern of black markings typical of the pattern of ridges usually seen above the surface. The thallus of V. erichsenii typically has short, often branched irregular ridges or rows of points, frequently confluent with or continuing up over the perithe- cia. Ridges are longer than wide and rarely very high. In extreme circumstances ridges become higher and sharper forming cusps and aretes. In other extremes they may be immersed within the thallus to be revealed only by wetting. The most consistent character of the perithecium appears to be the irregular spreading base which seems most pronounced when viewed from above a wet thallus or when the thallus has been peeled from the rock and placed on a slide and illuminated from below. The diameters of perithecia tend to fall between 0. 1 and 0.3 mm. Zschacke (1934) and Erichsen (1957) both list a spore range of 8- 12 x 5-7/mi which agrees with the authors observations. GENERAL DISTRIBUTION: Germany (Erichsen 1957), Brit- ish Columbia (Ohlsson MSC), Sweden (Santesson MSC), Norway (Santesson MSC), Wales (Brodo MSC), Scotland (Brodo MSC). NORTHEASTERN AMERICAN DISTRIBUTION: MAINE: Cumberland Co., Sagadahoc Co., Hancock Co., Lincoln Co. (Merrill MSC), Washington Co. MASSACHUSETTS: Essex Co., Bristol Co. (Willey MSC), Plymouth Co., Barnstable Co. RHODE ISLAND: Newport Co., Washington Co. CONNECTICUT: New London Co. NEW HAMPSHIRE: Rockingham Co. NOVA SCO- TIA: Yarmouth Co. , Digby Co. , Shelburne Co. , Halifax Co. , Vic- toria Co., Cape Breton Co. NEWFOUNDLAND: West Coast Section, Northern Peninsula Section, Avalon Section. Verrucaria internigrescens (Nyl.) Erichs. Vern. Bot. Vereins Prov. Brandenburg 70:193. 1929. Verrucaria aethiobola van Interni- grescens Nyl. in Brenner, Meddeland. Soc. Fauna Fl. Fenn 13:125. 1886. DESCRIPTION: Thallus of brown areoles connected by darker brown prothallus. Perithecia brown, convex, 0.2-0.34 mm diame- ter, excipulum hyaline or intermittently darkened below. Spores hyaline, thick walled, fusiform, (11.5) 15-23 (27) x (4) 6-8 (14)/mi. The brown prothallus, thallus. and perithecia are distinctive. The thallus is thin by comparison with other areolate forms such as V. maura and V. ceuthocarpa. The spores are distinctive, being fusi- form and thick walled. Erichsen (1957) reported a spore range of 15-27 x 7-12/im. As indicated above, spores were found in the North American collections as large as reported by Erichsen but they were bloated and of atypical shape. Most spores seen were in the range of 15-23 X 6-8/un. Erichsen (1957) listed this species as both littoral and nonlittoral, therefore, it may be assumed to be facultative in its habits. This species was collected at only one locality in North America and this is the first record from North America. GENERAL DISTRIBUTION: Germany (Erichsen 1957). NORTHEASTERN AMERICAN DISTRIBUTION: NEW- FOUNDLAND: Avalon Section. Verrucaria maura Wahlenb. in Ach. Suppl. Meth. Lich. 19. 1803. DESCRIPTION: Thallus dark, usually black to brownish-black, sometimes green, opaque (wet or dry), rimose areolate, usually with small black pegs or points (sometimes obscured by epithallic algae), thin to thick (75-300 /mi). Perithecia small to large (usually large) 0.3-0.7 mm diameter, sunken to prominently raised tops rounded to concave, may be covered visibly by pegs, excipulum entirely black below. Spores ovoid, hyaline 10-20 x 7-10/