Marine Flora and Fauna of the Northeastern 



United States. Lichens (Ascomycetes) of 



the Intertidal Region 



RONALD M.TAYLOR' 



ABSTRACT 



Thi> manual ircals (he lichens lound in ihc intertidal region trom New Jersey to Newloundland Methods of 

 collection, preparation, and study are briefly treated. Twenty-two species are covered, both in an illustrated key 

 and an alphabetical listing, witfi brief descriptions and notes on ecology and dislribution. A glossary of terms is 

 included 



INTRODUCTION 



METHODS OF COLLECTION AND STUDYING 



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 inquines directed to the author that the manne 

 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 <ir 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 manne lichens 

 treated in this manual, except for the genus Lichiiui. are fungus 

 dominated and the fungus is an Ascomycete. 



Manne lichens occur in three growth forms: fruticose. foliose. 

 and cru.stose . Fruticose forms are usually upnght or pendant in rela- 

 tionship to the substrate; they stand out away from the substrate. 

 Lichiiia. 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, Anhopyrenia halodyles. 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 facultatn c lichen is its occurrence 

 with, or at the same height on the shore as, an obligate marine 

 species. 



'Science Depariment. Lansing Conimuniiv College. Lansing. MI 48914 



Manne 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. 

 Unfonunately. 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 cau.ses excessive reticulation that is detrimental 

 to futjire 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 Bnght illumination is important because of the dark color 

 of many thalli, especially in the genus Verrucana. 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. 



