merged. 0. 1-0. 15 mm wide, involucrellum usually brown, excipu- 

 lum hyaline to dark below, spores hyaline, ovoid 8-10 x 5-8fim. 



Verrucaha ceuihocarpa is easily confused with Verrucariu tlege- 

 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. degetii. 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. ceulhncarpu . 



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 ndges 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 pnme diagnostic feature of 

 k' 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 tlatness to concavity between ndges of an 

 areole of V. degelii compared with the convexness of areoles and 

 branches thereof in V ceiilhocarpa. Verntcaria ceulhoearpii is truly 

 glabrous. Further, from the limited material in the authors three 

 North American collections it also appears that the involucrellum of 

 V ceuthocarjxi tends to be brown whereas that of V. degelii is dis- 

 tinctly black. 



GENERAL DISTRIBUTION: Northern Europe. Spitsbergen, 

 Bear Island, Novaya Zemlya, Sibena. Bering Straits. Greenland, 

 Kerguelen, Antarctica (Lamb 1953); Washington U.S.A. (collected 

 by Fink and determined as Verruearici nuiiira by Zahlbruckner 

 MSC). 



NORTHEASTERN AMERICAN DISTRIBUTION: NEW- 

 FOUNDLAND: East Coast Section. 



underlying thallus and reduce the growth of ndges. On the other 

 hand, a growth of dark algae on V ceuthoearpa, especially when dry, 

 may obscure the color and glabrous nature of the thallus and give the 

 illusion of ndges on the edge of areoles. One cannot (wer-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 

 ndge and a crack, also bordered by a black raised ridge, extended 

 inward t(iward 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 dendntic 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 

 conditionsof 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 pentheciuni. 

 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 docs 

 not. 



The penthecium is commonly immersed, with or without raised 

 ndges aniund the ostiole. At times there is a convex area raised around 

 the o.stiole. The author has seen prominently raised convex perithecia 

 on the same thallus as sunken perithecia. The degree of penthecial 

 elevation appears to be a vanable 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. Sanlesson (1939) reported the range of spore sizes for Verru- 

 cariu degelii as 10-13 '■ 5-6/im. which is consistent with that 

 observed by the author 



GENERAL DISTRIBUTION: NORWAY (Santesson 1939). 



Vemicaria degelii R. Saiit. Ark. Bot. 29A (10)31. 19.^9. 



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 (l(K)-320 mm). Perithecia sunken to prominently raised, 0.1- 

 0.25 mm diameter, excipukim hyaline. Spores hyaline, ovoid 9-13 x 

 5-6/(m. 



Though published in 1*^39. this species was known only from Nor- 

 way until the author's collections, thus there are few specimens and 

 little study of ecology upon which to base conclusions about environ- 

 mental intlucnces on variations. It is reasonable to assume, however, 

 that the nature of variations is consistent with that seen in other Vemi- 

 canae. If so. color wduUl he lighter in shade forms than sun lorms 

 and ndges would be fewer and thinner in shade forms than on sun 

 forms. This kind of variation is probably the cause of confusion o\ 

 some specimens of V degelii with V ceiilhocarpa . 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- 

 lype of V ceutluKurjui with darkened clefts between areoles. A sec- 

 ond source of conftision is the cpiphvtic growth of algae on thalli of 

 cither \' degelii or 1.' ceiithtHiirpa- A growth of algae on I,' degelii 

 can obscure ndges and produce the glabrous appearance of I.' cemlu>- 

 carpu. 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, 



I'erntcana diliiiarsua 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. Pcnthecia slightly dome-shaped to globose 

 (usually henusphencal). 0.1-0,25 nnii diameter. usualK shiny; 

 excipulum hyaline to dark below. Spores o\i>id to reniform. color- 

 less, 6-1 1 X 3.5-6^(111. 



The thallus of Verntcaria ditinarsiva is usually olivaceous, but 

 the darkness varies with light exposure. In bnght 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 

 ndges are charactenstic on the thallus. These become reduced in 

 size and frequency in the shade modification. In this reduced condi- 

 tion it is easily confu.sed with the shade modification of I,' erich- 



18 



