132. Cladonia ] 34. CLADONIACEAE 243 



to large, 2-4 mm. across, the disk strongly convex, flesh-colored, the exciple soon 

 covered; spores oblong-fusiform to fusiform, 11-23 X 3-4 p. 

 On sterile soil, Florida. 



131. Pilophorus T. Fries, Ster. Pil. Comm. 40. 1857. 



Primary thallus crustose, minutely granulose, rudimentary, devoid of differen- 

 tiation into layers, attached to the substratum by hyphal rhizoids, often disappear- 

 ing; podetia arising from the primary thallus, cylindrical, rarely branched, solid or 

 hollow, decorticate and commonly granulose and covered with thalloid warts, the 

 central portion composed of loosely interwoven, longitudinally extending hyphae, 

 surrounded by mechanical tissue of densely packed hyphae; apothecia small to 

 middle-sized, borne at the apices of the podetia, the disk subglobose to subcorneal, 

 commonly black, the exciple soon disappearing; hypothecium brownish to dark 

 brown; hymenium brown; paraphyses unbranched, becoming indistinct; asci cla- 

 vate; spores 8, hyaline, ellipsoid to oblong-ellipsoid, non-septate. 



The algal host is Pleurococcus. 



A. Apothecia large, vertically elongated, 2-3 X 1 mm 3. P. Hallii 



A. Apothecia smaller, round, not more than 2 mm. across 



B. Podetia unbranched, granulose to subsquamulose 2. P. Fibula 



B. Podetia rarely branched, warty-granulose or somewhat powdery . 1. P. cereolus 



1. Pilophorus cereolus (Ach.) T. Fries, Lich. Scand. 1:55. 1871. 



Lichen cereolus Ach., Lich. Suec. 89. 1798. P. cereolus var. acicularis (Ach.) 

 Tuck. 



Primary thallus effuse at the base, forming a warty-granulose or powdery, 

 grayish white crust; podetia arising from the primary thallus, short, erect, cylin- 

 drical, rarely branched, clustered or scattered, warty-granulose or somewhat 

 powdery, greenish gray to ashy or rarely greenish; apothecia small, 0.6-2 mm. 

 across, borne on the tips of the podetia, subglobose to subcorneal, black; spores 

 ellipsoid-fusiform, 16-23 X 5-8 /t. 



On rocks, Minnesota, California, Oregon, and Washington, and eastward into 

 the Rocky Mountains. 



2. Pilophorus Fibula (Tuck.) T. Fries, Ster. Pil. Comm. 42. 1857. 



Stereocaulon Fibula Tuck., Syn. Lich. 46. 1848. P. cereolus var. Fibula Tuck. 



Primary thallus minutely granulose to somewhat areolate, greenish gray to 

 brownish, soon disappearing; podetia arising from the primary thallus, solid, erect, 

 unbranched, very short to somewhat elongated, granulose to subsquamulose; apo- 

 thecia small, 0.6-1 mm. across, borne on the tips of the podetia, subglobose, black; 

 spores ellipsoid to ellipsoid-fusiform, 17-26 X 5-8 fi. 



On rocks, Vermont and northern New York. 



3. Pilophorus Hallii (Tuck.) Vainio, Bot. Mag. Tokyo. 35:59. 1921. 

 P. acicularis f. Hallii Tuck., Proc. Am. Acad. 12:177. 1877. 



Primary thallus warty-granulose or powdery, greenish gray to ashy or brown- 

 ish; podetia arising from the primary thallus, erect, solid, scarcely ever branched, 

 short and stout, minutely granulose or powdery; apothecia small to middle-sized, 

 vertically elongated, 2-5 X 0.5-1 mm., almost cylindrical, black, borne on the tips 

 of the podetia; spores ellipsoid to ellipsoid-pointed, 18-24 X 5-8 [x. 



On rocks, Washington and Oregon. 



132. Cladonia Hill; Web., in Wigg., Prim. Fl. Hols. 90. 1780. 



Primary thallus composed of squamules, persistent or dying, ascending and 

 foliose or horizontal and crustose, becoming rough and warty, the upper side 

 corticate, the lower side and rarely the upper decorticate and sorediate; podetia 

 arising from the squamules of the primary thallus or from old podetia, often dying 

 at the base, cylindrical, trumpet-shaped, or variously irregular, with or without 



