!58 28. COLLEMACEAE [103. Collema 



quadrangular or ellipsoid, 1-3-septate transversely and 1-2-septate longitudinally, 



10-21X7-11/1. 



On trees and old wood, from Massachusetts westward to Illinois. 



3. Collema tenax (Swartz) Ach., Lich. Univ. 635. 1810. 

 Lichen tenax Swartz, Nov. Act. Soc. Sci. Ups. 4:249. 1784. 

 Transforming the algal colony into a round or somewhat irregular, yellowish 



green or darker body, the lobes thin and closely adnate or rarely more loosely 

 attached and folded; apothecia small to middle-sized, 0.5-2 mm. across, immersed 

 to partly superficial, the disk concave to flat, reddish brown, the algoid exciple 

 sometimes crenate; hypothecium brownish; spores ovoid-ellipsoid, 3-septate trans- 

 versely and 1-septate longitudinally, 16-24 X 8-11 /a. 



On calcareous soil, throughout eastern United States, and westward to Missouri 

 and Minnesota. 



4. Collema pustulatum Ach., Syn. Lich. 317. 1814. 



Transforming the algal colony into a more or less irregular, brownish olive or 

 darker, lobed body, the lobes becoming long and narrow and subdichotomously 

 or irregularly divided and often ascending, the more closely attached central lobes 

 commonly dying, leaving the marginal lobes often separately attached to the sub- 

 stratum; apothecia minute to small, 0.2-0.7 mm. across, immersed to adnate, 

 appearing like pustules on the lobes, the disk concave to flat, reddish to blackish 

 brown, the algoid exciple prominent; hypothecium hyaline to cloudy; spores ovoid- 

 ellipsoid, 3-septate transversely and 1-septate longitudinally, 12-24X9-10//.. 



On calcareous rocks, from Pennsylvania to Alabama, and westward to Iowa and 

 Minnesota. 



var. heterosporum Fink; Hedrick, Mycologia 26:154. 1934. 



Spores oblong-ellipsoid with one end slightly flattened, 3-5-septate transversely 

 and 1-3-septate longitudinally, or rarely spheroidal and 3-5-septate transversely 

 and longitudinally, 25-28X13-14/1, irregularly or rarely uniseriately arranged. 



On rocks, Florida. 



5. Collema crispum (L.) Wigg., Prim. Fl. Hols. 89. 1780. 



Lichen crispus L., Flora Suec. II. 406. 1755. 



Transforming the algal colony into a small, rather thin, olive-green or darker, 

 round or somewhat irregular, lobed body, the marginal lobes more or less expanded, 

 those of the center raised and folded with dentate or granulate edges; apothecia 

 middle-sized or larger, 0.7-2.5 mm. across, often numerous and nearly concealing 

 the central part of the thallus, partly superficial, the disk concave, dark reddish 

 brown, the algoid exciple entire to more commonly crenate-granulate ; hypothecium 

 brownish; spores oblong-ellipsoid, 3-septate transversely and 1-2-septate longi- 

 tudinally, 16-30 X 8-12 p. 



On soil, throughout northern United States. 



6. Collema cheileum Ach., Lich. Univ. 630, 631. 1810. 



Lichen cheileus Ach., Lich. Suec. 134. 1798. Collema cheileum var. mono- 

 carpon (Duf.) Leight. 



Transforming the algal colony into a greenish black to olive-green, lobed body, 

 the lobes minute or small, loosely imbricated, round, entire to crenate, often 

 undulate, folded, and granulate; apothecia small to middle-sized, 0.5-1 mm. across, 

 immersed usually 1 in each lobe, the disk concave to slightly convex, reddish, the 

 algoid exciple becoming crenulate or lobulate; hypothecium sometimes tinged with 

 umber; spores oblong-ellipsoid, 3-septate transversely and 1-septate longitudinally, 



On rocks, Santa Monica Range, California. The material is doubtfully re- 

 ferred to this species. 



