102. Synechoblastus ] 28. COLLEMACEAE 153 



algoid exciple thick, colored like the thallus; hypothecium hyaline to brownish; 

 spores oblong, 16-25 X 7-9/*. 

 On rocks, Alabama and Iowa. 



102. Synechoblastus Trev., Caratt. Gen. Collem. 3. 1853. 



Transforming the algal host colonies into small to large, irregularly lobed, foli- 

 ose bodies, thallus wholly mycelial, imbedded in the host and usually attached to 

 the substratum by hyphal rhizoids; apothecia small to middle-sized, somewhat 

 immersed to adnate or sessile, the disk flat to slightly convex, brownish to brown, 

 the algoid exciple usually present; hypothecium hyaline to brownish; hymenium 

 hyaline to brownish above; paraphyses rarely branched; asci clavate; spores 8, 

 hyaline, 1-several-septate, the cells cylindrical. 



The algal host is Nostoc. 



A. Spores 1-3-septate 



B. Spores constantly 1-septate 

 C. On trees, old wood and soil 



D. Thalloid body of divided or deeply cut lobes 



E. Thalloid body small, lobes palmately divided .... 6. S.texanus 

 E. Thalloid body larger, lobes long and more or less 



branched 7. S. pycnocarpus 



D. Thalloid body of round lobules or stalked 



granules 5. S. coccophorus 



C. On rocks, sometimes with moss 



D. Thalloid lobes narrow, with rough nodular tips . . .3. S.laciniatus 



D. Thalloid lobes wider, with closely wrinkled margins . . 4. S. ohioensis 

 B. Spores 1-3-septate 

 C. On trees and soil 



D. Thalloid body of minute, erect, short branches . . . 8. S. fascicularis 

 D. Thalloid body of narrow, fenestrate lobes . . . . . 10. S. cyrtaspis 



C. On rocks; spores 4-8 in an ascus 12. S. wyomingensis 



A. Spores 3-5- or more-septate 



B. Spores rarely more than 40 fx in length 



C. Thalloid body cushion-like, very small 11. S. microptychius 



C. Thalloid body small to middle-sized, not cushion-like 

 D. Spores rarely less than 25 ix in length 



E. Thalloid body small, lobes narrow, usually short 

 F. Thalloid body densely wrinkled; spores 25-40 



X 2.5-5 /x 13. S. leptaleus 



F. Thalloid body somewhat wrinkled ; spores 



22-34 X 4-7 /x 14. S. ryssoleus 



E. Thalloid body larger, lobes broad and expanded . . . 2. S. rupestris 



D. Spores 17-26 X 6-7.5 fx 9. S. poly carpus 



B. Spores rarely less than 40 fx in length 



C. Thalloid body expanded, lobes broad 1. S.nigrescens 



C. Thalloid body not expanded, lobes narrow 



D. Apothecia 0.4-0.8 mm. across; spores 5-7-septate . . 16. S. leucocarpus 

 D. Apothecia 0.6-2 mm. across, crowded; 



spores 3-5 -septate 15. S.aggregatus 



1. Synechoblastus nigrescens (Huds.) Trev., Caratt. Gen. Collem. 3. 1853. 



Lichen nigrescens Huds., Fl. Angl. 450. 1762. Colletna nigrescens (Huds.) DC. 

 Collema nigrescens var. leucopepla Tuck. S. nigrescens var. leucopeplus 

 (Tuck.) Fink. S. vespertilio (Lightf.) Hepp. 



Transforming the algal colony into a small to middle-sized or larger, closely 

 adnate, somewhat lobed, smooth to closely beset with pustules or radiately ridged, 

 olive-green to greenish black body, the lobes round, short, with entire, slightly as- 

 cending margins; greenish below, marked with depressions; apothecia small to 

 middle-sized, 0.4-1.25 mm. across, sessile, numerous, often crowded toward the 

 center of the thallus, the disk flat to convex, brown or reddish brown or grayish 



