152 28. COLLEMACEAE [101. Lempholemma 



28. COLLEMACEAE 



Thallus of septate, branching hyphae, ramifying through the algal host colony, 

 giving the appearance of a foliose or fruticose structure, closely adhering to the 

 substratum or attached by rhizoids, the cortex plectenchymatous or of inter- 

 woven hyphae; apothecia round, immersed to superficial, with a proper or thal- 

 loid exciple. 



The algal host is Nostoc. 



A. Reproduction by internal spermatia 104. Collemodes 



A. Reproduction by external spermatia 



B. Spores non-septate 101. Lempholemma 



B. Spores septate 



C. Spores transversely 1-several-septate 102. Synechoblastus 



C. Spores transversely and longitudinally septate 



D. Cortex of interwoven hyphae 103. Collema 



D. Cortex plectenchymatous 105. Leptogitjm 



101. Lempholemma Koerb., Syst. Lich. 400. 1855. 



Transforming the algal colony into small to middle-sized, irregular, lobed or 

 branched, smooth to rough body, the thallus wholly mycelial, imbedded in the host 

 and attached to the substratum by rhizoids; apothecia immersed to adnate, minute 

 to small, sometimes lateral or terminal on the lobes or branches, the disk concave 

 to flat or convex, the algoid exciple thin to thick; hypothecium hyaline; hymenium 

 hyaline or brownish above; paraphyses unbranched, slender; asci clavate, rarely 

 curved or twisted; spores 8, hyaline, spherical to ovoid or ellipsoid, non-septate. 



The algal host is Nostoc. 



A. Thallus foliose to somewhat erect, lobed or 

 cushion-like; spores oblong to ovoid 



B. Thallus small to middle-sized, lobed; spores 8-16 X 7-9 n . 2. L myriococcum 

 B. Thallus minute to small, cushion-like; spores 16-25 X 7-9 n . . 3. L. umbella 



A. Thallus subf ruticose ; spores spherical to ovoid, 15-20 /a across . . 1. L.cladodes 



1. Lempholemma cladodes (Tuck.) Zahlbr., Cat. Lich. Univ. 3:23. 1924. 



Collema cladodes Tuck., Gen. Lich. 89. 1872. Physma cladodes (Tuck.) Zahlbr. 



Transforming the algal colony into a small, tough, subfruticose, blackish green, 

 branched body, the branches longitudinally striate and marginally stellate; apothe- 

 cia minute, 0.2-0.4 mm. across, borne terminally or laterally on the branches, the 

 disk strongly convex, black; spores spherical, varying toward ovoid, 15-20 /x across. 



On calcareous rocks, near Trenton Falls, New York. 



2. Lempholemma myriococcum (Ach.) T. Fries, Nov. Act. Reg. Soc. Sci. Upsal. 



III. 3:381. 1861. 

 Lichen myriococcus Ach., Lich. Suec. 127. 1798. Collema myriococcum Ach. 



Physma myriococcum (Ach.) Koerb. 

 Transforming the algal colony into a small to middle-sized, blackish, round to 

 irregular, closely attached, irregularly flexuously and complicatedly lobed body, the 

 lobes warty, with more or less irregular margins; apothecia minute, 0.1-0.3 mm. 

 across, partly immersed, crowded, the disk concave, pale to darker brown, the 

 exciple thin, colored like the thallus; spores ovoid to ovoid-ellipsoid, 8-16 X 7—9 /x. 

 Over mosses on calcareous rocks, New York, New Jersey, and Alabama. 



3. Lempholemma umbella (Tuck.) Zahlbr., Cat. Lich. Univ. 3:22. 1924. 



Omphalaria umbella Tuck., in Nyl., Syn. Lich. 1:105, 106. 1858. Collema 

 umbella (Tuck.) Nyl. 



Transforming the algal colony into a minute to small, thick, rigid, cushion-like, 

 marginally crenulate and lobulate, minutely granulose, greenish brown to blacken- 

 ing body; below brownish to darker; apothecia minute to small, 0.1-0.3 mm. across, 

 slightly immersed to adnate, the disk becoming flat, reddish brown to brown, the 



