64 7. STRIGULACEAE [ 29. Pyrenastrum 



29. Pyrenastrum Eschw., Syst. Lich. 16. 1824. 



Thallus crustose, thin, smooth to rough, partly within the substratum, devoid 

 of differentiation into layers or showing a poorly developed upper cortex of coher- 

 ent hyphae; perithecia minute to small, immersed, clustered and more or less 

 united, the wall complete, the superficial portion more or less convex, the ostiole 

 minute; hypothecium brownish; hymenium hyaline or brownish above; paraphyses 

 branched and interwoven; asci clavate; spores 4-8, brownish to brown, ellipsoid 

 to oblong-ellipSoid, 3-7-septate, the cells lenticular. 



The algal host is Trentepohlia. 



1. Pyrenastrum pyrenastraeum (Nyl.) Zahlbr., Cat. Lich. Univ. 1:520. 1922. 



Astrothelium pyrenastrum Nyl., Lich. Jap. 109, 110. 1890. 



Superficial thallus thin, yellowish brown, smooth to becoming slightly rough 

 and cracked; perithecia minute to small, 0.2-0.6 mm. across, partly immersed, 

 the whitish ostiole protruding, the superficial portion convex, black; tinged brown- 

 ish within; asci cylindrico-clavate ; spores 8, ellipsoid, tinged brown, 3-septate, 

 10-18 X 5-6.5 ix. 



On trees, near Jacksonville, Florida. 



30. Parmentaria Fee, Essai Crypt. 70. 1824. 



Thallus crustose, thin, smooth to rough, partly within the substratum, devoid 

 of differentiation into layers, or rarely showing a poorly developed upper cortex 

 of coherent hyphae; perithecia minute to small, 1-several immersed in each thalloid 

 elevation, radially arranged, the wall complete, black, the ostiole minute, con- 

 verging, canal-like; hypothecium brownish; hymenium hyaline or brownish above; 

 paraphyses branched and netlike interwoven; asci clavate; spores 1-8, brown, 

 ovoid to ovoid-ellipsoid or oblong, transversely and longitudinally septate. 



The algal host is Trentepohlia. 



A. Spores 30-36^ in length 1- P- astroidea 



A. Spores 38-76 /x in length 2. P. Raveneln 



1. Parmentaria astroidea Fee, Essai Crypt. 70. pi. 1, f. 14. 1824. 



Pyrenastrum gemmeum Tuck. Pyrenastrum americanum Spreng. 



Thallus thin, smooth to wrinkled and slightly warty, greenish gray to straw- 

 colored; perithecia small, 0.3-0.7 mm. across, black, 1-3 or 4 borne in elevated 

 warts of thallus, in groups of 4-6, radially arranged, converging but not meeting, 

 the proper exciple black, the ostioles minute, canal-like; spores 8, ovoid to ovoid- 

 ellipsoid, 5-9-septate transversely and 1-3-septate longitudinally, 30-36 X 8-12 /* 

 (Nyl. says 34^15 X 14-18 fi.) 



On trees, South Carolina and Texas. 



2. Parmentaria Ravenelii (Tuckj Mull. Arg., Flora 68:249, 250. 1885. 



Pyrenastrum Ravenelii Tuck., Am. Journ. Sci. II. 25:429. 1858. 



Thallus thin, smooth to somewhat wrinkled, waxy, greenish to yellowish brown; 

 perithecia small, 0.3-0.6 mm. across, black, flask-shaped, borne in slightly elevated 

 warts of thallus, radially arranged, the proper exciple black, the ostioles minute, 

 canal-like, convergent, brownish black with pale mouth; spores 8, ellipsoid, 7-9- 

 septate transversely and 4-5-septate longitudinally, 38-76 X 16-27 /x. 



On trees, Florida and Texas. 



7. STRIGULACEAE 



Thallus crustose, devoid of differentiation into layers, attached to the sub- 

 stratum by hyphal rhizoids; perithecia more or less immersed, single or rarely 

 clustered, the ostiole terminal. 



The algal hosts are Cephaleurus, Heterothallus, Phycopeltis, and Phyllactidium. 

 The family is limited to the tropics and subtropics and confined to leaves. 



