115. Sticta] 31. STICTACEAE 179 



algal layer, medullary layer of loosely interwoven hyphae, and a thin, well- 

 developed, plectenchymatous lower cortex, continuous or broken by cyphellae; 

 apothecia small to middle-sized or large, adnate, sessile or substipitate, marginal, 

 submarginal, or scattered, the disk concave to flat or more or less convex, the exciple 

 colored like the thallus, irregular, sometimes disappearing; hypothecium hyaline 

 to brownish; hymenium hyaline to brownish above; paraphyses unbranched; asci 

 clavate to ovate-clavate; spores 8, hyaline to rarely brown, oblong-ovoid, fusiform 

 or acicular, 1-3-septate. 



The algal host is Protococcus or Nostoc. 



A. Thallus without cyphellae or bare spots below 



B. Thallus clothed below with a spongy nap of short rhizoids . . 1. S. amplissima 

 B. Thallus bearing few to many rhizoids 



C. Lobes small, round; spores 1-septate, 26^44 X 9-11 m ... 2. S.herbacea 

 C. Lobes somewhat elongated; spores 3-septate, 48-70 X 3-5 /* . . 3. S. erosa 

 A. Thallus with either cyphellae or bare spots below 

 B. Thallus with bare spots below 

 C. Thallus reticulately ribbed 



D. Sorediate or isidioid along the reticulations and margins; 



spores 18-33 X 5.5-9 /x 4. S. pulmonaria 



D Not sorediate or isidioid ; spores 42-60 X 6-9 ^ . • • • 6. S. oregana 

 C. Thallus more or less pitted but not ribbed 



D. Thallus rather closely attached, brownish yellow to 



olive-green or brown 5. S. limta 



D. Thallus rather loosely attached, greenish gray to ashy 

 and yellowish or brownish 



E. Soredia along the margins 8. S. verrucosa 



E. Soredia scattered 7. S. Hallii 



B. Thallus with cyphellae below 

 C. Cyphellae sorediate 

 D. Cyphellae yellowish 



E. Thallus greenish gray to brownish red or finally 



rose-red, soredia marginal 9. S. aurata 



E. Thallus greenish gray to brownish or greenish brown, 



soredia usuallv scattered 10. S. crocata 



D. Cyphellae whitish H. S. anthraspis 



C. Cyphellae bare 



D. Thallus more or less covered with minute blackish 



granules 13 - S. fuliginosa 



D. Thallus not granulose 

 E. Thallus bearing isidia 



F. Isidia scattered 1*. S. sylvatica 



F. Isidia usually marginal 



G. Lobes broad; spores 1-3-septate 12. S. Weigelu 



G. Lobes elongated, narrow, more or less divided; 



spores 3-septate IS. S. quercizans 



E. Thallus bearing soredia 16. S. limbata 



1. Sticta amplissima (Scop.) Rabh., Deutsch. Krypt. Fl. 2:64. 1845. 



Lichen amplissimus Scop., Fl. Cam. ed. 2. 2:386. 1772. Lobaria amplissima 

 (Scop.) Forss. S.glomulijera (Lightf.) Del. 



Thallus middle-sized to large, rather closely attached to the substratum, smooth 

 to becoming more or less wrinkled, greenish gray to ashy or brownish, the lobes 

 somewhat elongated, narrow to wider, sometimes more or less imbricated, with 

 sinuate, or obscurely crenate margins; commonly lighter below, clothed with a 

 spongy nap of short rhizoids interspersed with few longer ones or rarely bearing 

 only long rhizoids; apothecia middle-sized, 1-3 mm. across, subsessile, scattered, 

 the disk concave to flat, chestnut-brown, the exciple thin, becoming crenulate; 

 spores acicular, 3-septate, 30-65 X 4.5-8 /a. 



On trees, from Maine to Florida, and westward to Texas and Minnesota. 



