1925] 



BURT THE THELEPHORACEAE OF NORTH AMERICA. XIV 327 



95. P. citrinella (B. & C.) Burt, n. comb. 



Corticium citrinellum Berkeley & Curtis, Linn. Soc. Bot. Jour. 

 10: 336. 1868; Sacc. Syll. Fung. 6: 616. 1888; Massee, Linn. 

 Soc. Bot. Jour. 27: 147. 1890. 



Type: in Curtis Herb, and probably in Kew Herb. 



Fructifications effused, thin, tender, small pieces separable 

 when moistened, barium-yellow, cracked and showing a byssoid, 

 barium-yellow subiculum, the margin thinning out, sometimes 

 with barium-yellow mycelial strands; in section 120-300 y. thick, 

 barely barium-yellow when but slightly magnified but not per- 

 ceptibly colored under high magnification and wholly bleached 

 by treatment with potassium hydrate solution, 2-layered, with 

 the broader layer next to the substratum and composed of loosely 

 interwoven hyphae 2J^-3 y. in diameter under the incrustation 

 of scattered, coarse granules, not nodose-septate, and with the 

 hymenial layer 90 (x thick, compact; no gloeocystidia; wholly 

 immersed cystidia few, incrusted, 15 x9[a; protruding cystidia 

 hair-like, short, 3-4 J^ ^ m diameter, protruding up to 12 [l; 

 spores hyaline, even, 3-4 X 2-3 \l. 



Fructifications 1-3 cm. long, J^-l cm. wide. 



On bark of logwood limb on the ground. West Indies. October 

 to March. 



P. citrinella belongs in the group of species with P. sulphurina, 

 P. limonia, P. Burtii, and P. subiculosa, and appears distinct from 

 each of these when specimens are compared with one another. 

 It has priority over all the others as a species. Its distinguishing 

 combination of characters is barium-yellow color, cracked hy- 

 menium showing subiculum of the same color, color bleached by 

 treatment with potassium hydrate solution, short cystidia, and 

 occurrence on frondose bark. 



Specimens examined: 

 Cuba: C. Wright, 844, type (in Curtis Herb.); Pinar del Rio 



Province, Earle & Murrill, 381, comm. by N. Y. Bot. Gard. 



Herb.; Santa Clara Province, Earle & Murrill, 4?, comm. by 



N. Y. Bot. Gard. Herb. 

 Jamaica: Hope Gardens, P. S. Earle, 164, comm. by N. Y. Bot. 



Gard. Herb. 



