The North American Species of Pholiota
112. Pholiota limonella (Pk.) Saccardo, Syll. Fung. 5: 753. 1887.
Agaricus (Pholiota) limonellus Peck, New York State Mus. Ann. Rept. 31: 33. 1879.
Hypodendrum limonellum (Pk.) Murrill, Mycologia 4: 261. 1912.
Illustrations: Text figs. 237-239.
Pileus 2.5-5 cm broad, convex or nearly plane, sometimes umbonate, lemon-yellow when fresh, with scattered reflexed or suberect fibrillose reddish or tawny scales, viscid. Context thin, yellow.
Lamellae sinuate-adnate or slightly adnexed, whitish, becoming ferruginous, narrow (2-4 mm broad), close.
Stipe 3-7 cm long, 3-5 mm thick, pallid or yellowish, with scattered, recurved yellow scales, smooth above the annulus, equal. Veil forming a floccose, evanescent yellow annulus.
Spores 6-7.5 x 4-5 µ, smooth, apical pore distinct causing apex to appear subtruncate in some; shape in face view ovate to elliptic, in profile obscurely bean-shaped to obscurely inequilateral, color in KOH dull tawny to ochraceous tawny, in Melzer's reagent more ochraceous on standing; wall about 0.3 µ thick.
Basidia 4-spored, 18-24 x 6-7.5 µ at apex, about 2 µ in the pedicel, hyaline in KOH, nearly so in Melzer's reagent. Pleurocystidia 23-40 x 7-12 µ, long-pedicellate and clavate-mucronate to subclavate above, with a hyaline refractive inclusion as revived in KOH or containing evenly ochraceous to rusty brown homogeneous material, smooth, thin-walled. Cheilocystidia 23-30 x 5-9 µ, clavate, fusoid, or subcylindric, content usually ochraceous, thin-walled, smooth. Caulocystidia rare, resembling the cheilocystidia.
Gill trama of a central area of interwoven hyaline hyphae reddish orange in Melzer's reagent as revived, walls thin and smooth; subhymenium of gelatinous narrow hyphae. Pileus cuticle a gelatinous pellicle of hyphae 2-4 µ diam. with colloidal content and red in Melzer's but fading to paler on standing; below this a region of wider (5-12 µ) hyphae with colloidal content dark red in Melzer's fading to orange-reddish. Clamp connections present.
Habit, Habitat, and Distribution: On prostrate beech trunks, New York, September. Type studied.
Observations: Our data are all taken from the type or original description. P. limonella is distinguished from P. flammans by larger spores. It is very close to P. squarroso-adiposa, so close we thought for a time the two were identical, and they may well be. However, the Melzer's reaction of the pileus context appears to separate them. In addition, by comparison, the basidiocarps of P. limonella are more delicate. The figure (pl. 45) in Icones Farlowianae is very likely some other species. Pholiota subsquarrosa Fr. sensu Soehner (1922) is very close to this species but has bright yellow gills when young. Fries' illustration shows a species very close to P. limonella but again the gills are yellow when young.