North American species of Mycena.

164 NORTH AMERICAN SPECIES OF MYCENA

3. Pileus smoky yellow; pleurocystidia absent......... 71. M. flavifolia
3. Pileus yellow; pleurocystidia abundant........... 7. M. carolinensis
4. Pileus pale yellow to cadmium yellow........................... 5
4. Pileus reddish to reddish yellow, at least when young............. 6
5. Growing singly from buried nuts and acorns or from hulls of these
fruits...................................... 75. M. luteopallens
5. Growing gregarious on humus, usually under conifers in mountains
(a) Spores 7-9 u long........................... 73. M. flavoalba
(b) Spores 5-6 A long............ 74. M. flavoalba var. microspora
6. Pleurocystidia absent or rare and usually occurring near gill edge.. 7
6. Pleurocystidia abundant and conspicuous........................ 8
7. Spores 5-6.5 X 5-6 u (4-spored)................. 76. M. leptophylla
7. Spores 7-9 X 5-6,g (4-spored).................. 77. M. roseipallens
8. Pileus scarlet when fresh, fading to orange; cystidia pointed
80. M. adonis
8. Pileus as above; cystidia obtuse..................... 78. M. fusipes
8. Pileus orange when young.................... 79. M. aurantiidisca
9. Cheilocystidia roughened (but smooth type may also be present)... 10
9. Cheilocystidia smooth and fusoid-ventricose..................... 11
10. Pleurocystidia absent............................ 84. M. monticola
10. Pleurocystidia present (fusoid-ventricose)....... 83. M. subincarnata
11. Gregarious to subcespitose on leaf mold under hardwoods, occasionally on bark of trees or on debris............. 81. M. roseocandida
11. Gregarious to scattered on beds of moss, particularly sphagnum, and
on needle carpets under conifers (a form of M. flavoalba with a
pinkish disc keys out here also)............ 82. M. amabilissima
71. MYCENA FLAVIFOLIA Peck
Bull. New York State Mus., 167: 28. 1913
Prunulus flavifolius Murrill, North Am. Flora, 9: 324. 1916.
Illustrations: Text fig. 15, nos. 9, 12 (p. 160).
"Pileus thin, slightly submembranaceous, conic or convex, sulcate
striate, somewhat plicate-crenate on the margin, glabrous, pale
smoky yellow becoming pale pinkish brown or subalutaceous in drying, sometimes slightly umbonate; lamellae thin, close, broad at the
outer extremity, narrowed toward the stem, pale yellow, becoming
pallid in drying; stem slender, equal, glabrous, hollow, chestnut
colored; spores ellipsoid or subovoid, 6-8 X 4-5.