Rapacea mariae
Rapacea mariae E. Horak 1999, in Horak, Kew bulletin, 789-794 (1999).
Etymology: Rapaceus (Lat.), referring to the rape or turnip-like shape (as e.g. Beta sp.) of the stipe; mariae, named after Mrs Marie Taylor (Auckland) who discovered, painted and recorded the present taxon (as "Cortinarius sp.") for the first time in New Zealand (Taylor 1981).
Diagnosis: Pileus (20 -) 35 - 90 mm, at first hemispherical to convex with strongly incurved or inrolled margin, gradually becoming convex-umbonate or depressed-expanded; pure white, ivory white or egg-shell white, in mature specimens with pale grey tinge over disc, occasionally becoming pale yellow or cream when handled; surface dry, at first smooth, later silky to densely innate-fibrillose, gradually becoming minutely squamulose or scurfy, in young specimens non-striate margin covered with + persistent white fibrillose, attached or appendiculate veil remnants. Lamellae 40 – 70 reaching stipe, lamellulae 3 - 5(- 15), rather crowded, adnexed to broadly adnateemarginate and then decurrent with short tooth, ventricose; off-white to beigeargillaceous with distinctive olive tinge, mustard yellow-brown in mature specimens; edges whitish or concolorous, notched to serrate. Stipe (40 -)50 - 100 x 7 - 12 mm, distinctly swollen-fusoid (- 20 mm at base) or bulbous with tapering rooting base, rarely also slender cylindrical; white; longitudinally innate-fibrillose, dry, below inconspicuous fibrillose cortina with several white subpersisting belts of attached fibrillose to cottony zones of outer veil, solitary or caespitose, base occasionally with white mycelial strands attached to substrate. Context solid white, unchanging, firm. Odour strongly fragrant, sweet, like "bonbon d'anglais", recalls scent of Pyrola sp. Taste mild, not distinctive. Chemical reactions on surface of pileus: KOH, NH3, HC1 AgNO3 - negative; phenol at first negative but spot slowly turning to chocolate brown. Spore print (mustard) yellow-brown with distinctive olive tinge. Basidospores (14 -)15 - 18(- 19) x (8.5 -)9 - 10.5(- 11) µm, broadly amygdaliform (in side view) to limoniform (in dorso-ventral view), yellow-brown (with olive tinge), walls (in water or KOH 4%) smooth to minutely roughened or asperulate, covered (SEM) with low irregularly net-like or crested ornamentation, thick-walled (up to 1.5 µm diam.), germ pore absent, inamyloid (but becoming brown in Melzer's reagent). Basidia (35 -)40 - 50(- 55) x 10 - 14 µm, 4-spored, sterigmata up to 8 pm long. Cheilocystidia (15 -)25 - 65 x 10 - 17 µm, articulate, terminal cells clavate to vesiculose, hyaline membranes thin-walled, forming sterile edges of lamellae. Pleurocystidia absent. Caulocystidia absent. Pileipellis a cutis composed of cylindrical hyphae, 3 - 6 µm diam., terminal cells not differentiated, hyaline smooth membranes non-gelatinised, pigment absent. Suprapellis (subcutis) subregular, composed of hyaline, ovoid to short-cylindrical entangled cells, 10 - 20 µm wide. Oleiferous hyphae scattered. Clamp connectionsp resent at (all) septa of hyphae and hymenial cells. Figure 1 & 2.
Index Fungorum Number: IF459947
Figure 1. Rapacea mariae. SEM micrographs of basidiospores: A, B Mills & Horak 4339; C, D Horak 759, holotype. Scalebar = 2 pm.
Figure 2. Rapacea mariae. A basidiomes (actual size); B basidiospores (x 2000); C basidia (x 1000); D cheilocystidia(x 1000); E basidiomes (actual size). A - D Mills & Horak 4339; E Horak 68-218.
Reference:
Horak, E. (1999). New genera of Agaricales (Basidiomycota). 1. Rapacea gen. nov. Kew bulletin, 789-794.
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