Amanita humboldtii - Amanitaceae.org - Taxonomy and Morphology of Amanita and Limacella

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name	Amanita humboldtii
name status	nomen acceptum
author	Singer
english name	"Humboldt's Ringless Amanita"
cap	The data in this description is almost entirely dependent on the protolog and a study of the type. The cap of Amanita humboldtii is usually free of volval remnants, 35 - 60 mm wide, subumbonate to depressed, with a strongly striate margin; it is dull fuscous brown or ranging from dark orange-brown to fuligineous in the center and orange-brown to medium dark brown in the outer part. [Note: the description seems to mix the present species with A. fuligineodisca Tulloss, Ovrebo & Halling. The reader should assume that the color of A. humboldtii is "dull fuscous brown."]
gills	Gills are free, close, white in side view, and about 5 mm broad, sometimes marginate and then having edge white or concolorous with pileus on the portion of the gills closest to the cap margin. There is no information on the short gills.
stem	The stem is 60 - 180 × 6 - 11 mm, entirely white or white on the lower half and pale orangish tan on the upper half, exannulate, and has a membranous sack-like volva at the base. Singer describes the volval sac as (for example) 20 × 12 mm high. The volval sack may be white, cinnamon, or orange; it is largely free from the stem.
spores	The spores measure (10.2-) 11.0 - 14.0 (-15.5) × (9.0-) 9.8 - 13.0 (-13.3) µm and are inamyloid, globose to subglobose or (infrequently) broadly ellipsoid. Clamps are rare or absent at bases of basidia.
discussion	Amanita humboldtii is known from Andean Colombia, occurring with oak. Apparently, it is not frequently collected. One collection that might be attributable to this species has been sent me from Costa Rica. I have never seen fresh material of this species. Judging from Singer's original description, the species is apparently quite similar macroscopically to A. fuligineodisca Tulloss, Ovrebo & Halling macroscopically, but the two taxa can be distinguished microscopically. Based on the limited number of available collections known, A. humboldtii has larger spores and more layers of cells in its subhymenium. The closest relative of A. humboldtii may be A. pekeoides G. S. Ridl. of New Zealand.—R. E. Tulloss
brief editors	RET

name

Amanita humboldtii

author

Singer. 1963. Mycopathol. Mycol. Appl. 20: 241, figs. 8-10.

name status

nomen acceptum

english name

"Humboldt's Ringless Amanita"

etymology

genitive of a Latinized name; hence, "Humboldt's" or "of Humboldt"

MycoBank nos.

326098

GenBank nos.

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accession	locus	voucher	source



No data available in table

holotypes

BAFC

revisions

Tulloss et al. (1992) Mem. New York Bot. Gard. 66: 16, figs. 8-10.

intro

The following text may make multiple use of each data field.

The field may contain magenta text representing a type study by Tulloss.

The same field may also contain black text, which will represent a revision of the species by Tulloss. Paragraphs of black text will be labeled if further subdivision of this text is appropriate.

Olive text indicates a specimen that has not been thoroughly examined (for example, for microscopic details) and marks other places in the text where data is missing or uncertain.

The following is based upon original research by R. E. Tulloss.

pileus

37 - 60 mm diam., “cochin” (MP) (dull fuscous brown) or 6D-F8 in disk and 6C7 or 6E6 toward margin, planoconvex, subumbonate to depressed, slightly viscid when wet; context white, unchanging on exposure, 3.5^± mm thick; margin pectinate-sulcate, decurved; universal veil absent.

lamellae

free, close, white, drying a pale slightly sordid tan or brown (6D-E4), 5^± mm broad, with fimbriate edge that may be white or (at least near pileus margin) marginate (concolorous with pileus surface).

stipe

63 - 180 × 6 - 11 mm, entirely white or somewhat darker than 5B3 in upper half and otherwise white, firm, narrowing upward, glabrous to fibrillose; context white, solid or becoming hollow especially in lower portion; exannulate; universal veil as free volval sac, “caramel” (MP) (cinnamon to orange) or whitish, membranous, 20^± × 12^± mm.

odor/taste

Odorless. Taste not recorded.

macrochemical
tests

none recorded.

pileipellis

20 - 56 µm thick; slightly gelatinizing subradially arranged interwoven filamentous undifferentiated hyphae with a pale yellowish brown intracellular pigment partially soluble in KOH, 1.2 - 7.8 µm wide; vascular hyphae 1.8 - 11.0 µm wide, branching, relatively common.

pileus context

filamentous undifferentiated hyphae loosely interwoven to tangled, sometimes in fascicles, 1.2 - 12.8 µm wide, with some intercalary segments slightly inflated to 14.0 µm wide; acrophysalides with walls thin or up to 0.5 µm thick, slenderly clavate to subventricose to ventricose (to 92 × 27 µm) to broadly clavate (to 71 × 42 µm) to ellipsoid to subglobose or pyriform (to 63 × 51 µm); vascular hyphae 1.5 - 10.5 µm wide, branching, common.

lamella trama

bilateral; w^cs = 50 - 55 µm; central stratum very distinct; subhymenial base with angle of divergence 45° - 90°; filamentous, undifferentiated hyphae 2.1 - 11.5 µm wide, branching; inflated cells up to 34 × 20 µm, clavate to ventricose to ellipsoid, diverging at angles cited above; vascular hyphae 2.2 - 6.3 µm wide.

subhymenium

w_st-near = 60 - 70 µm; w_st-far = 85 - 105 µm; 4 to 5 inflated cells deep, with basidia arising from uninflated to slightly inflated hyphal segments or (predominantly) from inflated cells of varying size (up to 27 × 25 µm, clavate to broadly clavate to ovoid to ellipsoid to subpyriform to subglobose to globose, arranged in branching chains arising in central stratum).

basidia

49 - 78 × 11.5 - 24 µm, thin-walled, clavate, dominantly 4-, occasionally 2-sterigmate; sterigmata to 2.0 µm broad at base; clamps rare.

universal veil

At stipe base, exterior surface: with very thin layer of filamentous, undifferentiated hyphae 2.2 - 12.6 µm wide, in disorderly loose mat, gelatinized, also occasionally in longitudinally oriented fascicles, dominant; inflated cells up to 39 × 33 µm, gelatinizing; vascular hyphae scarce or absent. At stipe base, interior: filamentous, undifferentiated hyphae 1.4 - 15.8 µm wide, rather densely tangled/interwoven, branching, plentiful, locally dominant, at times in fascicles, somewhat gelatinizing; inflated cells more plentiful than at surfaces, locally dominant, subpyriform to ellipsoid to ovoid to broadly clavate to ellipsoid, thin-walled, to 65 × 54 µm; vascular hyphae 2.8 - 7.0 µm wide. On stipe base, inner surface: as rather thin layer, absent in some specimens or in limited areas of volval limb of other specimens; filamentous, undifferentiated hyphae 1.5 - 8.0 µm wide, branching, longitudinally arranged, partially gelatinizing; inflated cells scattered, collapsing, gelatinizing, up to 52 × 34 µm; vascular hyphae 4.2 - 17.0 µm wide, partially gelatinizing, sublongitudinally arranged to disordered. On pileus: absent.

stipe context

longitudinally acrophysalidic; filamentous, undifferentiated hyphae 2.0 - 10.5 µm wide; acrophysalides narrowly clavate to narrowly subventricose, up to 290 × 39 µm, with walls thin or up to 0.8 µm thick; vascular hyphae 1.2 - 13.3 µm wide, occasionally tangled in knots.

basidiospores

send to graphing tool

type study, RET: [20/1/1] (10.4-) 11.9 - 14.4 (-15.5) &time; (9.7-) 10.5 - 13.3 μm, (L = 12.8 μm; W = 11.7 μm; Q = 1.0 - 1.25 (-1.28); Q = 1.09), hyaline, colorless, smooth, thin-walled, inamyloid, globose to subglobose to broadly ellipsoid, often adaxially flattened; apiculus sublateral, cylindric, rather prominent, proportionately broad; contents guttulate; color in deposit not recorded.

composite of all RET spore data: [77/2/2] (10.2-) 11.0 - 14.0 (-15.5) × (9.0-) 9.8 - 13.0 ( 13.3) µm, (L = 12.5 - 12.8 µm; L’ = 12.7 µm; W = 11.4 - 11.9 µm; W’ = 11.7 µm; Q = (1.0-) 1.01 - 1.20 (-1.28); Q = 1.08 - 1.09; Q’ = 1.09), inamyloid, hyaline, smooth, globose to subglobose to broadly ellipsoid; contents guttulate to granular, in Melzer’s reagent coagulating and sticking to spore walls; apiculus sublateral, often broad and prominent, cylindrical; color in deposit unknown.

ecology

Solitary. At 1700 - 2700 m elev. In Quercus humboldtii forests.

material examined

COLOMBIA: CUNDINAMARCA—Mpio. Pacho - Los Robledales [misspelled in protologue] above Pacho, 26.vii.1960 R. Singer B3527 (BAFC 31.975, holotype); Cerra de Las Mercedes, rd. btwn. Bogotá and La Mesa, s.d. G. Guzmán 4602 (ENCB; COL). NARIÑO—Mpio. Pasto - vereda “La Josefina,” km 17, rd. from Pasto to Chachagüí, 20.xi.1988 A. E. Franco-M. 190 (NY; PSO).

discussion

RET has enhanced the macroscopic information in the protologue with data from Singer’s original notes (in F) on the holotype collection as well as with data from the recent collections. The data on anatomy includes that from a complete anatomical review of the holotype. For comparison to A. fuligineodisca see the discussion of that species, directly above. Apparently A. humboldtii is a rather rare species.

Amanita humboldtii is a small brownish mushroom with a striate pileus margin, exannulate stipe, and a membranous whitish to cinnamon colored volval sac. In the present state of knowledge, it is distinguished from A. fuligineodisca based on microscopic characters.

The specimen Franco-M. 192 (NY; PSO) is probably assignable to this taxon; while it is immature and lacks spores, its anatomy is identical to that of Franco-M. 190 which was collected in the same locality.

citations

—R. E. Tulloss

editors

RET

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name	Amanita humboldtii
name status	nomen acceptum
author	Singer
english name	"Humboldt's Ringless Amanita"

name	Amanita humboldtii
bottom links	[ Keys & Checklists ]

name	Amanita humboldtii
bottom links	[ Keys & Checklists ]

Spore data for collections
provisionally identified as: Amanita humboldtii Singer

Spore data sets and their composite

Each spore data set is intended to comprise a set of measurements from a single specimen made by a single observer; and explanations prepared for this site talk about specimen-observer pairs associated with each data set. Combining more data into a single data set is non-optimal because it obscures observer differences (which may be valuable for instructional purposes, for example) and may obscure instances in which a single collection inadvertently contains a mixture of taxa.

basidiospore definition

Spore Measurements by Collection

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