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

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name	Amanita yucatanensis
name status	nomen acceptum
author	Guzmán
english name	"Yucatán Ringless Amanita"
cap	The cap of A. yucatanensis is 25^± mm wide, convex to near planar, smooth, dry, and has a striate margin. It is white to pale yellowish. The flesh is white. The volva is absent or is present as scattered irregularly shaped, whitish, thin, flat patches.
gills	The gills are narrowly adnate, white to whitish rose, drying pale orange-brown, with fimbriate edges. The short gills are truncate and unevenly distributed.
stem	The stem is 12^± (?) × 5^± mm, narrowing markedly upward, floccose-scaly below, pruinose above, and exannulate. The volva is a white, delicate, membranous sac.
spores	The spores measure (7.8-) 9.5 - 13.0 (-14.2) × (7.0-) 7.5 - 9.5 (-11.8) µm and are inamyloid and broadly ellipsoid to ellipsoid (occasionally subglobose). Clamps are sometimes present at bases of basidia; they are occasionally rather small and somewhat difficult to locate in some sections.
discussion	Amanita yucatanensis was originally described from the state of Yucatán, Mexico in "secondary, perennial tropical rain forest." It is still known only from the original collections cited by Guzmán. According to current understanding of systematics of Amanita section Vaginatae, A. yucatanensis seems to be a rather isolated neotropical taxon. Perhaps, the closest relationship is with the Mediterranean group of taxa related to A. mairei Foley.—R. E. Tulloss
brief editors	RET

name

Amanita yucatanensis

author

Guzmán. 1982. Mycotaxon 16: 255.

name status

nomen acceptum

english name

"Yucatán Ringless Amanita"

MycoBank nos.

109594

GenBank nos.

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accession	locus	voucher	source



No data available in table

holotypes

ENCB; isotype, XAL

type studies

Tulloss. 1994. Mycotaxon 52: 383, figs. 48-49.

selected illustrations

Guzmán. 1983. Biótica 8: 91, fig. 9.

intro

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

The field may contain magenta text representing a type study or a study of original material 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.

Macroscopic data is from the protolog of the present species and Tulloss' examination of the isotype. Microscopic data is from (Tulloss 1994).

pileus

Tulloss (1994): 25^± mm wide, convex to near planar, smooth, dry, white to pale yellowish; context white; margin striate; universal veil absent or as scattered irregularly shaped, whitish, thin, flat patches; pileipellis easily peeling in exsiccatum.

lamellae

Tulloss (1994): narrowly adnate, white to whitish rose, drying pale orange-brown (more yellow than 7.5YR 7/6 and close to 5B5), with fimbriate edges (remaining pale in exsiccatum); lamellulae truncate, unevenly distributed.

stipe

Tulloss (1994): 12^±(?) × 5^± mm, narrowing markedly upward, floccose-scaly below, pruinose above; context not recorded; exannulate; universal veil as membranous saccate volva, white, delicate.

odor/taste

Tulloss (1994): Odorless. Taste not recorded.

macrochemical
tests

Tulloss (1994): none recorded.

pileipellis

Tulloss (1994): 20 - 40 µm thick, extensively gelatinizing at the surface; filamentous, undifferentiated hyphae 1.5 - 4.5 µm wide, subradially oriented, interwoven, densely packed, more yellow brown than adjacent context; refractive hyphae 2.5 - 7.0 µm wide, branching, locally common, sometimes descending into pileus context.

pileus context

Tulloss (1994): filamentous, undifferentiated hyphae 2.2 - 12.5 µm wide, loosely interwoven, branching, often constricted at septa, with some terminal segments narrowly clavate; acrophysalides thin-walled, broadly clavate to ovoid to ellipsoid to oblong to subcylindric, up to 98 × 36 µm; refractive hyphae 2.8 - 7.8 µm wide, branching, common.

lamella trama

Tulloss (1994): bilateral, in some sections obscurely so; w_cs = 50* µm; in some sections dominated by a densely tangled central stratum, imperfectly rehydrating; filamentous, undifferentiated hyphae 2.0 - 7.5 µm wide, subparallel to hymenial surface, sometimes obscuring both inflated intercalary cells and divergent elements, with inflated intercalary segments ellipsoid to subcylindric, up to 42 × 23 µm; apparently terminal, inflated cells resulting from sectioning, with major axis parallel to hymenial surfaces or diverging (as result of sectioning and mounting) at angles up to 45°; vascular hyphae not observed.

subhymenium

Tulloss (1994): w_st-near = 5^± µm; w_st-far = 35^± µm; branching structure dominated by filamentous, undifferentiated hyphae, although with small inflated cells rather plentiful in some regions; basidia arising from small ovoid to subglobose cells and from uninflated or slightly inflated hyphal segments; filamentous, undifferentiated hyphae present running subparallel to hymenial surface near bases of longer basidia. [Note: This description suggests that the material was imperfectly rehydrating.]

basidia

Tulloss (1994): 54 - 70 × 9.0 - 17.0 µm, thin-walled, 4-, or occasionally 2-sterigmate; clamps present, occasionally rather small and somewhat difficult to locate in some sections.

universal veil

Tulloss (1994): On pileus: absent. At stipe base, exterior surface: surface layer with thickness of only one or two hyphal diameters; filamentous, undifferentiated hyphae 1.0 - 6.0 µm wide, dominating, loosely woven, often in fascicles, many sublongitudinally oriented, partially gelatinized; inflated cells uncommon, nearly fully gelatinized, having same form as those of interior; refractive hyphae 2.8 - 6.5 µm wide, lacking a common orientation, sometimes included in fascicles. At stipe base, interior: filamentous, undifferentiated hyphae 1.5 - 10.2 µm wide, dominating, sometimes with very narrowly fusiform intercalary segments, branching, loosely interwoven, constricted at septa, commonly with irregular, flat plaques less than 0.5 µm thick on surface; inflated cells clavate to narrowly clavate to ventricose, terminal, thin-walled or with walls slightly thickened, at times with exterior wall having small surface plaques as in hyphae (only seen on thin-walled cells or on thin-walled parts of cell surfaces), up to 79 × 39 µm; vascular hyphae not observed. At stipe base, inner surface: filamentous, undifferentiated hyphae in fascicles, partially gelatinized, fragmented, occasional; inflated cells slightly narrower on average than in interior; otherwise, like interior.

stipe context

Tulloss (1994): longitudinally acrophysalidic; filamentous, undifferentiated hyphae 1.4 - 10.5 µm wide, plentiful, branching; acrophysalides up to 186 × 39 µm, thin-walled; refractive hyphae 0.7 - 8.8 µm wide, especially frequent near stipe surface; clamps observed.

partial veil

Tulloss (1994): absent.

lamella edge tissue

sterile.

basidiospores

send to graphing tool

Tulloss (1994): [40/1/1] (7.8-) 9.5 - 13.0 (-14.2) × (7.0-) 7.5 - 9.5 (-11.8) µm, (L = 11.6 µm; W = 8.7 µm; Q = (1.11-) 1.17 - 1.44 (-1.53); Q = 1.33), hyaline, colorless, smooth, thin-walled, inamyloid, broadly ellipsoid to ellipsoid, occasionally subglobose, dominantly adaxially flattened, sometimes expanded in middle, often expanded at one end; apiculus sublateral, infrequently lateral, cylindric; context dominantly monoguttulate with a few small granules; color in deposit not recorded.

ecology

Tulloss (1994): Solitary on soil. In secondary, perennial, tropical rain forest.

material examined

Tulloss (1994): MÉXICO: QUINTANA ROO—Road to Vallarta, ca. crossing from Puerto Morelos to Tulum Road, 10.xi.1981 G. Guzmán 21044 (holotype, ENCB n.v.; isotype, XAL).

discussion

Tulloss (1994): The length of the stipe given in the protolog must be in error. The isotype specimen I examined has a very thin stipe exceeding the length reported for the fresh material.

The exterior decoration of cell walls in the universal veil is limited to cases in which the walls otherwise are not thickened. This suggests that the cells have one or more outer layers that rupture in a roughly areolate manner thus giving rise to the patches observed—superimposed on a thin, innermost, tegumentary layer.

As in the case of A. dunicola, a comparison to A. argentea, A. huijsmanii, and A. supravolvata is warranted. The pilei of these taxa are shades of gray or brown. Their universal veil, when it is left on the pileus, takes the form of a rather thick, white patch over the disc. The margins of their pilei are markedly striate. The pileipellis in A. argentea and A. huijsmanii is thicker than in A. yucatanensis and exhibits a criss-cross pattern of somewhat refractive elements. Surface plaques are lacking on all elements of the anatomy of the European taxa. Amanita supravolvata lacks divergent, terminal, inflated cells in the lamella trama and lacks hyphae of the trama running parallel to the central stratum close to the bases of longer basidia.

Comparison to A. dunicola is provided in the discussion following the description of that species.

citations

—R. E. Tulloss

editors

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name	Amanita yucatanensis
name status	nomen acceptum
author	Guzmán
english name	"Yucatán Ringless Amanita"

name	Amanita yucatanensis
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name	Amanita yucatanensis
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Spore data for collections
provisionally identified as: Amanita yucatanensis Guzmán

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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