The following is based on the original description (2000).
The cap of Amanita microspora is 30 - 50 mm wide, convex, becoming slightly depressed in age, pure white at first, soon pale yellow to ochre over the center, with a broad, white, striate margin. The cap is viscid when moist with white patches, and the floccose remnants of the volva, unevenly scattered over the center, either easily lost or becoming glued to the surface. The flesh is firm and white.
Gills are free, ventricose, subdistant, white at first, soon becoming pale ochre. The short gills are infrequent.
The stem is 35 - 60 × 3 - 5 mm, equal, white, dry, with a fine granular surface and light yellowish tinted belts at about its midpoint. with an abrupt ovoid basal bulb. The bulb is up to 15 mm wide at the base. The volva remains on the lower stem and top of the bulb are white squamules. A ring is lacking. The flesh is firm and white.
The spores measure 5 - 7 × 4.5 - 6.7 µm and is subglobose to broadly ellipsoid and inamyloid. Clamps are absent at bases of basidia.
This species occurs on sandy soil in coastal dunes with Coccoloba uvifera. In recent years, a growing number of Amanita species have been collected in association
with Coccoloba; among them are Amanita dunicola Guzmán and
A. arenicola O. K. Mill & D. J. Lodge. Additional (probably undescribed) taxa seemingly associated with Coccoloba are currently being revised from countries in or around the Caribbean. The present species was originally described from Puerto Rico.—R. E. Tulloss and L. Possiel
O. K. Mill. in Miller et al. 2000. Mycologia 92: 562, figs. 12-14.
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CFMR; isotype, UPRRP
The following text may make multiple use of each data field.
The field may contain magenta text presenting data from a type study
and/or revision of other original material cited in the protolog of the present taxon.
Macroscopic descriptions in magenta are a combination of data from the protolog and
additional observations made on the exiccata during revision of the cited original
The same field may also contain black text, which is data from a revision of the present
taxon (including non-type material and/or material not cited in the protolog).
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 material is derived from the protolog of the present species.
from protolog: 30 - 50 mm wide, convex becoming slightly depressed in age, pure white at first, soon pale yellow to ochre over disc with broad white margin, viscid when moist; context not described; margin striate; universal veil as detersile, agglutinated, white patches or other floccose remains unevenly scattered over surface.
from protolog: free, subdistant, white at first soon becoming pale ochre in age, ventricose; lamellulae short, infrequent.
from protolog: 35 - 60 × 3 - 5 mm, white, cylindric, dry; bulb abrupt, ovoid up to 15 mm wide; context firm, white; exannulate; universal veil as fine granules on stipe surface and light yellowish-tinted belts around mid-stipe, as coarse white squamules just above and on basal bulb.
Odor and taste not distinctive.
from protolog: filamentous hyphae 4.2 - 13 μm wide, thin-walled, hyaline to light yellowish in 3% KOH, loosely arranged.
from protolog: [-/-/-] 5.0 - 7.0 × 4.5 - 6.7 μm, (Q = 1.0 - 1.34; Q' = 1.12), hyaline, thin-walled, inamyloid, globose to subglobose to broadly ellipsoid to ellipsoid; apiculus not recorded; contents not recorded; color in deposit not recorded.
from protolog: On sandy soil in coastal sand dunes with Coccoloba uvifera.
from protolog: U.S.A.: PUERTO RICO—Mpio. Río Grande - Piñones Commonwealth For., beach ca. Luiza, 19.xi.1996 E. Horak ZT-6125 (holotype, CFMR; isotype, UPRRP).
The description of the pileus as viscid when moist
suggests that the pileipellis gelatinizes and that,
as a consequence, the species might may not be
assignable to the provisional subsect.
Amanitella. The form of the volval
remains at the stipe base would prohibit placement of
the species in the provisional subsections
Gemmatae, Pantherinae, and
The type of the present taxon should be revised and
described in accord with modern methods.
—R. E. Tulloss
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