Amanita xylinivolva is a locally common species with a range extending at least from Andean Colombia to the "mountain islands" that are isolated in high altitude desert of the southwestern Arizona, U.S.A.
Its 15 - 70 mm wide cap is pale yellow and becomes paler (except sometimes for the central part) with aging. The volva is either absent from the cap or distributed on the cap as cottony white patches that sometimes become sordid with age.
The gills are free to narrowly adnate, subdistant to crowded, whitish to cream to pale buff in mass, and sordid white (sometimes with yellow tint) in side view. The short gills are truncate to subtruncate to attenuate.
The stem is 45 - 135 × 4 - 13 mm, quickly loses its fragile skirt-like annulus, and usually has a cottony white, submembranous limb of volva on the top of a rather prominent bulb (10 - 25 × 15 - 30 mm).
double click in markup mode to edit.
The spores measure (6.2-) 8.0 - 10.2 (-12.2) × (5.2-) 7.2 - 9.5 (-10.8) µm and are globose to subglobose to broadly ellipsoid (infrequently ellipsoid and inamyloid. Clamps have not been found on bases of basidia.
Between the above cited extremes of its geographic range, this species has also been collected in Costa Rica and central Mexico. The species is associated primarily with oak (Quercus) and pine (Pinus).—R. E. Tulloss
Tulloss, Ovrebo & Halling. 1992. Mem. New York Bot. Gard. 66: 4, figs. 1-3, 29.
"Cottony Volva Amanita"
=[?]Amanita gemmata sensu Guzmán & Varela. 1978. Caldasia 12: 328.
=Amanita gemmata sensu States. 1990. Mushr. Truff. Southw.: 56 & 57 (upper pl.).
non Amanita gemmata (Fr.) Bertillon in DeChambre
=Amanita gemmata f. gracilis sensu Santiago et al. 1984. Bol. Soc. Mex. Micol. 19: 97.
non Amanita gemmata f. gracilis E. J. Gilbert in Konrad & Maubl. 1925. Icones Selectae Fungorum 1: tab. 6.
The editors of this site owe a great debt to Dr. Cornelis Bas
whose famous cigar box files of Amanita nomenclatural information
gathered over three or more decades were made available to RET for computerization
and make up the lion's share of the nomenclatural information presented on this site.
Due to delays in data processing at GenBank, some accession numbers may lead to dead pages.
These pages will eventually be made live, so try again later.
HUA; isotypes, CSU & NY
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 not directly from the protolog of the present taxon and not cited as the work of other authors is based on original research of R. E. Tulloss.
15 - 66 mm wide, when young pale yellow (creamier than 3A3 to faintly browner than 3A4, near 2.5Y 8/6) or dull yellow (duller than 4A4-5), lightening when older to dull creamy yellowish buff (including 3A2-3), sometimes darker in disk (e.g., 3-4A3 to 5C5 over disc and cream over margin or 5B6 over disc with remainder approximately 4A4), sordid yellowish tan with age and in situ drying, not otherwise discoloring, hemispheric to broadly conic with faint or distinct umbo at first, expanding to broadly convex to planar, sometimes becoming depressed to concave, slightly tacky, dull; context white to buff to pale cream but yellow (e.g., 4A3) or yellowish beneath pileipellis, unchanging when cut or bruised, 2 - 6.5 mm thick, thinning evenly to margin; margin sulcate to tuberculate-sulcate (0.25R - 0.5R) in less robust specimens, but barely striate or becoming striate with age in larger ones, occasionally appendiculate with membranous bits of partial veil; universal veil absent or as patches, white to off-white, sometimes becoming sordid, thin, smooth, detersile, scattered or concentrated over disk.
free to narrowly adnate with decurrent line on stipe apex (lens), subdistant to crowded, whitish to cream to pale buff in mass, watery or sordid white (sometimes with yellowish tint) in side view, not discoloring when cut or bruised although somewhat dingy at pileus margin, drying to 5A-B4 to slightly grayer than 5B4, 2 - 8 mm broad, rounded at pileus margin, edges white and finely fimbriate (with 10× lens); lamellulae truncate (shortest) to subtruncate to attenuate, of diverse lengths, unevenly distributed.
45 - 131 × 4 - 13 mm, white to creamy to whitish buff, becoming dingy pale yellow (e.g., 5B2) or faintly brown or not changing from handling, narrowing upward, flaring at least slightly at apex, longitudinally striatulate, finely fibrillose and shiny above, lower portion finely shaggy flocculent; bulb 10 - 24 × 15 - 30 mm, subglobose, sometimes veritcally compressed, sometimes marked to abrupt, at times subradicating, sometimes splitting longitudinally; context white to whitish buff, sometimes with watery tan streaks, rarely with orange-brown (7D6) stain in bulb, unchanging when cut or bruised or faintly tan where bruised, solid when young, slightly hollowed at maturity; partial veil superior to submedian, short, tearing, evanescent, white above, approximately concolorous with yellow of pileus below, sometimes shredding and hanging from pileus margin or deposited in shreds on stipe below original position; universal veil as loose limb or limbs leaning on lower stipe above bulb, white, sometimes becoming sordid, thin, submembranous, circumcissile, sometimes becoming areolate or breaking into warts, topmost point of limb 16 - 46 mm from base of bulb, more flimsy and more easily lost than limb in taxa of Amanita section Phalloideae such as A. bisporigera Atk.
Odor musty or earthy (holotype) or of lacquer to faintly raphanoid (Montoya Esquivel 1335; Tulloss 8-18-91-D) or "parecido a las jicamas" (Montoya Esquivel 1261). Taste nondescript.
3% KOH - faint orange on pileus (4A6 in Montoya Esquivel 1335). 10% FeSO3 - negative. Phenol - drop on pileus 8F8; drop on lamellae 10F5. Spot test for laccase (syringaldazine) - negative throughout basidiome. Spot test for tyrosinase (paracresol) - positive throughout basidiome. Test voucher specimens: holotype; Franco-M. 421, 446, 896; Montoya Esquivel 1335.
filamentous, undifferentiated hyphae 2.0 - 7.0 µm wide, interwoven, branching; acrophysalides thin-walled, ovoid to clavate, up to 66 × 40 µm; vascular hyphae 1.0 - 2.5 µm wide, uncommon.
bilateral; wcs = 40 - 60 µm with moderate to very good rehydration; subhymenial base ?, with angle of divergence usually shallow (up to 45°); filamentous, undifferentiated hyphae 1.8 - 15.0 µm wide, branching; inflated cells single or in short chains, up to 99 × 35 µm, mostly 20 - 30 µm wide, dominating central stratum and shallow subhymenial base [more data needed], occasionally terminal, apparently with only terminal cells of this type diverging and then usually at angle under 45°; vascular hyphae not observed.
wst-near = 15 - 30 µm with moderate to very good rehydration; wst-far = 25 - 45 µm with moderate to very good rehydration; cellular (pseudoparenchymatous) to subcellular, in layer three to four cells thick below bases of longest basidia/-oles, with cells sometimes clearly in branching chains, subglobose to ellipsoid, usually 22 × 13 µm or smaller (rarely to 40 × 20 µm), often with major axis roughly parallel to hymenial surface, with larger cells farther from bases of basidia, with uninflated to partially inflated short hyphal segments present, but scarce in some regions, with basidia arising singly or in pairs from cells of all types.
36 - 62 × (9.0-) 10.0 - 15.0 µm, 4-, 2-, and 1-spored, with 4-spored usually dominating, but sometimes comprising only about 50% of basidia examined, thin-walled, with sterigmata up to 7.5 × 2.0 µm; clamps not observed.
On pileus: branching filamentous, undifferentiated hyphae 1.5 - 12.5 µm wide, dominant in some regions, loosely interwoven near outer surface becoming more densely packed near gelatinizing zone above pileipellis, with terminal segments inflated up to 18.0 µm wide; inflated cells terminal or paired in chain, with walls thin or up to 0.8 µm thick, plentiful, locally dominant, ovoid to elongate to narrowly clavate, up to 71 × 46 µm; vascular hyphae 1.2 - 6.5 µm wide, uncommon to locally common or in tangles. From limb on top of bulb: having similar structure, but with larger proportion of filamentous, undifferentiated hyphae more tightly interwoven, gelatinizing.
filamentous, undifferentiated hyphae 2 - 8.5 µm wide, in loose tangle, rather frequently branching, lacking any dominant orientation, dominant throughout much of tissue, mostly of narrower diameters; inflated cells small, scattered, with larger ones in clusters, terminal, subglobose to ellipsoid to ovoid (up to 58 × 45 µm) or occasionally narrowly clavate (up to 120 × 35 µm), with subterminal segments slightly inflated rather short and having constrictions at septa; vascular hyphae scarce or absent.
from protolog: [328/16/6] (6.2-) 8.0 - 10.2 (-12.0) × (5.2-) 7.2 - 9.5 (-10.8) μm, (L = (8.5-) 8.7 - 9.5 (-9.8) μm; L' = 9.0 μm; W = 7.9 - 8.8 (-9.3) μm; W' = 8.3 μm;
Q = (1.0-) 1.02 - 1.19 (-1.39); Q = 1.05 - 1.12 (-1.15); Q' = 1.08),
hyaline, colorless, smooth, thin-walled, inamyloid, globose to subglobose to broadly ellipsoid, infrequently ellipsoid, often adaxially flattened; apiculus sublateral to subapical, cyindric, often rather prominent; contents guttulate; color in deposit not recorded.
composite of all material revised by Tulloss: [548/27/15] (6.2-) 8.0 - 10.2 (-12.2) × (5.2-) 7.2 - 9.5 (-10.8) µm, (L = (8.5-) 8.6 - 9.5 (-9.8) µm; L’ = 9.1 µm; W = 7.9 - 8.8 (-9.3) µm; W’ = 8.4 µm; Q = (1.0-) 1.02 - 1.18 (-1.39); Q = 1.05 - 1.11 (-1.15); Q’ = 1.09), hyaline, colorless, thin-walled, smooth, inamyloid, globose to subglobose to broadly ellipsoid, infrequently ellipsoid, usually at least slightly adaxially flattened; apiculus sublateral to (rarely) subapical, cylindric, often rather prominent; contents monoguttulate with or without additional small granules, infrequently multiguttulate; ? in deposit.
Solitary to subgregarious to gregarious. Colombia: At 1800 to 2350 m elev. Under Cupressus lusitanica or in Quercus humboldtii forest. Costa Rica: At 2500 m elev. With Q. seemannii (Franco-M. 1099). Edo. México: At 2850 m elev. In Pinus-Abies forest. Tlaxcala edo., México: Solitary to subgregarious. In Quercus-Pinus forest or in Abies-Alnus-Pinus forest or in Pseudotsuga-Abies-Quercus-Pinus-Arbutus forest or in Pinus-Quercus-Abies forest or in Abies-Pinus forest or in forest of P. leiophylla and Arbutus. Arizona, U.S.A.: At 1900 to 2600 m elev. Under Pinus arizonica originating deep in litter with Pseudotsuga menziesii nearby or in grassy open area with scattered P. arizonica or with Ps. menziesii, P. engelmannii, P. arizonica, Juglans major, Quercus arizonica, and Q. hypoleucoides or with Abies concolor, Ps. menziesii, P. arizonica, Juniperus deppeana, and P. chihuahuana or with Quercus and Pinus.
COLOMBIA: ANTIOQUIA—Mpio. Guarne - ca. Ctr. Exp. Piedras Blancas, 14± km E of Medellín, 11.xi.1986 C. L. Ovrebo 2487 (holotype, HUA; isotype, CSU; isotype, NY). Mpio. Santa Rosa de Osos - Estación La Oculta, along rd. from San José de la Montaña to Aragon, 26.xi.1986 C. L. Ovrebo 2561 (paratype, HUA).
CAUCA—Los Araoz, 12.iv.1968 R. Singer B6045 (paratype, F 1013493, as "A. frostiana"). Mpio. Popayán - vereda "Rio Blanco," Hacienda Cantaclaro, prop. Mauricio Pinzón, 7.v.1990 A. E. Franco-M. 421 (paratype, CUVC; paratype, NY).
CUNDINAMARCA—Mpio. Pacho - btwn. Pacho and Páramo Guerrero, near Pacho rd., 9.iv.1968 R. Singer B6031 (paratype, F 1014392, as "A. gemmata"). Cerra de Las Mercedes, road between Bogotá and La Mesa, s.d. Guzmán 4627 (paratype, COL; paratype, ENCB, n.v.).
NARIÑO—Mpio. La Florida - 27± km from Pasto, Hacienda "El Barranco," prop. Francisco Villareal, 11.v.1990 A. E. Franco-M. 446 (paratype, NY; paratype, PSO).
SAN JOSÉ—Ctn. Dota - San Gerardo de Dota #1, 5± km SW of Cerro de la Muerte, Albergue de Montaña Savegre (Cabinas Chacón) [9°33’2” N/ 83°48’27” W, 2200-2350 m], 7.xi.1993 R. E. Halling, G. M. Mueller, B. A. Strack, M. Mata, Loengrin Umaña & A. E. Franco-M. [Franco-M. 1099] (NY).
HIDALGO—Mpio. Molango - Laguna Atezca [19°20’41” N/ 98°16’31” W, 2640 m], 18.vii.1996 A. Estrada Torres & L. Varela Fregoso s.n. [Tulloss 7-18-96-G] (RET 253-1; TLXM).
TLAXCALA—Mpio. Huamantla - Parq. Nac. La Malinche, La Cañada Grande, E slope of Volcán La Malintzi [19°14’45” N/ 97°54’56” W, 3110 m], 28.iv.1988 A. Kong Luz 963 (RET 144-2; TLXM n.v.). Mpio. Panotla - 1 km N of San Francisco Temezontla [19°20’41” N/ 98°16’31” W, 2640 m], 12.vii.1992 A. Montoya Esquivel 1005 (RET 144-8; TLXM, n.v.), 17.x.1992 A. Montoya Esquivel 1261 (RET 144-1: TLXM, n.v.). Mpio. Sierra de Terrenate - N of Villarreal, Barranca El Conejo, 6.vii.1990 G. Santiago Martínez 132 (RET 144-5; TLXM n.v.). Mpio. Tlaxco - Cerro El Peñón [19°41'19" N/ 98°14'02"W, 2775 m], 9.viii.1991 A. Montoya Esquivel 1054 (RET 144-9; TLXM); Cerro El Peñon, Ejido Mariano Matamoros, 11.viii.1993 A. Montoya Esquivel 1335 (RET 144-4; TLXM n.v.); Parada El Conejo, km 31 carretera Apizaco-Poza-Rica, Sierra de Tlaxco, 10.viii.1989 A. Montoya Esquivel 432 (RET 144-7; TLXM n.v.). Mpio. Trinidad - Parq. Nac. La Malinche, SE slope of Volcán La Malintzi, 4-7 km W of Francisco Javier Mina, 7.ix.1994 A. Montoya Esquivel 1485 (RET 144-6; TLXM n.v.).
VERACRUZ—Mpio. Xico - Atopa, 1.9 km W of Tembladeras, Ejido Ingenio El Rosario, zona E of Cofre de Perote, 19.viii.1985 L. Montoya Bello 255 (NY).
ARIZONA—Cochise Co. - CMP site #4, Pine Cyn. Methodist Church Camp [UTM 588 340], 23.viii.1989 R. M. Chapman s.n. [CMP0247] (LAM, as "A. calyptrata"; RET), 26.viii.1991 Godwin Mchau s.n. [CMP1406] (LAM, as "A. crenulata"); CMP site #5, Rustler Pk., ca. For. Service Stn. to .8 km S [UTM 630 308], 28.viii.1991 R. M. Chapman s.n. [CMP1668] (LAM, as "A. gemmata"), 14.viii.1990 R. M. Chapman s.n. [CMP0426] (LAM, as "A. gemmata"); Site #31, Turkey Pk. [UTM 643 330], 14.viii.1990 J. S. States s.n. [CMP0398] (LAM, as "A. gemmata"); CMP site #46, Barfoot Pk. [UTM 625 322], 18.viii.1991 R. E. Tulloss 8-18-91-D [CMP0645] (LAM; RET).
Add ? ? L. Ortiz s.n. [CMP1487]?.
Tulloss et al. (1992) compared this species to a number of other similar, but distinct taxa of section Amanita.
From the habit of some specimens from the Chiricahuas (especially the large bulb and sometimes limbate volva), the nonstriate pileus margin in young specimens, and the presence of some attenuate lamellae, at first, I expected those specimens to belong to a taxon of section Phalloideae when I first encountered them in the field; however, this can be easily disproven because the spores of the present taxon are not amyloid.
—R. E. Tulloss
Information to support the viewer in reading the content of "technical" tabs
can be found here.
Tulloss, Ovrebo & Halling
"Cottony Volva Amanita"
RET - (1) Chiricahua Mountains, Cochise County, Arizona, U.S.A.
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.