Geastrum benitoi

Geastrum benitoi J.C. Zamora in Zamora et al., Persoonia 34: 141. 2015. [pdf]

MycoBank MB810499 

AUTOR: Zamora, J.C.
Clasificación taxonómica

phy Basidiomycota

sbp Agaricomycotina

cls Agaricomycetes

sbc Phallomycetidae

ord Geastrales

fam Geastraceae

gen Geastrum

sp Geastrum benitoi


Unexpanded basidiomata 4–7 mm in diam., subglobose, with a rounded apex or a flat umbo. Exoperidium splitting in (6)7–11(13) more or less equal to unequal rays, (9)10–30(33) mm diam. apparently, (13)15–35(38) mm diam. when forced in horizontal position, arched, often falsely hygrometric. Mycelial layer thin, whitish to pale cream, strongly intermixed with debris from the substrate, more or less strongly adhered to the fibrous layer, but sometimes peeling-off in some parts. Fibrous layer papyraceous to slightly coriaceous when denuded, whitish to pale-cream coloured. Pseudoparenchymatous layer pale cream to greyish cream, not or only superficially cracked, < 0.5 mm thick in dry state, about 1 mm thick when fresh, rather persistent. Endoperidium globose to subglobose, rarely irregular, (4)5–11(13) mm diam., greyish-cream to whitish; endoperidial surface glabrous or almost so, in newly expanded basidiomata covered with the mesoperidium, which is composed by very small, bipyramidal crystals, often in the form of bipyramidal prisms with conspicuous faces, bipyramids also present, gradually dissapearing. Peristome fibrillose, mostly darker than the endoperidial surface, broadly conical to almost flat, 0.5–1.5 mm high, well-delimited. Stalk present but often very short, 0.2–1.0 mm high, whitish. Apophysis absent or badly developed, concolorous with the endoperidium. Columella intruding about 1/3–1/2 into the glebal mass. Mature gleba dark greyish brown.

Basidia narrowly ellipsoid to subcylindric or more or less lageniform, 15–23 × 4.5–6.5 µm, with (3)4–7(8) short sterigmata. Basidiospores mostly globose to subglobose, a few ovoid, (3.5)4.0–5.0(5.5) µm diam., brownish to yellowish brown, with 0.3–0.5(0.6) µm high brown, irregular warts, ornamentation verrucose. Broadest capillitial hyphae 4.5–6.5 µm wide, aseptate, very rarely branched, normally straight, thick-walled (walls 2.0–3.0 µm thick), with narrow lumen, mostly visible; tips acute to rounded; surface covered with debris or not. Endoperidium composed of 2.0–5.0(6.0) µm wide, yellowish to yellowish brown, aseptate, mostly unbranched, slightly sinuous, strongly intertwined, thick-walled hyphae, lumen visible; protruding hyphae absent or very sparse and almost indistinct. Peristomal hyphae 2.5–7.5 µm wide, light brown, aseptate, mostly unbranched, thick-walled (walls 1.0–2.5 µm thick), lumen visible, straight to somewhat sinuous, narrowing at base and apex, tips mostly acute to more or less rounded. Mesoperidium present on the endoperidium and pseudoparenchymatous layer surfaces, consisting of 18–35 diam., bipyramidal crystals of COD, intermixed with some 1.0–3.0 µm wide, hyaline, branched, thin-walled, clamped hyphae. Pseudoparenchymatous layer of thin-walled (walls mostly ≤ 1 µm thick), hyaline to yellowish cells, variable in shape and size, about 12–75 × 10–32 µm. Fibrous layer with 1.5–5 µm wide, hyaline to very pale yellowish, aseptate, straight or slightly sinuous, intertwined, mostly unbranched, comparatively thick-walled (walls 0.5–2.0 µm thick) hyphae, lumen more or less visible. Mycelial layer double-layered; inner layer consisting of 1.5–3 µm wide, strongly glued together, more or less hyaline, branched, thin-walled and clampled hyphae; outer layer with 1–3.5 µm wide, hyaline to somewhat yellowish, aseptate, rarely branched, comparatively more or less thick-walled (walls 0.5–1.5 µm thick) hyphae, lumen hardly visible. Rhizomorphs covered with rose-like aggregates of bipyramidal crystals.


Ecología y distribución

Solamente conocida de suelos arenosos silíceos en la Península Ibérica, que forma parte del bioma de «matorral y bosques mediterráneos» de la ecozona paleártica. ESP: Ba, J, M.


Referencias de la especie en el territorio
  • Calonge, FD, Zamora JC. 2003. Geastrum arenarium encontrado en España y nuevo para Europa. Boletín de la Sociedad Micológica de Madrid 27: 59–61. (subGeastrum arenarium”) [ESP: M] [pdf]
  • Jeppson M. 2013. Jordstjärnor. Mykologiska publikationer 6: 1–228. (subGeastrum arenarium”) [ESP: M]
  • Jeppson M, Nilsson RH, Larsson E. 2013. European earthstars in Geastraceae (Geastrales, Phallomycetidae) – a systematic approach using morphology and molecular sequence data. Systematics and Biodiversity 11(4): 437–465. (subGeastrum arenarium”) [ESP: M] [pdf]
  • Zamora JC, Calonge FD, Martín MP. 2015. Integrative taxonomy reveals an unexpected diversity in Geastrum section Geastrum (Geastrales, Basidiomycota). Persoonia 34: 130–165. (Protologue) [ESP: Ba, J, M] [pdf]


Especímenes en colecciones científicas

* material secuenciado

Espécimen de referencia marcado en negrita

  • Ba: Herb. Zamora 615.
  • J: MA-Fungi 8106.
  • M: MA-Fungi 87324* (holotipo), isotipos en AH 45201 y UPS F-700352;  MA-Fungi 16940; MA-Fungi 68191*; MA-Fungi 53523 (duplo herb. Zamora 13); herb. Zamora 76*; herb. Zamora 124; herb. Zamora 180; herb. Zamora 208; herb. Zamora 209; herb. Zamora 210; herb. Zamora 214; herb. Zamora 317; herb. Zamora 470; herb. Zamora 471; herb. Zamora 498; herb. Zamora 500; herb. Zamora 542; herb. M. Jeppson MJ9531*.


Secuencias en bases de datos públicas y obtenidas de material del territorio


Cuerpos fructíferos. MA-Fungi 87324 (holotipo).

Detalles de los cuerpos fructíferos. Arriba a la derecha: peristoma. Abajo a la derecha: pseudoestípite. MA-Fungi 87324 (holotipo).

Cuerpos fructíferos. Herb. Zamora 542.

Detalles micromorfológicos al microscopio electrónico de barrido. Izquierda: cristales de oxalato cálcico dihidratado sobre el endoperidio. Derecha: basidiospora. MA-Fungi 87324 (holotipo).

Zamora J.C. 2021. Geastrum benitoi J.C. Zamora. Fichas SIM 28 (Actualizada el 19-I-2021). Disponible en: