Geastrum federeri A. Paz & C. Lavo

Diagnosis fuente 
Basidiomata hypogeous, indehiscent, 0.8–2.6 × 0.6–2.3 cm diam, subglobose, slightly depressed at the top, with mycelial base, and without pedicel, apophysis and peristome. Peridium thick, 2.5–3.2 mm, non-hygrometric, 3-layered, with exoperidium, mesoperidium and endoperidium. Exoperidium not fissuring at maturity into a characteristic star-like structure, fibrous, leathery, often detached from mesoperidium, yellowish to light brown in cross section, turning red in Lugol’s solution, 95–122 brown in cross section, turning red in Lugol’s solution, 95–122 μm thick, two-layered, the outer stratum with incrustations, detaching in patches, composed of 3.1–7.4 μm wide skeletal hyphae and rhizomorphs with bipyramidal crystals inside, stratum formed by thick-walled 0.4–0.9 μm wide. Mesoperidium thick, 275–305 μm, pale yellowish cream in colour, with purplishpurple reflections, compact, persistent, not reacting with Lugol’s solution, with plectenchymatous structure, intricate, formed by elongated hyphae with very sinuous septa, measuring ?n average of 4.2 × 9.5 μm¸ with thin walls, which widen slightly towards the gleba. Endoperidium very thin (maximum two rows towards the gleba. Endoperidium very thin (maximum two rows of cells), absent in some areas, formed by subglobose cells, interspersed with other more elongated elements. Gleba initially white, compact, changing to dark brown, powdery mass, with a robust, club-shaped columella, with a rounded apex, which penetrates a third of the height of the gleba.
Capillitium formed by abundant straight hyphae with 0.65 μm thick walls, without crystals. Basidia narrowly ellipsoid to subcylindrical or more or less lageniform, 19–26 × 4.5–7.1 μm, with 5–8 short sterigmata. Basidiospores globose, 4.1–4.8 μm diam, greenish yellow when young, brownish at maturity, with reticulate ornamentation, formed by intense greenish yellowish ridges, reaching a height up to 5 μm, joining at the bases to form a network with alveoli very irregular in shape and size.