Mycological System

9
GEASTER

CHAR. Peridium double, both persistent; the exterior is corticate, fissured in a stellate manner, distinct from the interior which is papery and splits at the apex. Capillitium is loose, adnate everywhere to the peridium, with spores interspersed (somewhat pedicelled). They are root-bearing, sessile, but the interior peridium is sometimes pedicelled.

MORPHOSIS. Subterranean threads coalesce into a globose or ovate, closed head (often for a long time, e.g., G. coliformis for four months, per Woodward), most often deeply submerged in the earth, where the exterior peridium encloses the interior as the yolk in an egg; having emerged and matured, it immediately splits into more or less regular and deep segments. This exterior peridium is composed of a double, or even triple, layer; the outermost cortical layer is filamentous (e.g., in species where the mouth is shaped) or rigid and crusty (e.g., in species with a rimose mouth, G. mammosus etc.); upon which is placed a distinct salt layer of different texture, initially softer (even sub-gelatinous) then somewhat waxy, resembling a hymenium on the expanded rays, but varied in various ways; within this, there is sometimes present a membrane surrounding the interior peridium, e.g., in G. coliformis and mammosus (per Woodward), duplicated, or at least rudiments in G. umbilicatus and a reticulum in G. hygrometricus. Since it happens that many species can be observed from the first principles, I hope they study their morphogenesis diligently! — The rays and very many differences depend on the nature of the interior layer. Sometimes it splits, whence the exterior peridium is duplicated (G. fornicatus); sometimes it is thick, softer, and contracts upon drying (rimose-incised, e.g., G. hygrometricus), whence the rays are bent inwards!; often it is quite thin and remains contiguous (the rays are then expanded) or separates, with reflexed rays. The singular hygrometric power of the rays, which varies in various species, lies in this nature. The morphogenesis of the interior peridium seems to agree in the genus with the rest of the Lycoperdei, especially Bovista and Tulostoma, but it is more varied; indeed, Micheli also describes and depicts it as initially cellular within like Scleroderma