When grown in humid conditions, such as might typically be found in a temperate deciduous forest, " Calostoma " species develop a thicker, more gelatinous exoperidium ( the outermost peridial layer ).
12.
The exoperidium of " Ollum " species, in comparison, has a thin tomentum of fine hairs; fruit bodies are funnel-shaped and have either a constricted base or a distinct stipe.
13.
Unlike some other puffball species, the peridium does not differentiate into a distinct exoperidium and endoperidium; rather, the outer layer develops the features of a pseudoparenchyma ( a tightly organised tissue where the tightly packed cells resemble plant parenchyma ) as the radial and tangential hyphae become interweaved.
14.
The closely related species " Battarrea diguettii " is known in the United States from the Mojave desert, and differs from " B . phalloides " in that the spore sac emerges by ripping through the top of the exoperidium, rather than by circumscissile rupture.
15.
Curtis Gates Lloyd described " Bovistoides simplex " from a South African specimen in 1919, but in 1942, William Henry Long examined that specimen and concluded that it was a weathered spore sac of " M . coliforme " that had become detached from the outer star-shaped exoperidium.
