Spiny Puffball

Appearance

The fruit bodies of ''L. echinatum'' are 2–4 cm wide by 2–3.5 cm tall, and are roughly spherical, or pear-shaped. The exterior surface is crowded with spines that may be up to 0.6 cm long. According to Curtis Gates Lloyd, American specimens have more slender spines than European ones.

Initially white and becoming dark brown in maturity, the spines are often joined at the tips in groups of three or four. In this form the puffballs resemble acorn caps of burr oak, with which they may readily be confused. The spines slough off in age, revealing a somewhat net-like or reticulated surface.

The fruit body has a small base that is an off-white or purple-gray color, and it may be attached to the growing surface by thin white cords . The internal contents of the puffball contain the gleba, a mass of spores and associated spore-producing cells. In young specimens the gleba is white and firm, but as the puffball ages, it turns yellowish and then brown to purple-brown and powdery. Mature specimens develop a pore at the top of the fruit body through which spores are released when hit by falling raindrops.

The spores of ''L. echinatum'', roughly spherical with warts on the surface, have diameters between 4 and 6 µm. The capillitia are elastic, brown in color, contain small pores, and are 5–8 µm thick. The basidia may be attached to two to four spores, and the sterigmata are up to 5 µm long.

Like most other puffball species, ''L. echinatum'' is edible when still young and while the gleba is still white and firm. Consumption of older specimens with a non-white gleba, or where the gleba has turned into a powdery spore mass, may cause stomach upsets. This species has a mild taste, and no distinguishable odor, although one source describes the smell of dried fruit bodies as similar to "old ham". One source notes that it is "well flavoured and tender when cooked", while another describes the texture as "somewhat like French toast". Antonio Carluccio recommends sautéeing puffballs with other mushrooms. To avoid possible confusion with potentially deadly ''Amanita'' species, it is recommended to slice young puffballs with a longitudinal cut to ensure that the flesh is devoid of any internal structures.

Distribution

''Lycoperdon echinatum'' can be found either solitary or in small groups. It typically grows on the ground in deciduous forests and grassy areas, glades and pastures, on moss, humus, or woody debris. The fungus has been noted to have a preference for beech woods. Fruit bodies may make their appearance anytime from the late spring to autumn. Older specimens are more likely to be overlooked, as their brown color blends into the surrounding environment of dead leaves and dead wood. The puffball is used by various species of scuttle flies as larval food.

This species has been collected from eastern central Africa, China, Costa Rica, Iran, Japan, and Europe . In North America, it is "locally frequent" east of the Rocky Mountains.

It is considered a threatened species in the Åland Islands of Finland. A study of the species' distribution in Sweden reported that in the 1940s and 50s, it grew in beech woods with broad-leaved grasses and herbs in topsoils with soil pH levels between 5.0 and 6.6, but the populations have since decreased owing to soil acidification during the last several decades. Fruit bodies collected near arsenic-contaminated sites have been shown to bioaccumulate arsenic, largely in the form of arsenobetaine.