Unlike other Agaricus species, A. deserticola does not develop true gills, but rather a convoluted and networked system of spore-producing tissue called a gleba.

When the partial veil breaks or pulls away from the stem or the cap splits radially, the blackish-brown gleba is exposed, which allows the spores to be dispersed.

In 2010, its specific epithet was changed to deserticola after it was discovered that the name Agaricus texensis was illegitimate, having been previously published for a different species.

The species was first described scientifically as Secotium texense by Miles Joseph Berkeley and Moses Ashley Curtis in 1873, based on specimens sent to them from western Texas.

[5] In a 1943 publication, Sanford Zeller compared a number of similar secotioid genera: Galeropsis, Gyrophragmium and Montagnea.

The generic name was to honor William Henry Long, an American mycologist noted for his work in describing Gasteromycetes.

[9] The species was known by this name for about 60 years, until a 2004 phylogenetic study revealed the taxon's close evolutionary relationship with Agaricus,[10][11] a possibility insinuated by Curtis Gates Lloyd a century before.

When the species was known as a Gyrophragmium, Fischer thought it to be close to Montagnites, a genus he considered a member of the family Agaricaceae.

"[12] Elizabeth Eaton Morse believed that Gyrophragmium and the secotioid genus Endoptychum formed a transition between the Gasteromycetes and the Hymenomycetes (the gilled fungi).

[10][11] These adaptations include: a cap that does not expand (thus conserving moisture); dark-colored gills that do not forcibly eject spores (a mechanism known to depend on turgor pressure achievable only in sufficiently hydrated environments); and a partial veil that remains on the fruit body long after it has matured.

[20] This form of growth is called secotioid development, and is typical of other desert-dwelling fungi like Battarrea phalloides, Podaxis pistillaris, and Montagnea arenaria.

Molecular analysis based on the sequences of the partial large subunit of ribosomal DNA and of the internal transcribed spacers shows that A. deserticola is closely related to but distinct from A. aridicola.

[26] Numerous white rhizoids are present at the base of the stem; these root-like outgrowths of fungal mycelium help the mushroom attach to its substrate.

Unlike other Agaricus species, the spores of A. deserticola are not shot off, but are instead dispersed when they sift out of the dried, mature fruit bodies after the peridium breaks open.

In this test, aniline plus nitric acid are applied to the surface of the fruit body, and if positive, a red or orange color forms.

Podaxis pistillaris has a cylindrical to oval white to brownish cap with a paper-thin wall atop a slender stem.

[20][28] However, one popular field guide to North American mushrooms suggests they are edible when they are young, and have a pleasant odor and mild taste.

Fruit bodies start as enlarged tips on the rhizomorphs, and manifest as numerous small, almost-spherical protuberances just beneath the surface of the soil.

At about the time the peridium reaches 1 cm (0.4 in) or slightly more in diameter, the columella exerts an upward tension on the tissue of the partial veil, and it begins to pull away from the stem.

[28] The range of the fungus is restricted to southwestern and western North America, where it fruits throughout the year, typically during or following cold, wet weather.

[2] The mushroom used to be common in the San Francisco Bay area before land development reduced its preferred habitats.