Texas Fluffgrass

Species of the New World genus Tridens are similar to many other grass species developing panicle-type inflorescences. However, certain features -- often hard to see without magnification and knowledge of basic grass-flower anatomy -- help identify Tridens species:

Spikelets are not compressed laterally, or sideways, but rather are plump to rounded in cross-section; they accommodate 3 or more florets. The lemma's 3 prominent veins are hairy, at least below, while the glumes are hairless. Neither glumes nor lemmas bear needlelike awns at their tips. These features help distinguish Tridens texanus from other Tridens species:

The panicle-type inflorescence is open and diffuse, not spike-like. Of the lemma's 3 nerves, the ones on the sides vanish at the margin instead of continuing strongly to the edges. The spikelets are relatively large, up to 10 mm long.

In the USA, Tridens texanus occurs in the south-central states of New Mexico and Texas. In Mexico, Tridens texanus occurs in the northern states of Chihuahua, Coahuila, Nuevo León, San Luis Potosí and Tamaulipas.

The genus name Tridens is New Latin meaning "3-toothed," referring to the lemmas of florets of the type specimen upon which the genus was described in 1817 where, at least to the authors, the lemma's three veins appeared to gather at a notched or 2-toothed tip. The name is constructed from the Latin and Greek tri-, meaning "having 3 elements or parts." and the Latin -dēns, meaning "tooth or toothlike part. The species name texanus refers to the US state of Texas, collections from which were examined when, in 1883, Sereno Watson described the taxon which would become Tridens texanus.