About Tridens texanus (S.Watson) Nash
Tridens texanus is a species in the New World grass genus Tridens. Like many other grass species, species of Tridens produce panicle-type inflorescences, but specific identifying features set the genus apart from other grasses. These features are often difficult to see without magnification and prior knowledge of basic grass flower anatomy. For Tridens species, including Tridens texanus, spikelets are not laterally (sideways) compressed, but instead are plump to rounded in cross-section, and each holds 3 or more florets. The three prominent veins on the lemma are hairy, at least on their lower portion, while the glumes are hairless. Neither glumes nor lemmas have needle-like awns at their tips. There are additional features that distinguish Tridens texanus from other species within the genus Tridens. Its panicle-type inflorescence is open and diffuse, rather than spike-like. Of the three nerves on the lemma, the lateral nerves end at the margin instead of extending strongly all the way to the edge. Its spikelets are relatively large, growing up to 10 mm long. In the United States, Tridens texanus is found in the south-central states of New Mexico and Texas. In Mexico, it occurs in the northern states of Chihuahua, Coahuila, Nuevo León, San Luis Potosí and Tamaulipas. In Texas, Tridens texanus lives in brushlands. On the Southwestern Plains, it is reported to occur infrequently on rocky limestone soils. A documented individual seen in photos on this page was found on a limestone hill slope in a clearing within an Ashe Juniper forest. In a study of grasses in a mesquite woodland in north-central Nuevo León, Mexico, Tridens texanus was the fourth most frequently recorded grass species, found in approximately 13% of sampled sites. The more frequent companion species recorded in this study, in descending order of occurrence, were Cenchrus ciliaris (listed as Pennisetum cilare), Setaria texana, and Bouteloua trifida. Tridens texanus has also been collected at the edge of a field in Mexico.
