keys to the vascular plants of east texas - Botanical Research ...

1084 POACEAE/TRIDENS
Tridens buckleyanus (L.H. Dewey) Nash, (for Samuel Botsford Buckley, 1809–1884, state geologist
of TX and plant collector), BUCKLEY’S TRIDENS, BUCKLEY’S FLUFF GRASS. Plant 40–80 cm tall,
nearly glabrous; leaf blades 1–4 mm wide; panicle 10–28 cm long; spikelets 7–10 mm long.
Shaded banks, forest margins, juniper-oak woodlands, rocky limestone soils; Bexar, Comal,
Hays, and Travis (BRIT) cos. on sw edge of East TX; also s and e Edwards Plateau and s
Lampasas Cut Plain (Mills Co.—Turner et al. 2003); endemic to TX (Kartesz 1999; Carr 2002b,
2002c). Late summer–fall. [Sieglingia buckleyana L.H. Dewey, Triodia buckleyana (L.H. Dewey)
Vasey ex Hitchc.] (RARE 2001, 2002b: G3G4S3S4) � E
Tridens congestus (L.H. Dewey) Nash, (congested, crowded together), PINK TRIDENS, PINK FLUFF
GRASS. Plant 30–75 cm tall, glabrous; leaf blades 1–5 mm wide; panicle 5–8(–10) cm long; spikelets
usually 5–10 mm long; glumes and lemmas thin, papery, usually pink-tinged; lemma apex
deeply cleft. Clay, disturbed sites, low moist areas; scattered in e 1/2 of TX; endemic to TX
(Kartesz 1999; Carr 2002b, 2002c). Apr–Nov. [Sieglingia congesta L.H. Dewey, Triodia congesta
(L.H. Dewey) Bush] This species resembles T. albescens but “usually has shorter panicles, spikelets
that are more or less evenly pink rather than purple-tipped, and more deeply cleft lemma
apices” (Valdés-Reyna 2003a). E
Tridens eragrostoides (Vasey & Scribn.) Nash, (resembling Eragrostis, love grass), LOVE GRASS
TRIDENS, LOVE FLUFF GRASS. Plant (10–)50–100 cm tall, glabrous or pilose; leaf blades 1–5 mm
wide; panicle 8–25(–30) cm long; spikelets 3–7 mm long. Brushy grasslands, typically in partial
shade; Bexar and Hays (Turner et al. 2003) cos. near extreme sw margin of East TX; widespread
in s 1/2 of TX; AL, AZ, FL, NM, and TX. (May–Jun)Sep–Nov. [Triodia eragrostoides Vasey &
Scribn.]
Tridens flavus (L.) Hitchc., (pale yellow), TALL REDTOP. Plant 60–180 cm tall, glabrous; lower leaf
sheaths laterally compressed and keeled, often giving base of plant a flattish aspect; leaf blades
(3–)5–10(–13) mm wide; panicle 15–35(–40) cm long; spikelets 5–9(–10) mm long, green or usually
purplish. Widespread in e 1/2 of TX, scattered further w; the county distribution map does
not distinguish the 2 varieties. Aug–Nov.
1. Inflorescence erect, not drooping, the branches stiffly spreading, with basal swollen area (= pul–
vinus) extending completely around branch, conspicuously pubescent, not greasy _________ var. chapmanii
1. Inflorescence drooping, the main axis and branches bending or curving, the branches with basal
swollen area on upper side of branch only, glabrous or with inconspicuous pubescence, greasy
________________________________________________________________________________ var. flavus
var. chapmanii (Small) Shinners, (for A.W. Chapman, 1809–1899, American botanist and author
of Flora of the Southern United States), CHAPMAN’S TRIDENS. Spikelets on pedicels 3–20 mm
long. Pinelands, forest openings; mainly Pineywoods, also Brazos and Van Zandt (BRIT) cos. in
Post Oak Savannah; se U.S. from VA s to FL w to MO, OK, and TX. [Sieglingia chapmanii Small,
Tridens chapmanii (Small) Chase, Triodia chapmanii (Small) Bush]
var. flavus, PURPLETOP, REDTOP, GREASE GRASS. Spikelets with pedicels 1–5 mm long; inflorescence
branches greasy. Prairies, old fields, open woods, roadsides, disturbed areas; Pineywoods and
Gulf Prairies and Marshes w to e Edwards Plateau and plains country; se Canada (Ont.) and
widespread in e U.S. w to MN and NM. [Poa flava L., Triodia flava (L.) Smyth] The common
name GREASE GRASS is the result of the greasy feel on the fingers after running them over the
inflorescence. Small globules of a greasy substance are secreted where the inflorescence
branches arise and at the nodes of the upper stem (Yatskievych 1999).
Tridens muticus (Torr.) Nash, (blunt, pointless), AWNLESS FLUFF GRASS. Plant 20–80 cm tall; culm
nodes often bearded; panicle narrow, elongate, 6–20(–25) cm long; spikelets 7–13 mm long,
short-pedicelled, appearing sessile, not densely crowded, purplish. Dry disturbed sites; widespread
in TX; the county distribution map does not distinguish the 2 varieties. Apr–Nov.