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

AGROSTIS/POACEAE
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Agrostis hyemalis (Walter) Britton, Sterns, & Poggenb., (of winter), TICKLE GRASS, SPRING BENT
GRASS, WINTER BENT GRASS, FLY-AWAY GRASS. Tufted perennial 15–75(–80) cm tall; leaf blades 0.5–
2(–3) mm wide; panicles narrow at start of flowering, later becoming very open; main panicle
branches in whorls, at least some 5–15 cm or more long, rebranched only toward the tips, the
spikelets clustered near the tips. Open areas, usually sandy soils throughout much of TX; se
Canada and widespread in the e 1/2 of the U.S. Late Apr–early Jun. Rabinowitz and Rapp (1979)
found that while some seeds fall from the inflorescence while it is attached to the plant, the “remaining
seeds are dispersed when the panicle breaks from the parent and rolls in the wind
(long-distance tumble dispersal).” The inflorescences are thus acting as “tumbleweeds.” We are
tentatively following Gould (1975b), Sutherland (1986), Kartesz (1994, 1999), and Harvey (ined.—
Flora of North America treatment) in recognizing the similar A. scabra (ROUGH BENT GRASS) as
a distinct species. However, Jones et al. (1997), Hatch (2002), and Turner et al. (2003) synonymized
A. scabra with A. hyemalis, while Yatskievych (1999) treated it as a variety of A. hyemalis.
Harvey (ined.) noted A. hyemalis differs in “its smaller spikelets and anthers, more conspicuous
culm leaves, and perceptibly more clustered spikelets.” Further study will be needed to determine
the appropriate rank at which to recognize this variation. Harvey (ined.) separateed the
two species as follows:
1. Lemma 0.8–1.2 mm long; anthers 0.2–0.3 mm long _______________________________________ A. hyemalis
1. Lemma 1.4–2 mm long; anthers 0.4–0.7 mm long __________________________________________ A. scabra
Agrostis perennans (Walter) Tuck., (perennial), AUTUMN BENT GRASS, UPLAND BENT GRASS, PEREN-
NIAL BENT GRASS. Clumped perennial 30–80(–100) cm tall; basal leaves usually withering by
flowering; leaf blades (1–)2–6 mm wide; spikelets 1.8–3.2 mm long. Moist sand along wooded
streams, open oak woods; Pineywoods and Post Oak Savannah w to Henderson (BRIT) and Robertson
(Turner et al. 2003) cos. and in Red River drainage to Lamar Co. (BRIT); also n Gulf Prairies
and Marshes; throughout e Canada and the e U.S. w to ND and TX, also CA, OR, and WA.
Aug–Oct, occasionally in spring. [A. perennans var. aestivalis Vasey]
Agrostis scabra Willd., (rough to the touch), ROUGH BENT GRASS, TICKLE GRASS. Clumped perennial
usually 30–90 cm tall, similar to A. hyemalis; leaves mostly basal, these usually persisting;
leaf blades 1–2 mm wide; panicles becoming very open, with main branches rebranched only
toward the tips, the spikelets clustered near the tips; spikelets (at least some) (2–)2.2–3(–3.2+)
mm long, often purplish. Waste areas, roadsides; Bowie, Lavaca (BRIT), Dallas, Hardin, and Harris
(Correll & Johnston 1970) cos.; also Jeff Davis Co. (BRIT) in the Trans-Pecos; native in the w
part of the state, but apparently introduced in East TX; widespread in Canada and the U.S. In
East TX flowering in spring. [A. hyemalis var. scabra (Willd.) H.L. Blomq.] This species has often
been synonymized with A. hyemalis—see discussion under that species. At maturity the inflorescence
tends to break off at its base and can function as a tumbleweed (Yatskievych 1999;
Harvey ined.). According to Harvey (ined.), awned and unawned individuals occur together, the
“difference presumably being caused by a single gene.” Harvey (ined.) also noted that the “species
is variable in size, with the extremes consisting of a widespread, lowland, more weedy form,
capable of producing very large panicles (this form is introduced into the southern United
States) and a dwarf form of poorer soils and mountainous regions.”
Agrostis stolonifera L., (stolon-bearing), CREEPING BENT GRASS, RED-TOP BENT GRASS. Mat-forming
or turf-forming perennial, typically stoloniferous; culms decumbent or spreading at base,
sometimes rooting at nodes, 30–100 cm long; leaf blades (1–)2–6 mm wide; panicles contracted,
densely-flowered (open at anthesis, but becoming contracted after flowering), the main panicle
branches rebranched below the middle; spikelets 1.6–3 mm long. Moist areas, pastures, and disturbed
places, often temporarily flooded areas; Cass Co. (Turner et al. 2003) in the Pineywoods;
known from a few widely scattered counties in TX; nearly throughout the U.S. and Canada.