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

MUHLENBERGIA/POACEAE
983
10. Lemma with a tuft of hairs at base; culms glabrous and shining between the nodes
and at the nodes OR puberulent and dull just below the nodes.
11. Lemma with a conspicuous awn (3–)5–10(–18) mm long; culms puberulent and
dull just below the nodes (use hand lens or dissecting scope); species rare, if
present, in East TX __________________________________________________ M. sylvatica
11. Lemma awnless or with an awn to 3 mm long (rarely to 8 mm in M. bushii);
culms puberulent and dull just below the nodes OR nodes and internodes glabrous
and shiny; including species widely scattered in East TX.
12. Glumes overlapping nearly to middle, ovate, abruptly tapering to an awn
tip; plants with few axillary panicles, but those present usually long-exserted,
the peduncles to 11 cm long _____________________________________ M. sobolifera
12. Glumes not overlapping or overlapping only at base, lanceolate, gradually
tapering to an awn tip; plants with numerous axillary panicles, these not
long-exserted (often partially enclosed in leaf sheath), the peduncles usually
only 1–2 cm long.
13. Glumes 1/2–2/3 as long as lemma, 1.2–2(–2.5) mm long; ligule 0.7 mm
or less long; terminal panicle often well-exserted; leaves of the lateral
branches often shorter and narrower than those of the main culms _______ M. bushii
13. Glumes 3/4 as long to slightly longer than lemma, usually ca. 2–4.1 mm
long; ligule 0.7–1.4(–1.7) mm long; terminal panicle usually not wellexserted
(at least base enclosed in subtending leaf sheath); leaves of
the lateral branches about same length and width as those of the main
culms _____________________________________________________ M. frondosa
Muhlenbergia bushii R.W. Pohl, (for Benjamin Franklin Bush, 1858–1937, amateur botanist of
Missouri, and discoverer of this species), NODDING MUHLY. Rhizomatous perennial; culms 30–
100 cm tall, erect, becoming much-branched above, nodes and internodes glabrous and shiny;
leaf sheaths rounded or slightly angled; ligule 0.7 mm or less long; panicles numerous, slender;
spikelets 2.5–3.6 mm long; lemma pilose basally, awnless or with awn rarely to 8 mm long. Rich
or low woods, along streams, often calcareous conditions; Grayson, Hunt, McLennan, Van Zandt
(BRIT), Dallas, Navarro (TAES), and Travis (Turner et al. 2003) cos.; also Cross Timbers and Prairies;
much of the c U.S. from IN s to LA w to NE and TX, also GA and WV. Jul–Oct. [M.
brachyphylla Bush]
Muhlenbergia capillaris (Lam.) Trin., (hair-like), HAIRY-AWN MUHLY, LONG-AWN HAIR GRASS, SLEN-
DER MUHLY, HAIR GRASS. Densely tufted perennial without rhizomes; culms erect, 60–100(–150)
cm tall; leaf sheaths rounded, the basal ones often fibrous but not extensively so; ligule 1.8–8
(–10) mm long; panicles open, diffuse, 15–40(–60) cm long, 5–30(–40) cm wide, the branches
and pedicels capillary and widely spreading at maturity; spikelets usually (2.6–)3–4.5(–5) mm
long; glume body � 1/2 as long as lemma body; upper glume usually with awn 0.5–5 mm long;
lemma occasionally with setaceous teeth to ca. 2 mm long, with variable awn (0–)2–15(–18)
mm long. Sandy or rocky forests, openings; widespread in East TX; also Gulf Prairies and
Marshes, scattered in the Cross Timbers and Prairies, and w to Taylor Co. (Peterson 2003b;
Turner et al. 2003); e U.S. from MA s to FL w to KS and TX. Aug–Nov. This species is grown as an
ornamental (Peterson 2003b).
Muhlenbergia dubia E. Fourn., (doubtful), PINE MUHLY, PINELAND MUHLY. Densely tufted perennial
without rhizomes; culms erect, 30–100 cm tall; leaf sheaths rounded; ligule 4–10 mm long;
panicle 10–40 cm long, to 2.4 cm wide, contracted, densely-flowered, the branches with flowers
to base; spikelets (3.8–)4–5 mm long; lemma glabrous proximally, scabrous distally, awnless or
with awn to 6 mm long. Slopes, rock outcrops; Travis Co. (M.C. Johnston 12442 (TAES, TEX);
Denny 2003) near w margin of East TX; since this species was added after map pages for the
flora were completed, no county distribution map is provided; mainly Trans-Pecos but also