16. Panicum linearifolium Scribn.
Pl. 168 e,
f; Map 677
P. linearifolium var. werneri (Scribn.) Fernald
P. perlongum Nash
Dichanthelium linearifolium (Scribn.) Gould
D. linearifolium var. werneri (Scribn.) Mohlenbr.
D. perlongum (Nash) Freckmann
Plants perennial, without rhizomes,
forming dense tufts. Flowering stems 10–50 cm long, erect or nearly so, unbranched or
becoming branched during the summer and autumn, the nodes and internodes
glabrous or short‑hairy, especially toward the base. Foliage mostly
crowded toward the base of the plant (due to the very much shortened internodes
toward the bases of the flowering stems), the leaves above the bases of the
flowering stems few or none (sometimes small fascicles of leaves produced on
the middle nodes during the summer and autumn), bright green to bluish green.
Leaf sheaths usually long‑hairy, the ligule 0.5–1.0 mm long, a line or
band of hairs. Leaf blades 6–20 cm long, 1–5 mm wide, mostly more than 20 times
as long as wide, mostly erect, linear to narrowly lanceolate, narrowed or
somewhat rounded at the base, relatively thick and firm, glabrous or more
commonly long‑hairy. Inflorescences 3–8 cm long, the earlier ones larger
than the later ones, the branches strongly ascending, mostly rebranched 1 or more
times, not spikelike or 1‑sided, the spikelets appearing mostly long‑stalked
at the tips of the branches. Spikelets 1.7–3.2 mm long,
elliptic in outline. Lower glume 0.6–1.6 mm long, 1/2–1/3 as long as the
spikelet, broadly ovate, rounded to bluntly or less commonly sharply pointed at
the tip, glabrous, nerveless or faintly 1‑ or 3‑nerved. Upper glume 1.7–3.2 mm long, elliptic, rounded or bluntly pointed
at the tip and not extended past the fertile floret or beaked, strongly 7‑
or 9‑nerved, glabrous or minutely hairy. Lowermost floret usually
sterile and with a reduced, inconspicuous palea, the lemma 1.7–3.2 mm long,
elliptic, rounded or bluntly pointed at the tip and not extended past the
fertile floret or beaked, strongly 7‑ or 9‑nerved, glabrous or minutely
hairy. Fertile floret 1.5–3.0 mm long, oblong‑elliptic,
rounded or with a short point at the tip. Anthers
0.3–1.5 mm long. 2n=18. May–August (vernal),
July–October (autumnal).
Scattered nearly throughout Missouri,
but apparently absent from the Mississippi Lowlands Division (eastern U.S. and adjacent Canada
west to North Dakota and Texas). Upland prairies, glades, savannas,
and openings of mesic to dry upland forests, on acidic substrates; also
roadsides and dry, disturbed areas.
For a discussion of a hybrid between P. linearifolium
and P. dichotomum, see the treatment of that species.