2. Eleusine tristachya (Lam.) Lam.
Map 588
Plants perennial, forming tufts or small clumps. Flowering
stems 5–25(–35) cm long. Leaf blades 2–15 cm long, 2–4 mm wide. Inflorescences
with 1–3 stout spikes, these 1.5–4.5 cm long, 7–15 mm wide, loosely ascending
to spreading, straight. Spikelets with 5–12 florets. Lower glume 1.5–2.5 mm
long, oblong‑lanceolate. Upper glume 2.5–4.0 mm long, narrowly oblong‑ovate.
Lemmas 3.5–5.0 mm long. Fruits black. 2n=18. July–October.
Introduced, known only from a single historical collection
from St. Louis County (native of South America; introduced in Africa and rarely
in the western and southeastern U.S.). Roadsides, railroads.