|Mary E. Barkworth|
Plants perennial; cespitose,
sometimes stoloniferous. Culms to 150 cm, herbaceous, solid,
open, rounded; ligules membranous, ciliate, cilia longer than the
membranous base, conspicuous tufts of stiff hairs present on either side
of the ligules;
blades linear, flat or folded. Inflorescences terminal, panicles
of non-disarticulating spikelike branches, exceeding the leaves; branches in
1 or more whorl(s), spikelets in 2 rows on the abaxial side of the branches,
axes terminating in a functional spikelet. Spikelets laterally
compressed, with 2-5 florets, lowest 1-2 florets bisexual, distal 1-3
florets progressively reduced and sterile; disarticulation above
the glumes, all the florets falling as a unit. Glumes much shorter
than the spikelets, membranous; lower
glumes linear, acuminate; upper glumeslanceolate-ovate, awned; calluses
bearded; lowest lemmas linear-lanceolate, 3-veined, veins prolonged
into 3 awns; central awns 8-12 mm; lateral awns 0.5-12 mm; paleas
2-keeled, acute; distal floret(s) 1-3-awned; lodicules 2; anthers
2 or 3. Caryopses sulcate; embryos 1/2 as long as the
hila punctate. x = 10. Name from the Latin tri, three,
and the genus Chloris, referring to the 3-awned lemmas and the
resemblance to Chloris.
Trichloris has two species, both of which are native to the Flora region. It differs from Chloris in its 3-awned lemmas. Both species of Trichloris have a disjunct distribution, populations in North America being widely separated from those in South America.
|Lowest lemma awns subequal, the central awns 8-12 mm long, equaling or slightly longer than the lateral awns ..... 1. T. crinita|
Lowest lemma awns unequal, the central awns 8-12 mm long, the lateral awns 0.5-1.5 mm long ..... 2. T. pluriflora
1. Trichloris crinita (Lag.) Parodi
Plants perennial; cespitose, sometimes stoloniferous. Culms to 100 cm. Sheaths glabrous or sparsely hirsute; ligules to 3 mm; blades to 20 cm long, 5-10 mm wide, scabrous. Panicles with 6-20 branches in several closely-spaced whorls, appearing as a single terminal cluster; branches to 15 cm, erect, with 7-9 spikelets per cm. Spikelets with 1 bisexual and 1(2) sterile floret(s). Lower glumes 0.8-1.1 mm; upper glumes 2-2.5 mm, awned, awns to 2 mm; lowest lemmas 2.4-3.8 mm long, about 0.5 mm wide, dorsally compressed, narrowly lanceolate to elliptic, scabrous, particularly distally, apices bilobed and 3-awned, central awns 8-12 mm, equaling or slightly longer than the 5-12 mm lateral awns; first sterile florets 1-1.5 mm, narrowing to 3 subequal 5-7 mm awns; second sterile florets, if present, similar but smaller. Caryopses 1.7-2.3 mm, strongly dorsally flattened. 2n = 40.
Trichloris crinita is a native species that grows in the southwestern United States and northern Mexico, and, as a disjunct, in northern Argentina.
2. Trichloris pluriflora E. Fourn.
Multiflower False Rhodesgrass
Plants perennial; stoloniferous or cespitose. Culms to 150 cm. Sheaths glabrous or sparsely hirsute; ligules to 3 mm; blades to 30 cm long, to 10 mm wide, scabrous or sparsely hirsute. Panicles with 7-20 branches in a few, evidently separate whorls; branches to 20 cm, ascending, with 7-9 spikelets per cm. Spikelets with 1-2 bisexual florets, a third floret with a rudimentary pistil and stamens sometimes present below the (1)2-3 sterile florets. Lower glumes 2-3 mm; upper glumes 3-5 mm; lowest lemmas 3-5 mm, mostly glabrous, margins short-ciliate near the middle, sparsely scabrous distally, apices 3-awned, central awns 8-12 mm, lateral awns 0.5-1.5 mm; lowest sterile florets 1.5-3 mm long, about 0.3 mm wide, mostly glabrous, margins sometimes short-ciliate near the middle, apices 3-awned, central awns to 8 mm, lateral awns 0.2-1 mm. Caryopses 1.8-2.2 mm, strongly dorsally compressed. 2n = 80.
Trichloris pluriflora is native from southern Texas to Guatemala and, as a disjunct, from Ecuador to Argentina.