Trisetopsis elongata (Hochst. ex A.Rich.) Röser & A.Wölk

Gramineae, W. D. Clayton. Flora of West Tropical Africa 3:2. 1972

Morphology General Habit

Perennial up to 1·5 m. high.

Morphology General Habit

Perennial; caespitose. Butt sheaths dark brown. Culms erect, or decumbent; 45-150 cm long. Leaves mostly basal. Ligule an eciliate membrane; 2-4 mm long. Leaf-blades 15-45 cm long; 2-5 mm wide. Leaf-blade venation distinct. Leaf-blade surface glabrous, or pilose; sparsely hairy.

Morphology Reproductive morphology Inflorescences

Inflorescence a panicle. Panicle open; linear, or oblong; dense, or loose; equilateral, or nodding; 10-35 cm long. Primary panicle branches appressed, or ascending. Panicle branches scaberulous. Spikelets solitary. Fertile spikelets pedicelled.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 2-3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 8-14 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; pilose. Floret callus pilose.

Fertile

Spikelets comprising 2-3 fertile florets; with a barren rhachilla extension. Spikelets oblong; laterally compressed; 8-14 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; pilose. Floret callus pilose.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume elliptic; 5-10 mm long; 0.7-0.9 length of upper glume; membranous; 1-keeled; 3 -veined. Lower glume apex acute. Upper glume elliptic; 7-11 mm long; 1 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3-5 -veined. Upper glume apex acute.

Morphology Reproductive morphology Flowers Florets

Fertile lemma elliptic; 6.5-11 mm long; chartaceous, or cartilaginous; pallid, or purple; without keel; 7-9 -veined. Lemma surface smooth, or granulose, or scaberulous. Lemma apex dentate; 2 -fid; acute, or setaceously attenuate; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 15-20 mm long overall; with twisted column. Palea 0.6-0.8 length of lemma. Palea keels ciliolate. Rhachilla extension 0.75 length of fertile floret; pilose.

Morphology Reproductive morphology Flowers

Anthers 3; 2.5-3.5 mm long. Ovary pubescent on apex.

Morphology Reproductive morphology Fruits

Caryopsis with adherent pericarp; 3 mm long; hairy at apex. Hilum linear.

Distribution

Africa: west tropical, west-central tropical, northeast tropical, east tropical, southern tropical, and western Indian ocean. Asia-temperate: Arabia.

Reference

Aveneae. FTEA.

Diagnostic

Rhachilla hairs shorter than itself.

Gramineae, E. Launert. Flora Zambesiaca 10:1. 1971

Morphology General Habit

A caespitose perennial.

Morphology Culms

Culm 30-125(150) cm. tall, 2-5-noded, usually simple, erect or geniculately ascending, glabrous and smooth.

Morphology Leaves Leaf sheaths

Leaf-sheaths striate, smooth and usually glabrous, the lowermost persistent and often tinged with brown.

Morphology Leaves Ligules

Ligule c. 3 mm. long, rounded, entire or sometimes lacerate.

Morphology Leaves Leaf lamina

Leaf-laminae 10-40 x 0.2-0.5 cm., usually expanded, tapering to a fine point, glabrous or rarely scattered pilose.

Morphology Reproductive morphology Inflorescences

Panicle 10-38 cm. long, linear, narrowly oblong to narrowly elliptic, sometimes dense and with the branches more or less uppressed to the rhachis, but usually loose and open, erect or somewhat nodding; rhachis slender, flexuous; branches in groups of 2-4, filiform, scaberulous.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 8-14 mm. long, 2-3-flowered, green or purplish.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes firmly membranous, with the margins hyaline, acute to acuminate, usually not much shorter than the lowermost lemma; the inferior 5-10 mm. long, lanceolate-oblong, 2-3-nerved; the superior 6.5-10.5 mm. long, narrowly elliptic, 3-5-nerved.

Morphology Reproductive morphology Inflorescences Bracts Lemma

Lemmas up to 11 mm. long, chartaceous to subcartilaginous, pale green often tinged with purple, dorsally verruculose or scabrous, the 2 apical lobes either acute or drawn out into fine bristles; awn inserted dorsally around the middle, up to 20 mm. long, geniculate and twisted beneath the bend.

Morphology Reproductive morphology Inflorescences Bracts Palea

Paleas 2/3-4/5 the length of the lemmas, narrowly oblong, with the keels ciliolate.

Morphology Reproductive morphology Flowers Androecium Stamens Anthers

Anthers 2.5-3.5 mm. long.

Morphology Reproductive morphology Fruits

Caryopsis c. 3 mm. long.

Gramineae, W. D. Clayton, S. M. Phillips & S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit

Tufted perennial.

Morphology Culms

Culms 45–150 cm. high, erect or geniculate, the basal sheaths usually tinged with orange-brown.

Morphology Leaves

Leaf-blades 15–45 cm. long and 2–5 mm. wide, usually glabrous, prominently and closely nerved; ligule 2–4 mm. long.

Morphology Reproductive morphology Inflorescences

Panicle linear to narrowly oblong, 10–35 cm. long, often loose and nodding.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets 2–3-flowered, oblong, 8–14 mm. long, the florets shortly exserted; rhachilla-internodes 2 mm. long, densely bearded; glumes firmly membranous; lower glume oblong-lanceolate, 5–10 mm. long, 2–3-nerved; upper glume elliptic-oblong, 7–11 mm. long, 3–5-nerved; lemmas chartaceous to cartilaginous, the lower 6.5–11 mm. long (less than or equal to the upper glume), smooth, granular or scaberulous, pallid or suffused with purple, 7–9-nerved, shortly bilobed, the lobes acute or each with 1–2 nerves excurrent into fine bristles; awn from about the middle, 1.5–2 cm. long, geniculate with a twisted column.

Figures

Fig. 30.

Habitat

Open forest and upland grassland; 1800–3800 m.

Distribution

K1 K3 K4 K5 K6 T2 T3 T4 T7 T8 U1 U2 U3 Sudan Republics to Ethiopia, southwards to Rhodesia

Morphology General Habit

Perennial; caespitose; clumped densely. Rhizomes elongated. Basal innovations extravaginal. Culms 30-60 cm long; 2 -noded. Leaf-sheaths tubular for much of their length; with 0.75 of their length closed; 5-10 cm long; without keel; indistinctly veined; glabrous on surface. Ligule an eciliate membrane; 1-1.5 mm long; truncate. Leaf-blades 30-70 cm long; 2-3 mm wide. Leaf-blade venation without layer of subepidermal sclerenchyma masking vein striation. Leaf-blade surface pilose; sparsely hairy; hairy abaxially.

Morphology Reproductive morphology Inflorescences

Inflorescence a panicle. Peduncle 12-20 cm long. Panicle open; oblong; 4-8 cm long. Panicle axis scaberulous. Panicle branches scaberulous; puberulous. Spikelets solitary. Fertile spikelets pedicelled.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8-9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; pubescent. Floret callus pubescent.

Fertile

Spikelets comprising 2 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 8-9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 2 mm long; pubescent. Floret callus pubescent.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume lanceolate; 6.5-7.5 mm long; 0.9 length of upper glume; membranous; much thinner on margins; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex obtuse. Upper glume lanceolate; 8-8.5 mm long; 1 length of adjacent fertile lemma; membranous; with hyaline margins; 1-keeled; 3 -veined. Upper glume apex acute.

Morphology Reproductive morphology Flowers Florets

Fertile lemma elliptic; 8-9 mm long; cartilaginous; much thinner above; without keel; 7 -veined. Lemma surface puberulous. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn dorsal; arising 0.5 way up back of lemma; geniculate; 15 mm long overall; with a straight or slightly twisted column. Palea 6 mm long. Palea keels ciliolate. Apical sterile florets resembling fertile though underdeveloped.

Morphology Reproductive morphology Flowers

Anthers 3; 2.5 mm long. Ovary pubescent on apex.

Morphology Reproductive morphology Fruits

Caryopsis with adherent pericarp; hairy at apex.

Distribution

Africa: northeast tropical.

Reference

Aveneae. Mire 2005.