Setaria constricta

HABIT Perennial; caespitose. Rootstock evident. Basal innovations extravaginal. Culms erect, or geniculately ascending; 10–80 cm long; 4–5 -noded; without nodal roots, or rooting from lower nodes. Culm-internodes smooth, or scaberulous; distally glabrous, or pubescent. Culm-nodes glabrous, or pubescent. Lateral branches sparse, or ample. Leaf-sheaths keeled; smooth, or antrorsely scabrous; glabrous on surface, or pilose; with tubercle-based hairs. Ligule a fringe of hairs; 0.3–1.25 mm long. Leaf-blades 5–15 cm long; 1–3.5 mm wide. Leaf-blade surface scaberulous, or scabrous; rough adaxially; glabrous, or pilose; with tubercle-based hairs. Leaf-blade apex attenuate.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 4–19; borne along a central axis; unilateral; 1–3 cm long; bearing few fertile spikelets. Central inflorescence axis 2.5–20 cm long; pubescent; tip filiform. Rhachis angular; 0.15–0.4 mm wide; pubescent on surface; scabrous on margins; terminating in a barren extension; extension bristle-like; extension 1–6 mm long. Spikelet packing abaxial; irregular; 2 -rowed.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 0.2–1.5 mm long; tip discoid.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; dorsally compressed; plano-convex; acute; 2–3.5 mm long; falling entire. Rhachilla internodes elongated between glumes, elongated below basal sterile floret, and elongated below proximal fertile floret.

GLUMES Glumes shorter than spikelet; thinner than fertile lemma. Lower glume oblate; clasping; 0.5–0.66 length of spikelet; membranous; without keels; 3–5 -veined. Lower glume surface glabrous, or puberulous. Lower glume apex acute. Upper glume orbicular; 0.75–0.9 length of spikelet; membranous; without keels; 5–9 -veined. Upper glume apex obtuse, or acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret similar to upper glume; elliptic; 1 length of spikelet; membranous; 5 -veined; sulcate; acute. Fertile lemma elliptic; 2–3.5 mm long; indurate; without keel; 5 -veined. Lemma surface rugulose; with distinct germination flap. Lemma margins involute. Lemma apex acute. Palea reflexed at apex; indurate; 2-keeled. Palea surface rugose.

FLOWER Anthers 3.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION Australasia: Australia. Pacific: southwestern.

NOTES Paniceae. Morrone et al 2015.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.