Tuctoria mucronata

HABIT Annual; caespitose. Culms geniculately ascending, or decumbent; 6–12 cm long; disarticulating at the nodes. Culm-internodes solid. Leaves without demarcation between sheath and blade. Leaf-sheaths viscid. Ligule absent. Leaf-blades involute; 2–4 cm long; 1–2 mm wide; viscid; aromatic. Leaf-blade surface pubescent, or pilose.

INFLORESCENCE Inflorescence composed of racemes; embraced at base by subtending leaf.

Racemes 1; single; multilateral; 1.5–6 cm long. Rhachis angular. Spikelet packing broadside to rhachis.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 5–10 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–12 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 4–7 mm long; 1 length of upper glume; chartaceous; without keels; 7 -veined. Lower glume apex entire, or with a unilateral tooth, or dentate; 1–2 -fid; acute; mucronate. Upper glume oblong; 4–7 mm long; 1 length of adjacent fertile lemma; chartaceous; without keels; 7–9 -veined. Upper glume apex entire, or with a unilateral tooth, or dentate; 1–2 -fid; acute; mucronate.

FLORETS Fertile lemma oblong; 5–7 mm long; chartaceous; keeled; 11–15 -veined. Lemma lateral veins ribbed. Lemma surface scaberulous; rough on veins. Lemma apex erose; acute; mucronate. Palea 1 length of lemma; 2 -veined. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; adnate to palea; cuneate; 0.5 mm long; fleshy; truncate. Anthers 3; 3 mm long; yellow. Stigmas 2; sparsely hairy.

FRUIT Caryopsis with adherent pericarp; oblong; laterally compressed; 3 mm long; dark brown; smooth. Embryo 0.75 length of caryopsis.

DISTRIBUTION North America: southwest USA.

NOTES Orcuttieae. Reeder.

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