Tuctoria fragilis

HABIT Annual; caespitose. Culms geniculately ascending, or decumbent; 25–50 cm long; disarticulating at the nodes. Culm-internodes solid. Leaves without demarcation between sheath and blade. Leaf-sheaths viscid. Ligule absent. Leaf-blades deciduous at the ligule; flat, or involute; 4–8 cm long; 11–12 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; 4–5 cm long. Rhachis angular. Spikelet packing broadside to rhachis.

Spikelets solitary. Fertile spikelets sessile.

FERTILE SPIKELETS Spikelets comprising 7–10 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 10–13 mm long; breaking up at maturity; disarticulating below each fertile floret.

GLUMES Glumes persistent; similar; shorter than spikelet. Lower glume ovate; 5–6 mm long; 1 length of upper glume; chartaceous; much thinner on margins; without keels; 7 -veined. Lower glume apex acute. Upper glume oblong; 5–6 mm long; 1 length of adjacent fertile lemma; chartaceous; with hyaline margins; without keels; 7–9 -veined. Upper glume apex acute.

FLORETS Fertile lemma oblong; 5–6 mm long; chartaceous; much thinner on margins; keeled; 5 -veined. Lemma lateral veins ribbed. Lemma apex entire, or erose; acute; mucronate. Palea 1 length of lemma; 2 -veined. Palea keels scaberulous. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; adnate to palea; cuneate; 0.2 mm long; fleshy; truncate. Anthers 3; 3 mm long; yellow, or purple. Stigmas 2; sparsely hairy.

FRUIT Caryopsis with adherent pericarp; obovoid; laterally compressed; 2–2.5 mm long; rugose. Embryo 0.75 length of caryopsis.

DISTRIBUTION North America: Mexico.

NOTES Orcuttieae. Reeder.

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