Cryptochloa decumbens

HABIT Perennial. Culms decumbent; 15–30 cm long; rooting from lower nodes. Culm-internodes hollow. Culm-nodes constricted; pubescent. Lateral branches ample. Leaves cauline; 4–6 per branch; distichous. Leaf-sheaths keeled; outer margin hairy. Ligule a ciliolate membrane; 0.9–1.5 mm long; pubescent on abaxial surface. Leaf-blade base asymmetrical; with a brief petiole-like connection to sheath; petiole 0.1 cm long; petiole pubescent. Leaf-blades lanceolate, or oblong; 1.8–2.1 cm long; 6–7 mm wide; mid-green and purple; discolorous with last colour beneath (purple below). Leaf-blade surface scabrous; glabrous to pubescent; hairy on both sides. Leaf-blade margins scabrous. Leaf-blade apex abruptly acute; apiculate.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Inflorescence comprising only a few spikelets; comprising 2 fertile spikelets (and 1 male); axillary; embraced at base by subtending leaf. Axillary inflorescences present in lower axils.

Sexes segregated; with male below. Spikelets in threes. Fertile spikelets pedicelled; 2 in the cluster. Male spikelets pedicelled; 1 in a cluster. Pedicels clavate (female), or linear (male); unequal (male intermediate in length); scabrous.

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 7.6–8.5 mm long; 1.8–2 mm wide; breaking up at maturity; disarticulating below each fertile floret. Floret callus evident; 1 mm long.

GLUMES Glumes deciduous; similar; exceeding apex of florets; thinner than fertile lemma. Lower glume lanceolate; 7.6–8.5 mm long; 1 length of upper glume; membranous; mid-green, or purple; without keels; 5 -veined. Lower glume lateral veins obscure; with cross-veins. Lower glume surface scabrous; rough at apex. Lower glume apex acuminate. Upper glume lanceolate; 7.4–8.2 mm long; 1.2–1.3 length of adjacent fertile lemma; membranous; mid-green, or purple; without keels; 5–7 -veined. Upper glume lateral veins with cross-veins. Upper glume surface scabrous; rough at apex. Upper glume apex acuminate.

FLORETS Fertile florets female. Fertile lemma lanceolate; 6–6.2 mm long; 1.6–1.9 mm wide; indurate; pallid; shiny; without keel. Lemma surface papillose. Lemma margins involute. Lemma apex acute. Palea 1 length of lemma; indurate. Palea surface papillose.

FLOWER Lodicules 3; 1.3 mm long; membranous. Anthers 3; 1.1 mm long. Stigmas 2.

FRUIT Caryopsis fusiform; 4.2–4.4 mm long; light brown. Embryo 0.2 length of caryopsis. Hilum linear; 1 length of caryopsis.

MALE Male spikelets distinct from female; 1 flowered; separately deciduous; oblong; 3 mm long; glabrous. Male spikelet glumes absent. Male spikelet lemma 3 -veined; muticous.

DISTRIBUTION South America: Mesoamericana.

NOTES Olyreae. Soderstrom.

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