GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Gerritea pseudopetiolata

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with compacted dead sheaths, or fibrous dead sheaths. Culms decumbent; 60–120 cm long. Culm-internodes terete; 4–9 cm long; mid-green, or purple; distally pilose. Lateral branches ample; arising from upper culm. Leaves cauline. Leaf-sheaths 4–17 cm long; longer than adjacent culm internode; glabrous on surface, or pilose; with tubercle-based hairs; outer margin hairy. Leaf-sheath oral hairs ciliate. Ligule a ciliolate membrane; 0.3–0.6 mm long; pilose on abaxial surface. Collar glabrous, or pubescent. Leaf-blade base with a false petiole; petiole 1–2 cm long. Leaf-blades deciduous at the ligule; linear, or lanceolate; 11–27 cm long; 7–15 mm wide. Leaf-blade surface pilose; sparsely hairy. Leaf-blade margins scaberulous; glabrous, or ciliate; hairy at base. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle. Peduncle 5–10 cm long.

Panicle open; pyramidal; effuse; 14–30 cm long; 4–12 cm wide. Primary panicle branches ascending, or spreading. Panicle axis hispid. Panicle branches capillary; scabrous; hispid; pubescent in axils.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform; terete; flexuous; 4–8 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets elliptic; laterally compressed; compressed slightly; 1.8–2.2 mm long; 0.5 mm wide; falling entire; readily shedding fertile florets. Rhachilla internodes elongated between glumes.

GLUMES Glumes similar; reaching apex of florets; thinner than fertile lemma; gaping. Lower glume lanceolate; 1.4–1.9 mm long; 0.75–1 length of spikelet; 3 -veined. Lower glume margins tuberculately ciliate. Lower glume hairs 5–7 mm long. Lower glume apex acuminate. Upper glume lanceolate; 1.8–2 mm long; 1 length of spikelet; herbaceous; without keels; 3 -veined. Upper glume margins tuberculate; villous. Upper glume hairs 5–7 mm long. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret lanceolate; 1.6–1.7 mm long; 1 length of spikelet; membranous; 3 -veined; glabrous; acute. Palea of lower sterile floret 0.7–1 mm long. Fertile lemma elliptic; 1.3–1.5 mm long; 0.4 mm wide; membranous; pallid; without keel; 3 -veined. Lemma margins flat. Lemma apex acute. Palea separating from lemma above; 1 length of lemma; membranous; 2 -veined.

FLOWER Lodicules 2; 0.2 mm long; truncate. Anthers 3; 0.6–0.7 mm long.

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America: western South America.

NOTES Paniceae. Zuloaga 1997.

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