GrassBase - The Online World Grass Flora


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

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

Panicum hirticaule

HABIT Annual; caespitose. Culms erect, or geniculately ascending, or decumbent; 25–80 cm long; 1–2.5 mm diam.; rooting from lower nodes. Culm-internodes distally glabrous, or hispid; with tubercle-based hairs. Culm-nodes pubescent. Lateral branches ample; arising from lower culm and mid culm. Leaf-sheaths hispid; with tubercle-based hairs. Ligule a ciliate membrane; 1.5–2.5 mm long. Leaf-blades 7–27 cm long; 6–15 mm wide. Leaf-blade surface glabrous, or pilose; with tubercle-based hairs.

INFLORESCENCE Inflorescence a panicle. Peduncle pubescent above.

Panicle open; ovate; 13–35 cm long. Primary panicle branches 6–13 cm long. Panicle branches straight.

Spikelets appressed; solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; dorsally compressed; acute; 2.4–2.5 mm long; falling entire.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 1.2–1.5 mm long; 0.5–0.66 length of spikelet; membranous; without keels; 3–5 -veined. Lower glume apex acute. Upper glume ovate; 2.1–2.2 mm long; 1 length of spikelet; membranous; without keels; 7 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea. Lemma of lower sterile floret similar to upper glume; ovate; 2.2–2.4 mm long; 1 length of spikelet; membranous; 9 -veined; acute. Palea of lower sterile floret 0.33 length of lemma. Fertile lemma elliptic; dorsally compressed; 1.5–1.8 mm long; indurate; shiny; without keel. Lemma margins involute. Palea involute; indurate.

FLOWER Anthers 3; 0.9–1 mm long; orange.

FRUIT Caryopsis with adherent pericarp; ellipsoid; 1.3–1.4 mm long; pallid.

DISTRIBUTION North America: southwest USA, south-central USA, and Mexico. South America: Mesoamericana, Caribbean, northern South America, western South America, Brazil, and southern South America.

NOTES Paniceae. Fl Costa Rica 1994.

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