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.

Pseudosorghum zollingeri

HABIT Annual. Culms decumbent; 40–90 cm long; rooting from lower nodes. Ligule an eciliate membrane; 1.5–2 mm long. Leaf-blades 30–40 cm long; 6–10 mm wide. Leaf-blade surface pubescent. Leaf-blade margins spinulose. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme.

Panicle open; oblong; dense; 8–10 cm long.

Racemes 3.5–4 cm long; bearing 10–14 fertile spikelets on each. Rhachis fragile at the nodes; ciliate on margins. Rhachis internodes filiform. Rhachis internode tip transverse.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform; 3 mm long; without a translucent median line; ciliate; tip rectangular.

STERILE SPIKELETS Companion sterile spikelets well-developed; male; linear, or lanceolate; 4–5 mm long; as long as fertile; separately deciduous. Companion sterile spikelet glumes herbaceous; 9 -veined; glabrous; truncate. Companion sterile spikelet lemmas 2; enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; 4–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; attached transversely. Spikelet callus hairs white; 1–2 mm long.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma; shiny. Lower glume lanceolate; 1 length of spikelet; cartilaginous; without keels; 7–9 -veined. Lower glume surface flat; glabrous. Lower glume apex truncate. Upper glume elliptic; cartilaginous; without keels; keel-less except near apex; 5 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea. Lemma of lower sterile floret lanceolate; 3.5–4.5 mm long; 0.9 length of spikelet; hyaline; 0 -veined; without midvein; without lateral veins; eciliate on margins, or ciliolate on margins; acute, or acuminate. Fertile lemma oblong; 2–2.5 mm long; hyaline. Lemma apex lobed; 2 -fid; incised 0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate; 15–24 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Lodicules 2; glabrous. Anthers 3; 1.5 mm long.

DISTRIBUTION Asia-tropical: Indo-China and Malesia.

NOTES Andropogoneae. Lecomte.

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