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Descriptions

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

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

Phyllorachis sagittata

HABIT Perennial; caespitose. Cataphylls evident. Culms decumbent; 60–120 cm long. Culm-internodes retrorsely scabrous. Culm-nodes glabrous, or pubescent. Ligule a ciliolate membrane. Leaf-blade base sagittate; with a brief petiole-like connection to sheath. Leaf-blades lanceolate; 4–14 cm long; 15–25 mm wide. Leaf-blade venation with obscure cross veins. Leaf-blade apex acute.

INFLORESCENCE Monoecious; with male and female spikelets in the same inflorescence. Inflorescence composed of racemes; terminal and axillary. Axillary inflorescences present in upper axils; different from terminal (short, with large female spikelet).

Racemes 4–20; borne along a central axis; in a unilateral false spike; appressed; lanceolate; 0.7–0.9 cm long; bearing few fertile spikelets; bearing 1 fertile spikelets on each. Central inflorescence axis 4–12 cm long; foliaceous (5–9 mm wide); tip subulate. Rhachis deciduous from axis; broadly winged; 2–3 mm wide; terminating in a barren extension; extension flattened.

Sexes segregated; on bisexual branches; with male above. Spikelets in threes. Fertile spikelets sessile; 1 in the cluster. Male spikelets sessile; 2 in a cluster.

STERILE SPIKELETS Apical sterile spikelets absent, or rudimentary; 0–2 in number.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets ovate; laterally compressed; compressed slightly; gibbous; 10–16 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; shorter than spikelet; thinner than fertile lemma. Lower glume subulate; 1 mm long; 0.05–0.1 length of spikelet. Upper glume oblong; 0.3–0.5 length of adjacent fertile lemma; membranous; 1-keeled; 5–9 -veined. Upper glume margins ciliolate. Upper glume apex acute.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret ovate; 1 length of spikelet; coriaceous; 15 -veined; sulcate (rugose in groove); scabrous; rough above; ciliolate on margins; acute. Fertile florets female. Fertile lemma ovate; 10–16 mm long; chartaceous; keeled; 11–17 -veined. Lemma margins involute. Lemma apex caudate. Palea lanceolate; 1 length of lemma; chartaceous; 8–12 -veined.

FLOWER Lodicules 2; obovate; 1.5 mm long; membranous. Anthers 6. Stigmas 2; terminally exserted.

FRUIT Caryopsis with adherent pericarp; linear; laterally compressed; biconvex; sulcate on hilar side; 6 mm long. Hilum punctiform.

MALE Male spikelets similar to female but less developed; 7–8 mm long. Male spikelet glumes 2. Male spikelet lemma 3–5 -veined.

DISTRIBUTION Africa: west-central tropical, east tropical, and southern tropical.

NOTES Phyllorachideae. FTEA.

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