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.

Paractaenum novae-hollandiae

HABIT Annual; caespitose. Culms erect, or decumbent; 30–60 cm long. Ligule a ciliolate membrane; 2–3 mm long. Leaf-blades 3–10 cm long; 2–6 mm wide; flaccid.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 3–12; borne along a central axis; deflexed, or spreading; unilateral; 1–6 cm long; bearing few fertile spikelets; bearing 1–4 fertile spikelets on each. Central inflorescence axis 5–12 cm long; flattened. Rhachis deciduous from axis; narrowly winged; angular; scabrous on margins; terminating in a barren extension; extension subulate. Spikelet packing abaxial; distant. Raceme-bases cuneate; 3–7 mm long.

Spikelets appressed; subtended by an involucre. Fertile spikelets pedicelled; 1 in the cluster. Involucre composed of bristles; 3.5–10 mm long. Involucral bristles deciduous with the fertile spikelets; few; 1 per spikelet (absent from distal spikelets); antrorsely scaberulous. Pedicels oblong; 0.5 mm long.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets oblong; dorsally compressed; obtuse; 3.5–5 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes dissimilar; reaching apex of florets; thinner than fertile lemma. Lower glume ovate; 0.5 length of spikelet; membranous; without keels; 3–7 -veined. Lower glume apex truncate, or obtuse. Upper glume ovate; membranous; without keels; 11 -veined. Upper glume apex acute.

FLORETS Basal sterile florets barren; with palea, or without significant palea. Lemma of lower sterile floret similar to upper glume; ovate; 1 length of spikelet; membranous; 9–11 -veined; acute. Fertile lemma elliptic; 4 mm long; coriaceous; without keel. Lemma surface striate, or punctate. Lemma margins involute. Palea coriaceous.

FLOWER Lodicules 2; cuneate; 0.6 mm long; fleshy; truncate. Anthers 3; 1.75 mm long.

DISTRIBUTION Australasia: Australia.

NOTES Paniceae. Vickery.

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