Rytidosperma horrens

HABIT Perennial; caespitose. Butt sheaths persistent and investing base of culm; with compacted dead sheaths. Basal innovations intravaginal. Culms erect; 6–12 cm long. Culm-internodes distally glabrous. Leaf-sheaths 1–1.5 cm long; ribbed; glabrous on surface. Leaf-sheath oral hairs ciliate; 1–1.5 mm long. Ligule a fringe of hairs; 0.25 mm long. Leaf-blades deciduous at the ligule; filiform; 2.5–3 cm long; 0.5 mm wide. Leaf-blade surface scaberulous; rough adaxially.

INFLORESCENCE Inflorescence a panicle, or composed of racemes; comprising 2–5 fertile spikelets. Peduncle 4–6 cm long.

Racemes 1; single; 1–1.7 cm long. Rhachis scaberulous on margins.

Spikelets solitary. Fertile spikelets pedicelled. Pedicels 2–5 mm long; scaberulous.

FERTILE SPIKELETS Spikelets comprising 3–5 fertile florets; with diminished florets at the apex. Spikelets lanceolate; laterally compressed; 6–8 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 0.3–0.5 mm long; glabrous. Floret callus 0.25 mm long; pilose; obtuse. Floret callus hairs 0.4–0.6 mm long.

GLUMES Glumes persistent; similar; shorter than spikelet; thinner than fertile lemma. Lower glume ovate; 5–6 mm long; 1 length of upper glume; membranous; much thinner on margins; without keels; 3 -veined. Lower glume lateral veins meeting at apex. Lower glume surface puberulous; hairy above. Lower glume apex acute. Upper glume ovate; 5–6 mm long; membranous; without keels; 5 -veined. Upper glume lateral veins meeting at apex. Upper glume surface puberulous; hairy above. Upper glume apex acute.

FLORETS Fertile lemma ovate; 3.5–4.5 mm long; chartaceous; without keel; 7 -veined. Lemma lateral veins meeting above. Lemma surface with marginal hair tufts; bearing 4 hair tufts in all. Lemma hairs 0.5–0.75 mm long. Lemma apex dentate; 2 -fid; with lobes 1.5–2.5 mm long; awned; 3 -awned. Principal lemma awn from a sinus; geniculate; reflexed; 1.5–2.5 mm long overall; with twisted column. Lateral lemma awns arising on apex of lobes; 1–1.5 mm long. Palea 2.5 mm long. Palea keels ciliate; adorned above. Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2; cuneate; 0.4–0.5 mm long; fleshy; veined; ciliate. Anthers 3; 0.7–1 mm long; yellow; anther tip apiculate.

FRUIT Caryopsis with adherent pericarp; obovoid; 1.4–1.5 mm long. Embryo 0.75 length of caryopsis. Hilum elliptic.

DISTRIBUTION Australasia: New Zealand.

NOTES Arundineae. Connor & Molloy 2007.

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