Chionochloa rigida (Raoul) Zotov

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation

Predicted extinction risk: threatened. Confidence: confident

Morphology General Habit

Perennial; caespitose; clumped densely. Butt sheaths dark brown; persistent and investing base of culm; with dead sheaths fracturing into segments. Basal innovations intravaginal; flabellate. Culms erect; 100-150 cm long. Culm-internodes distally glabrous, or hirsute. Culm-nodes glabrous. Leaves mostly basal. Leaf-sheaths 10-30 cm long; keeled; pubescent, or pilose; inner surface glabrous. Leaf-sheath oral hairs pubescent; 2 mm long. Ligule a fringe of hairs; 2 mm long. Leaf-blades deciduous with part of sheath attached; 40-80 cm long; 4-7 mm wide; coriaceous; stiff; glaucous. Leaf-blade surface scabrous; rough abaxially; glabrous; hairless except near base. Leaf-blade margins cartilaginous; ciliate; hairy at base. Leaf-blade apex attenuate.

Morphology Reproductive morphology Inflorescences

Inflorescence a panicle. Panicle open; ovate; 10-30 cm long. Panicle branches scaberulous; glabrous, or pilose; bearded in axils; with prominent pulvini. Spikelets solitary. Fertile spikelets pedicelled.

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 6-8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 15-20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5 mm long. Floret callus elongated; 1.5 mm long; bearded; disarticulating obliquely. Floret callus hairs 3.5 mm long.

Fertile

Spikelets comprising 6-8 fertile florets; with diminished florets at the apex. Spikelets oblong; laterally compressed; 15-20 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes 1.5 mm long. Floret callus elongated; 1.5 mm long; bearded; disarticulating obliquely. Floret callus hairs 3.5 mm long.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes persistent; similar; shorter than spikelet; similar to fertile lemma in texture. Lower glume lanceolate; 12-14 mm long; 0.9 length of upper glume; membranous; without keels; 1-3 -veined. Lower glume lateral veins absent, or obscure. Lower glume apex acute, or setaceously attenuate. Upper glume lanceolate; 14-16 mm long; 1.6 length of adjacent fertile lemma; membranous; without keels; 5-7 -veined. Upper glume apex acute, or setaceously attenuate.

Morphology Reproductive morphology Flowers Florets

Fertile lemma elliptic; 9-10 mm long; membranous; without keel; 7 -veined. Lemma surface pilose. Lemma margins ciliate. Lemma apex lobed; 2 -fid; with simple equal lobes, or with lateral lobes bidentate; with triangular lobes; with lobes 3 mm long; incised 0.33 of lemma length; awned; 1 -awned, or 3 -awned. Principal lemma awn from a sinus; geniculate; flat below; 10-16 mm long overall; with twisted column. Column of lemma awn 2-4 mm long. Lateral lemma awns arising on apex of lobes, or between lobes (when bidentate); 0-3.5 mm long; shorter than principal. Palea 8.5 mm long. Palea keels ciliolate. Palea surface pilose; hairy on flanks. Apical sterile florets resembling fertile though underdeveloped.

Morphology Reproductive morphology Flowers

Lodicules 2; 0.75 mm long; membranous; veined; ciliate. Anthers 4.5-5 mm long.

Morphology Reproductive morphology Fruits

Caryopsis with adherent pericarp; 3.5 mm long. Hilum linear.

Distribution

Australasia: New Zealand.

Reference

Arundineae. Connor.