GrassBase - The Online World Grass Flora


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

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

Arrhenatherum calderae

HABIT Perennial; caespitose; clumped densely. Culms erect; 50–100 cm long; 3–4 -noded. Ligule an eciliate membrane; 3–4 mm long; erose; truncate, or obtuse. Leaf-blades 10–20 cm long; 3–4 mm wide; glaucous. Leaf-blade surface scaberulous; rough abaxially. Leaf-blade margins scaberulous. Leaf-blade apex acuminate.

INFLORESCENCE Inflorescence a panicle.

Panicle open; linear, or lanceolate; 8–9 cm long. Primary panicle branches bearing 1–3 fertile spikelets on each lower branch.

Spikelets solitary. Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; with a barren rhachilla extension. Spikelets lanceolate; laterally compressed; 8–10 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes elongated below proximal fertile floret.

GLUMES Glumes persistent; dissimilar; reaching apex of florets; thinner than fertile lemma; shiny; gaping. Lower glume lanceolate; 6.5 mm long; 0.75 length of upper glume; membranous; 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume apex acute. Upper glume lanceolate; 6.5 mm long; 1.1 length of adjacent fertile lemma; membranous; 1-keeled; 3 -veined. Upper glume apex acute.

FLORETS Basal sterile florets male; with palea; attached to and deciduous with the fertile. Lemma of lower sterile floret ovate; 7–8 mm long; 1 length of fertile lemma; chartaceous; much thinner above; 7 -veined; dentate; 2 -fid; awned. Awn of lower sterile floret dorsal; arising 0.1 way up back of lemma; geniculate; 15–18 mm long. Palea of lower sterile floret 5 mm long. Fertile lemma lanceolate; 7–8 mm long; chartaceous; much thinner above; without keel; 7 -veined. Lemma apex dentate; 2 -fid; awned; 1 -awned. Principal lemma awn subapical; straight; 3–6 mm long overall. Palea keels ciliolate.

FLOWER Anthers 3; 4 mm long; pallid, or yellow. Ovary pubescent all over.

FRUIT Caryopsis with adherent pericarp; lanceolate; 5 mm long; hairy all over.

DISTRIBUTION Africa: Macaronesia.

NOTES Aveneae. Hansen 2001.

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