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.

Didymogonyx

HABIT Perennial. Rhizomes short; pachymorph. Culms erect (1/1); 800–1150–1500 cm long; woody. Culm-internodes alternately elongated and bunched (1/1); terete. Lateral branches dendroid. Branch complement in a clump; subtended by a bare patch above the node; with subequal branches. Culm-sheaths persistent (1/1); auriculate (1/1). Culm-sheath blade ovate (1/1). Ligule absent. Leaf-blade base with a brief petiole-like connection to sheath. Leaf-blades linear (1), or lanceolate (1).

INFLORESCENCE Inflorescence a panicle (1), or composed of racemes (1).

Racemes single (1/1); bearing 9–25 fertile spikelets on each (1/1). Rhachis semiterete (1/1).

Spikelets solitary (1), or in pairs (1). Fertile spikelets sessile (1), or pedicelled (1).

FERTILE SPIKELETS Spikelets comprising 0 basal sterile florets (1), or 1 basal sterile florets; 5–6 fertile florets, or 7–12 fertile florets (1); with diminished florets at the apex. Spikelets oblong; laterally compressed; 12.45–50.11–120 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite.

GLUMES Glumes two (1), or several (1); persistent; shorter than spikelet. Lower glume linear (1), or oblong (1), or ovate (1); chartaceous; without keels (1/1), or 1-keeled (1/1); 1 -veined, or 2–3 -veined (1). Lower glume lateral veins absent, or distinct (1). Lower glume surface without pits. Lower glume apex obtuse (1/1), or acute (1/1), or acuminate (1/1). Upper glume lanceolate (1), or oblong (1), or ovate (1); 1-keeled (1/1); 3 -veined (1), or 5–7 -veined (1). Upper glume apex obtuse (1/1); muticous (1), or mucronate (1).

FLORETS Basal sterile florets barren; with palea (1), or without significant palea. Lemma of lower sterile floret lanceolate (1/1); 5 -veined (1/1); mucronate (1/1). Fertile lemma lanceolate (1), or ovate (1); chartaceous; without keel; wingless; 5 -veined (1), or 13–17 -veined (1). Lemma surface unwrinkled; without grooves. Lemma apex acute; muticous (1), or mucronate (1). Palea 0.5–0.75–1 length of lemma. Palea keels smooth (1), or scabrous (1); eciliate (1), or ciliolate (1). Palea surface glabrous, or puberulous (1). Palea apex dentate (1/1). Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 3; glabrous (1), or ciliate (1). Anthers 3. Stigmas 2 (1/1). Ovary unappendaged (1), or umbonate (1); glabrous (1/1).

FRUIT Caryopsis with adherent pericarp.

DISTRIBUTION South America.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.