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.

Duthiea

HABIT Perennial. Culms erect; 15–40–80 cm long. Ligule an eciliate membrane.

INFLORESCENCE Inflorescence composed of racemes; exserted (2), or embraced at base by subtending leaf (1).

Racemes single; erect (1), or drooping (2); unilateral; bearing few fertile spikelets; bearing 2 fertile spikelets on each (1), or 3–4 fertile spikelets on each (2), or 5–7 fertile spikelets on each (1), or 8–9 fertile spikelets on each (2), or 10–11 fertile spikelets on each (1). Rhachis subterete.

Spikelets solitary. Fertile spikelets pedicelled.

STERILE SPIKELETS Basal sterile spikelets represented by a single scale.

FERTILE SPIKELETS Spikelets comprising 1–2 fertile florets (1), or 4–5 fertile florets (1); without rhachilla extension (1), or with diminished florets at the apex (2). Spikelets linear (1), or lanceolate (1), or oblong (1), or cuneate (2); laterally compressed (2), or subterete (1); 10–16.5–22 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite (2/2); pilose (2/2). Floret callus evident; pubescent (2), or bearded (1).

GLUMES Glumes persistent; reaching apex of florets (2), or exceeding apex of florets (1); parallel to lemmas (1), or gaping (2). Lower glume elliptic; 0.9–0.9833–1 length of upper glume; herbaceous; 1-keeled; 5 -veined (2), or 6 -veined (1), or 9 -veined (1). Lower glume surface smooth (1), or asperulous (2); without pits. Lower glume apex acute. Upper glume elliptic; 1–1.066–1.1 length of adjacent fertile lemma; herbaceous; with hyaline margins; 1-keeled; 6–7 -veined (1), or 8–9 -veined (2), or 10 -veined (1). Upper glume surface smooth (1), or asperulous (2). Upper glume apex acute.

FLORETS Fertile lemma elliptic (1), or oblong (2); membranous; much thinner on margins; without keel; wingless; 7 -veined (1), or 9–11 -veined (1). Lemma surface smooth (1), or scaberulous (2); unwrinkled; without grooves; glabrous (1), or villous (2); without hair tufts (2), or with a transverse fringe of hair (1). Lemma apex dentate (1), or lobed (2); 2 -fid; incised 0.2–0.35–0.5 of lemma length; awned; 1 -awned. Principal lemma awn from a sinus; geniculate. Palea 2 -veined. Palea keels scabrous. Palea surface glabrous (1), or pilose (2). Palea apex muticous (1), or with excurrent keel veins (2). Apical sterile florets resembling fertile though underdeveloped (2/2).

FLOWER Lodicules absent. Anthers 3. Stigmas 2; papillose.

DISTRIBUTION Temperate Asia (2), or Tropical Asia.

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