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Descriptions

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

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

Ammochloa

HABIT Annual. Culms geniculately ascending (1/1), or decumbent (1/1); 0.5–7.916–25 cm long. Ligule an eciliate membrane, or absent (1). Leaf-blade margins cartilaginous (1/1).

INFLORESCENCE Inflorescence a panicle; not deciduous as a whole (2), or deciduous as a whole (1); subtended by an unspecialized leaf-sheath (2), or a spatheole (1); exserted (2), or embraced at base by subtending leaf (1). Spatheole lanceolate (1/1); herbaceous (1/1). Peduncle persistent (2), or disarticulating (1).

Panicle capitate.

Spikelets solitary. Fertile spikelets sessile (2), or pedicelled (1). Pedicels oblong (1/1).

STERILE SPIKELETS Basal sterile spikelets absent (2), or well-developed (1).

FERTILE SPIKELETS Spikelets comprising 1–6 fertile florets (1), or 7–10 fertile florets (2), or 11–14 fertile florets (1); with a barren rhachilla extension (1), or with diminished florets at the apex (2). Spikelets oblong; laterally compressed; 5–8–15 mm long; falling entire (1), or breaking up at maturity (2); deciduous with accessory branch structures (1/1); disarticulating below each fertile floret (1/2), or above glumes but not between florets (1/2). Rhachilla internodes definite.

GLUMES Glumes persistent (2/2); shorter than spikelet; thinner than fertile lemma (2), or similar to fertile lemma in texture (1). Lower glume lanceolate (1), or ovate (2); 1 times length of upper glume; membranous (1), or scarious (2); without keels (1), or 1-keeled (2); wingless (1), or winged on keel (2); 1 -veined (2), or 5 -veined (1). Lower glume lateral veins absent (2), or distinct (1). Lower glume surface without pits. Lower glume apex obtuse (1), or acute; muticous (2), or mucronate (1). Upper glume lanceolate (1), or ovate (2); 0.5–0.825–1 times length of adjacent fertile lemma; membranous (1), or scarious (2); with undifferentiated margins (1), or hyaline margins (2); without keels (1), or 1-keeled (2); wingless (1), or winged on keel (2); 1 -veined (2), or 5 -veined (1). Upper glume apex obtuse (1), or acute; muticous (2), or mucronate (1).

FLORETS Fertile lemma elliptic (1), or ovate (2); membranous (1), or chartaceous (2), or coriaceous (1); of similar consistency on margins (1), or much thinner on margins (2); without keel; wingless; 5 -veined, or 6–7 -veined (2), or 8–9 -veined (1). Lemma surface smooth, or scabrous (1); unwrinkled; without grooves; glabrous (2), or pubescent (1), or pilose (1); with simple hairs (1/2), or capitate hairs (1/2). Lemma apex entire, or dentate (1); 2 -fid (1/1); emarginate (1), or obtuse (1), or acute (1); muticous (1), or mucronate (2), or awned (1); 1 -awned (1/1). Principal lemma awn apical (2), or from a sinus (1). Palea 0.9–0.95–1 times length of lemma; 2 -veined (2/2). Palea keels smooth (2), or scaberulous (1); eciliate (2), or ciliolate (1). Apical sterile florets resembling fertile though underdeveloped (2/2).

FLOWER Lodicules absent. Anthers 3. Stigmas 2 (1/1); plumose (2), or pubescent (1). Ovary unappendaged (1), or beaked (2); glabrous (1/1).

FRUIT Caryopsis with adherent pericarp; ellipsoid (2), or oblong (1); plano-convex (1/2), or trigonous (1/2); apex rostrate. Embryo 0.33–0.365–0.4 times length of caryopsis. Hilum punctiform.

DISTRIBUTION Europe (1), or Africa, or Temperate Asia (1).

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Version: 8th November 2006.

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