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.

Cymbopogon

HABIT Annual (2), or perennial (52). Rhizomes absent (51), or short (2). Culms erect (38/42), or geniculately ascending (10/42), or decumbent (1/42), or rambling (1/42); robust (1/2), or slender (1/2); 15–105.4–300 cm long; firm (49), or wiry (4); without nodal roots (3/5), or with prop roots (4/5). Culm-internodes terete (1/1). Culm-nodes flush with internodes (1/4), or swollen (4/4). Leaf-sheath auricles absent, or erect (3). Ligule an eciliate membrane (52), or a ciliolate membrane (1). Leaf-blades filiform (7), or linear (52), or lanceolate (3); herbaceous (51), or coriaceous (2); firm (52), or flaccid (1); without scent (3), or aromatic (50).

INFLORESCENCE Synflorescence compound; scanty (5), or linear (33), or paniculate (22), or fasciculate (1), or globose (1). Inflorescence composed of racemes; terminal and axillary; subtended by a spatheole; exserted (3), or embraced at base by subtending leaf (2), or enclosed (48). Spatheole linear (2/41), or lanceolate (9/41), or elliptic (33/41); chartaceous (4/9), or herbaceous (5/9).

Racemes paired; erect (8), or ascending (3), or deflexed (43); bearing 2 fertile spikelets on each (1/11), or 3 fertile spikelets on each (3/11), or 4 fertile spikelets on each (5/11), or 5 fertile spikelets on each (11/11), or 6 fertile spikelets on each (8/11), or 7 fertile spikelets on each (5/11), or 8 fertile spikelets on each (4/11). Rhachis fragile at the nodes; semiterete (51/51). Rhachis internodes filiform (1), or linear (50), or clavate (2). Rhachis internode tip transverse; cupuliform. Raceme-bases brief (1), or linear (2), or flattened (50); subequal (30/52), or unequal (the longer measured) (22/52).

Spikelets ascending (1/1); in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform (1), or linear (50), or clavate (2); tip widened (1/1).

STERILE SPIKELETS Basal sterile spikelets absent (6), or represented by a single scale (1), or rudimentary (3), or well-developed (44).

Companion sterile spikelets represented by single glumes (2), or well-developed (51); deciduous with the fertile (52/52). Companion sterile spikelet glumes muticous (49/50), or pungent (1/50).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (2), or lanceolate (36), or elliptic (10), or oblong (7), or ovate (3); dorsally compressed; 2.49–4.822–9 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent (8/25), or pilose (16/25), or bearded (1/25); base obtuse; inserted.

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume linear (6), or lanceolate (32), or elliptic (8), or oblong (10), or ovate (2); membranous (5/50), or chartaceous (45/50); 2-keeled; wingless (19), or winged on keel (36). Lower glume intercarinal veins absent (27/52), or obscure (17/52), or distinct (26/52). Lower glume surface convex (1), or flat (22), or concave (25), or with V-shaped depression (13); smooth (51), or wrinkled (6), or rugose (1); without pits; glabrous (52), or puberulous (1), or pubescent (3). Lower glume apex entire (48), or dentate (5); 2 -fid (4/5), or 3 -fid (1/5); emarginate (11/17), or obtuse (1/17), or acuminate (5/17). Upper glume linear (1), or lanceolate (52); membranous (1/2), or chartaceous (1/2); 1-keeled; wingless (48), or winged on keel (5); 1–2 -veined (2/9), or 3 -veined (7/9), or 5–6 -veined (1/9), or 7 -veined (2/9). Upper glume primary vein eciliate (51), or ciliate (2). Upper glume surface glabrous (52), or pubescent (1). Upper glume apex acute, or acuminate (1).

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear (2/15), or lanceolate (9/15), or elliptic (1/15), or oblong (3/15); hyaline; 1 -veined (1/10), or 2 -veined (9/10), or 3 -veined (1/10); acute (1/1). Fertile lemma linear (3), or lanceolate (51), or oblong (1); hyaline (51/51); without keel; wingless; 1 -veined (3/3), or 2–3 -veined (1/3). Lemma surface unwrinkled; without grooves. Lemma margins eciliate (49), or ciliolate (2), or ciliate (2). Lemma apex entire (4), or dentate (5), or lobed (47); 2 -fid (52/52); incised 0.15–0.4757–0.5 of lemma length; muticous (6), or mucronate (3), or awned (50); 1 -awned (50/50). Principal lemma awn apical (3/52), or from a sinus (49/52); straight (7/52), or geniculate (46/52). Palea present (1), or absent or minute (52).

FLOWER Lodicules 2 (1/1). Anthers 3 (50/50).

FRUIT Caryopsis with adherent pericarp (30/30); ellipsoid (2/7), or orbicular (2/7), or obovoid (3/7), or oblanceolate (1/7); isodiametric (3/3).

DISTRIBUTION Africa (15), or Temperate Asia (25), or Tropical Asia (36), or Australasia (11), or Pacific (4), or North America (1), or South America (4).

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