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).

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