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.

Andropogon

HABIT Annual (7), or perennial (96). Rhizomes absent (97), or short (5), or elongated (4). Culms erect (43/54), or geniculately ascending (11/54), or decumbent (3/54), or rambling (3/54); robust (5/8), or slender (3/8); 5–103.8–400 cm long; firm (100), or wiry (3); without nodal roots (1/1), or with prop roots (1/1). Culm-internodes abbreviated and closely packed at the base (1/1); terete (1/1), or channelled (1/1). Culm-nodes swollen (1/1). Lateral branches lacking (7/36), or sparse (21/36), or ample (10/36), or suffrutescent (2/36). Leaf-sheath auricles absent (96), or erect (10). Ligule an eciliate membrane (65), or a ciliolate membrane (38), or a ciliate membrane (1). Leaf-blade base without a false petiole (101), or with a false petiole (3). Leaf-blades filiform (4), or linear (95), or lanceolate (5); herbaceous (102), or coriaceous (1); stiff (14), or firm (88), or flaccid (1). Leaf-blade midrib evident (2/5), or conspicuous (2/5), or widened (1/5).

INFLORESCENCE Synflorescence simple (44), or compound (63); scanty (12/57), or linear (23/57), or paniculate (22/57), or fastigiate (1/57), or fasciculate (1/57). Inflorescence a panicle with branches tipped by a raceme (1), or composed of racemes; terminal (37), or terminal and axillary (71); subtended by an unspecialized leaf-sheath (37), or an inflated leaf-sheath (1), or a spatheole (68); exserted (85), or embraced at base by subtending leaf (18), or enclosed (5). Spatheole linear (49/67), or lanceolate (22/67), or elliptic (1/67); membranous (1/8), or herbaceous (7/8), or scarious (3/8). Peduncle tipped by a glumaceous appendage (1/1).

Racemes single (13), or paired (76), or digitate (41), or borne along a central axis (1); erect (1), or ascending (100), or deflexed (2); unilateral (2/5), or bilateral (3/5); bearing few fertile spikelets (1), or many spikelets (102); bearing 2–3 fertile spikelets on each (1/5), or 4 fertile spikelets on each (2/5), or 5–6 fertile spikelets on each (3/5), or 7–10 fertile spikelets on each (2/5), or 12–25 fertile spikelets on each (1/5). Rhachis tough (1), or fragile at the nodes (102); deciduous from axis (1/1); subterete (4/6), or semiterete (2/6). Spikelet packing contiguous (100), or lax (3). Rhachis internodes filiform (35), or linear (39), or columnar (1), or oblong (3), or clavate (20), or cuneate (13), or inflated (1). Rhachis internode tip transverse (101), or oblique (2); flat (4), or cupuliform (65), or crateriform (34). Raceme-bases brief (98), or filiform (3), or linear (2), or flattened (1); subequal (3/4), or unequal (the longer measured) (1/4); unappendaged (102), or shortly lobed (1).

Spikelets squeezed between internode and pedicel (8/92), or appressed (47/92), or ascending (39/92), or spreading (7/92); in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels filiform (37), or linear (42), or oblong (2), or clavate (16), or cuneate (14), or inflated (2); tip rectangular (3/13), or widened (1/13), or cupuliform (1/13), or lobed (8/13).

STERILE SPIKELETS Basal sterile spikelets absent (99), or well-developed (4).

Companion sterile spikelets represented by barren pedicels (9), or represented by single glumes (12), or rudimentary (2), or well-developed (85); persistent (18/48), or deciduous with the fertile (1/48), or separately deciduous (29/48). Companion sterile spikelet glumes muticous (67/90), or mucronate (13/90), or awned (23/90).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (20), or lanceolate (73), or elliptic (12), or oblong (12), or ovate (1); laterally compressed (12), or subterete (1), or dorsally compressed (90); 2–5.46–16 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus brief (79), or square (8), or oblong (11), or cuneate (5), or linear (1); glabrous (9/96), or pubescent (24/96), or pilose (54/96), or bearded (9/96); base truncate (3), or obtuse (98), or acute (1), or pungent (1); attached transversely (6), or inserted (97).

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume linear (17), or lanceolate (75), or elliptic (12), or oblong (9), or ovate (1); membranous (18), or chartaceous (18), or herbaceous (3), or cartilaginous (5), or coriaceous (63); 2-keeled; wingless (95), or winged on keel (10); 2 -veined (1/11), or 4 -veined (4/11), or 5 -veined (2/11), or 6 -veined (3/11), or 7 -veined (1/11), or 14–18 -veined (2/11). Lower glume lateral veins without ribs (102), or ribbed (1); intercarinal veins absent (47/70), or obscure (3/70), or distinct (22/70). Lower glume surface convex (9), or flat (25), or concave (65), or with a longitudinal median groove (12), or grooved on either side of midvein (1), or deeply depressed (18); smooth (99), or asperulous (2), or scabrous (2); without pits (101), or pitted (1), or lacunose (1); glabrous (98), or puberulous (2), or pubescent (8), or pilose (4), or hirsute (2), or villous (2). Lower glume apex entire (82), or erose (2), or dentate (21); 2 -fid (20/20); emarginate (1/15), or obtuse (2/15), or acute (7/15), or acuminate (4/15), or attenuate (2/15), or caudate (1/15); muticous (102), or awned (1). Upper glume linear (50), or lanceolate (52), or elliptic (1), or oblong (1); membranous (38), or chartaceous (34), or coriaceous (31); 1-keeled; wingless (102), or winged on keel (1); 1 -veined (10/28), or 3 -veined (18/28), or 4–5 -veined (1/28). Upper glume primary vein eciliate (100), or ciliolate (1), or ciliate (1), or pubescent (1). Upper glume surface smooth (102), or scabrous (1); glabrous (101), or puberulous (2), or pubescent (1). Upper glume apex entire (101), or dentate (2); 2 -fid (2/2); truncate (1/13), or acute (8/13), or acuminate (5/13); muticous (80), or mucronate (8), or awned (22); 1 -awned (21/21).

FLORETS Basal sterile florets barren; with palea (2), or without significant palea (102). Lemma of lower sterile floret linear (2/101), or lanceolate (18/101), or oblong (81/101); hyaline; 0 -veined (5/69), or 1 -veined (2/69), or 2 -veined (62/69), or 3 -veined (6/69); obtuse (1/2), or acute (1/2). Fertile lemma linear (6), or lanceolate (58), or oblong (40); hyaline; without keel; wingless; 0 -veined (1/21), or 1 -veined (15/21), or 2 -veined (4/21), or 3 -veined (8/21). Lemma surface unwrinkled; without grooves. Lemma margins eciliate (88), or ciliolate (5), or ciliate (10). Lemma apex entire (11), or dentate (13), or lobed (80); 2 -fid (93/93); incised 0.15–0.4038–0.66 of lemma length; acute (1/3), or acuminate (2/3); muticous (13), or mucronate (2), or awned (93); 1 -awned (93/93). Principal lemma awn apical (2/95), or from a sinus (93/95); straight (8/95), or curved (1/95), or flexuous (2/95), or geniculate (87/95). Column of lemma awn glabrous (86/88), or puberulous (2/88). Palea present (86), or absent or minute (18); 0.1–0.5614–1 length of lemma; hyaline (19/86), or membranous (67/86); 0 -veined (22/23), or 1 -veined (1/23), or 2 -veined (2/23); without keels (17/86), or 2-keeled (69/86). Palea keels smooth (68/69), or scabrous (1/69); eciliate (68/69), or ciliolate (1/69). Palea apex entire (1/2), or erose (2/2).

FLOWER Lodicules 2 (12/12); fleshy (3/3); glabrous (11/12), or ciliate (1/12); truncate (3/3). Anthers 1 (8/63), or 2 (1/63), or 3 (56/63).

FRUIT Caryopsis with adherent pericarp (3/3); linear (1/2), or oblong (1/2), or ovoid (1/2).

DISTRIBUTION Europe (2), or Africa (49), or Temperate Asia (8), or Tropical Asia (11), or Australasia (3), or Pacific (3), or North America (19), or South America (42).

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