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.

Pennisetum

HABIT Annual (12), or perennial (71). Rhizomes absent (55), or short (11), or elongated (17). Stolons absent (79), or present (3). Culms erect (42/63), or geniculately ascending (27/63), or decumbent (13/63), or prostrate (1/63), or rambling (2/63); reed-like (1/17), or robust (10/17), or slender (6/17); 3–130.9–800 cm long; compressible (1), or firm (70), or wiry (7), or woody (6); without nodal roots (3/10), or with prop roots (1/10), or rooting from lower nodes (9/10). Culm-internodes channelled (1/1). Culm-nodes constricted (1/2), or swollen (1/2). Lateral branches lacking (6/40), or sparse (2/40), or ample (26/40), or fastigiate (4/40), or suffrutescent (3/40). Leaf-sheath auricles absent (81), or erect (1). Ligule an eciliate membrane (3), or a ciliolate membrane (3), or a ciliate membrane (14), or a fringe of hairs (62). Leaf-blade base without a false petiole (79), or with a false petiole (5). Leaf-blades persistent (80), or deciduous at the ligule (2); aciculate (1), or filiform (3), or linear (72), or lanceolate (11); membranous (1), or herbaceous (79), or coriaceous (2); stiff (4), or firm (74), or flaccid (4). Leaf-blade midrib widened (1/1). Leaf-blade surface with rectangular ribs (1/1). Leaf-blade margins cartilaginous (2/2). Leaf-blade apex muticous (81), or pungent (1).

INFLORESCENCE Synflorescence simple (72), or compound (10); scanty (7/9), or paniculate (1/9), or fastigiate (1/9). Inflorescence a panicle (81), or comprising only a few spikelets (1); terminal (58), or terminal and axillary (24); subtended by an unspecialized leaf-sheath (78), or an inflated leaf-sheath (4); exserted (78), or embraced at base by subtending leaf (3), or enclosed (1).

Panicle spiciform (81/81). Panicle axis bearing persistent branches (10/81), or deciduous spikelet clusters (71/81).

Spikelets solitary (1), or subtended by an involucre. Fertile spikelets sessile (72/81), or sessile and pedicelled (5/81), or pedicelled (5/81); 1 in the cluster (79/81), or 2 in the cluster (18/81), or 3 in the cluster (10/81), or 4 in the cluster (5/81), or 5 in the cluster (3/81), or 6–9 in the cluster (1/81). Companion sterile spikelets sessile (1/5), or pedicelled (4/5); 0–1 in the cluster (1/5), or 2–3 in the cluster (4/5), or 4 in the cluster (3/5), or 5 in the cluster (1/5). Involucre composed of bristles; free throughout (81), or connate into a disc below (1). Involucral bristles persistent (1), or deciduous with the fertile spikelets (81); few (24), or numerous (58); 1–13–80 in principal whorl; terete (81), or flattened (1); flexible (80), or rigid (2).

STERILE SPIKELETS Companion sterile spikelets absent (77), or well-developed (5); deciduous with the fertile (4/4).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension, or with a barren rhachilla extension (3). Spikelets lanceolate (59), or elliptic (6), or oblong (12), or ovate (10), or obovate (2); subterete (1), or dorsally compressed (81); 2–5.375–20 mm long; persistent on plant (1), or falling entire (81); deciduous from the base (1/81), or with accessory branch structures (81/81). Spikelet callus pubescent (1/1); base truncate (7/7).

GLUMES Glumes both absent or obscure (5), or one the lower absent or obscure (23), or two (70); shorter than spikelet (75), or reaching apex of florets (11); thinner than fertile lemma. Lower glume lanceolate (9/70), or elliptic (4/70), or oblong (14/70), or ovate (35/70), or orbicular (7/70), or oblate (13/70); 0.5–0.775–1 length of upper glume; hyaline (33/68), or membranous (35/68); without keels (67/67); 0 -veined (46/68), or 1 -veined (36/68), or 2 -veined (5/68), or 3 -veined (6/68). Lower glume lateral veins absent (64/70), or obscure (2/70), or distinct (6/70). Lower glume surface smooth (69/70), or asperulous (1/70); without pits (70/70); glabrous (68/70), or puberulous (1/70), or pubescent (1/70). Lower glume apex entire (69/70), or erose (1/70); emarginate (5/67), or truncate (10/67), or obtuse (40/67), or acute (33/67), or acuminate (3/67); muticous (69/70), or mucronate (1/70). Upper glume lanceolate (12), or elliptic (8), or oblong (17), or ovate (48), or oblate (8); hyaline (19), or membranous (62), or herbaceous (1); without keels; 0–3–11 -veined. Upper glume surface smooth (80), or asperulous (3), or scabrous (1); glabrous (79), or puberulous (2), or pubescent (1). Upper glume apex entire, or dentate (1); 3 -fid (1/1); emarginate (7/81), or truncate (6/81), or obtuse (27/81), or acute (56/81), or acuminate (16/81), or caudate (1/81); muticous (80), or mucronate (5).

FLORETS Basal sterile florets male (47), or barren (68); with palea (49), or without significant palea (49). Lemma of lower sterile floret lanceolate (17), or elliptic (19), or oblong (27), or ovate (26), or oblate (1); hyaline (3), or membranous (63), or chartaceous (16); 0–5–15 -veined; emarginate (3/78), or truncate (1/78), or obtuse (12/78), or acute (42/78), or acuminate (29/78), or setaceously attenuate (3/78), or cuspidate (1/78), or caudate (1/78); muticous (75), or mucronate (8), or awned (1). Fertile lemma lanceolate (38), or elliptic (13), or oblong (9), or ovate (24); membranous (25), or chartaceous (28), or cartilaginous (9), or coriaceous (20); of similar consistency above (81), or much thinner above (1); of similar consistency on margins (80), or much thinner on margins (2); without keel; wingless; 3–4 -veined (4/56), or 5 -veined (55/56), or 6–7 -veined (13/56), or 8–9 -veined (3/56), or 10–12 -veined (1/56). Lemma surface smooth (69), or asperulous (2), or scaberulous (14); unwrinkled; without grooves; glabrous (81), or hispidulous (1). Lemma margins flat (81), or involute (1); eciliate (79), or ciliolate (1), or pubescent (2). Lemma apex emarginate (1/80), or truncate (1/80), or obtuse (12/80), or acute (46/80), or acuminate (26/80), or setaceously attenuate (1/80), or apiculate (3/80); muticous (76), or mucronate (7). Palea 0.5–0.9879–1.1 length of lemma; membranous (33), or chartaceous (21), or cartilaginous (8), or coriaceous (20); 2 -veined (3/3), or 3–4 -veined (1/3).

FLOWER Lodicules absent (61/64), or 2 (3/64); truncate (1/1). Anthers 3 (77/77). Stigmas 2 (2/2); plumose (81), or pubescent (1).

FRUIT Caryopsis with adherent pericarp (37/37); lanceolate (1/9), or ellipsoid (3/9), or oblong (5/9), or ovoid (2/9), or obovoid (1/9); isodiametric (1/6), or dorsally compressed (6/6). Embryo 0.5 length of caryopsis.

DISTRIBUTION Europe (3), or Africa (47), or Temperate Asia (23), or Tropical Asia (18), or Australasia (12), or Pacific (10), or North America (12), or South America (27), or Antarctica (1).

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