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.

Sorghum

HABIT Annual (20), or perennial (13). Rhizomes absent (25), or short (3), or elongated (4). Culms erect (20/20), or geniculately ascending (4/20), or decumbent (1/20); robust (5/5), or of moderate stature (1/5); 25–180.2–600 cm long; firm (30), or wiry (1); without nodal roots (14/15), or with prop roots (11/15). Culm-nodes constricted (3/3), or flush with internodes (2/3). Lateral branches lacking (6/8), or sparse (6/8). Leaf-sheath auricles absent (30), or erect (1). Ligule an eciliate membrane (16), or a ciliolate membrane (18), or a ciliate membrane (1). Leaf-blades linear, or lanceolate (1); stiff (1), or firm (30). Leaf-blade midrib widened (1/1).

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme; terminal, or terminal and axillary (1).

Panicle open (28), or contracted (4). Primary panicle branches not whorled (19), or whorled at lower nodes (2), or whorled at most nodes (10); without sterile bristles (30), or sterile at lowest node (1).

Racemes bearing a triad of spikelets (7), or few fertile spikelets (20), or many spikelets (7); 1–4–21 fertile spikelets on each. Rhachis evident (28), or obsolete (6); tough (6), or fragile at the nodes (26). Rhachis internodes filiform (14/28), or linear (15/28). Rhachis internode tip transverse (19/28), or oblique (9/28); cupuliform (14/14).

Spikelets appressed (5/5); in pairs (28), or in threes (7). Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster (26), or 2 in the cluster (8). Pedicels filiform (30), or linear (1).

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

Companion sterile spikelets represented by barren pedicels (1), or well-developed (30); persistent (5/30), or separately deciduous (26/30). Companion sterile spikelet callus indistinct (29/30), or square (1/30). Companion sterile spikelet glumes muticous (29/30), or mucronate (2/30), or awned (2/30).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (1), or lanceolate (8), or elliptic (15), or oblong (6), or ovate (5), or orbicular (1), or obovate (5), or oblanceolate (2); dorsally compressed; 3–8.161–20 mm long; persistent on plant (2), or falling entire (29); deciduous with accessory branch structures (29/29). Spikelet callus brief (19), or square (2), or oblong (1), or cuneate (8), or linear (2); glabrous (1/18), or pubescent (5/18), or pilose (7/18), or bearded (6/18); base truncate (1), or obtuse (21), or pungent (10); attached obliquely (2/2).

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma; parallel to lemmas, or gaping (1). Lower glume lanceolate (1), or elliptic (4), or oblong (1), or ovate (25); chartaceous (3), or cartilaginous (3), or coriaceous (27); without keels (23), or 2-keeled (8); wingless (29), or winged on keel (2); 5–9–20 -veined. Lower glume lateral veins without ribs (30), or ribbed (1). Lower glume surface convex (30), or flat (1); smooth (29), or asperulous (1), or scabrous (1); without pits; glabrous (17), or puberulous (5), or pubescent (13), or pilose (12), or villous (5), or hispid (1). Lower glume apex entire (22), or dentate (10); 2 -fid (4/10), or 3 -fid (6/10); emarginate (1/20), or truncate (1/20), or obtuse (3/20), or acute (14/20), or rostrate (3/20); muticous (30), or mucronate (2). Upper glume lanceolate (1), or elliptic (2), or ovate (28); chartaceous (3), or cartilaginous (3), or coriaceous (27); without keels (29), or 1-keeled (2); wingless (30), or winged on margins (1); 5 -veined (8/20), or 6 -veined (7/20), or 7 -veined (19/20), or 8–9 -veined (3/20), or 10–11 -veined (1/20). Upper glume lateral veins without cross-veins (1/4), or with cross-veins (4/4). Upper glume surface smooth (29), or asperulous (1), or scabrous (1); glabrous (20), or puberulous (3), or pubescent (14), or pilose (9), or villous (2); with simple hairs (21/22), or tubercle-based hairs (2/22). Upper glume apex entire (30), or dentate (2); 2 -fid (2/2); truncate (1/11), or obtuse (3/11), or acute (6/11), or acuminate (2/11), or setaceously attenuate (2/11); muticous, or mucronate (1).

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate (17), or elliptic (13), or oblong (1); hyaline; 2 -veined (30/30), or 3–5 -veined (1/30); acute (19/19). Fertile lemma lanceolate (1), or elliptic (2), or oblong (19), or ovate (8), or obovate (1); dorsally compressed (2/2); hyaline; wingless; 1 -veined (30), or 2 -veined (1), or 3 -veined (2). Lemma surface unwrinkled; without grooves; glabrous (30), or pubescent (1). Lemma margins eciliate (13), or ciliolate (3), or ciliate (15). Lemma apex entire (3), or dentate (21), or lobed (10); 2 -fid; incised 0.2–0.2817–0.33 of lemma length; muticous (7), or awned (30); 1 -awned (30/30). Principal lemma awn from a sinus (30/30); geniculate (30/30). Column of lemma awn glabrous (17/30), or pubescent (11/30), or ciliate (3/30). Palea present (4), or absent or minute (27); hyaline (1/4), or membranous (3/4); 0 -veined (1/1).

FLOWER Lodicules 2 (29/29); fleshy (19/19); glabrous (7/29), or ciliate (26/29). Anthers 3 (26/26). Stigmas 2 (19/19). Ovary glabrous (6/8), or pubescent on apex (2/8).

FRUIT Caryopsis with adherent pericarp (25/25); ellipsoid (7/17), or oblong (4/17), or ovoid (1/17), or obovoid (12/17); isodiametric (1/7), or dorsally compressed (5/7), or flattened (1/7); apex umbonate (1/1). Embryo 0.5–0.55–0.6 length of caryopsis. Hilum punctiform (3/3).

DISTRIBUTION Europe (3), or Africa (8), or Temperate Asia (8), or Tropical Asia (14), or Australasia (23), or Pacific (6), or North America (5), or South America (6).

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