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.

Ischaemum

HABIT Annual (29), or perennial (53). Rhizomes absent (76), or short (4), or elongated (2). Stolons absent (77), or present (5). Culms erect (28/68), or geniculately ascending (19/68), or decumbent (27/68), or prostrate (9/68), or rambling (9/68); robust (2/8), or slender (4/8), or weak (2/8); 5–63.99–300 cm long; firm (78), or wiry (3), or woody (1); without nodal roots (2/28), or with prop roots (2/28), or rooting from lower nodes (26/28). Culm-internodes terete (2/4), or channelled (2/4), or elliptical in section (1/4). Culm-nodes constricted (1/2), or swollen (1/2). Lateral branches lacking (10/27), or sparse (7/27), or ample (14/27). Leaf-sheath auricles absent (73), or erect (9). Ligule an eciliate membrane (70), or a ciliolate membrane (12), or a fringe of hairs (1). Leaf-blade base without a false petiole (64), or with a brief petiole-like connection to sheath (5), or with a false petiole (18). Leaf-blades linear (48), or lanceolate (46), or elliptic (4), or oblong (3), or ovate (2); herbaceous (81), or coriaceous (1); stiff (1), or firm (79), or flaccid (2). Leaf-blade midrib conspicuous (1/1). Leaf-blade margins cartilaginous (1/1).

INFLORESCENCE Inflorescence composed of racemes; terminal (77), or terminal and axillary (5); subtended by an unspecialized leaf-sheath (73), or an inflated leaf-sheath (2), or a spatheole (7); exserted (80), or embraced at base by subtending leaf (2), or enclosed (3). Spatheole lanceolate (5/5).

Racemes single (8), or paired (73), or digitate (10); side by side (31/77), or appressed back to back (46/77); unilateral (3/3); bearing 8–9 fertile spikelets on each (1/2), or 10–12 fertile spikelets on each (2/2), or 13–14 fertile spikelets on each (1/2). Rhachis fragile at the nodes; angular (70/78), or subterete (4/78), or semiterete (4/78). Rhachis internodes linear (5), or columnar (10), or oblong (35), or clavate (15), or cuneate (9), or pyriform (1), or inflated (7); unspecialized (23), or flat and forming a U or V shape with the pedicel in rear view (58), or with a basal circular pore between internode and pedicel (4), or with the lower often bearing triads (2). Rhachis internode tip transverse (81), or oblique (1); cupuliform (81), or notched (1).

Spikelets in pairs. Fertile spikelets sessile (80), or sessile and pedicelled (3); 1 in the cluster (80), or 2 in the cluster (3). Companion sterile spikelets pedicelled (80/80); 0 in the cluster (1/80), or 1 in the cluster (80/80). Pedicels linear (5/81), or columnar (10/81), or oblong (48/81), or narrowly elliptic (1/81), or clavate (8/81), or cuneate (7/81), or pyriform (1/81), or inflated (1/81).

STERILE SPIKELETS Basal sterile spikelets absent (80), or well-developed (2).

Companion sterile spikelets absent (2), or represented by single glumes (2), or rudimentary (6), or well-developed (78); persistent (2/78), or separately deciduous (78/78). Companion sterile spikelet callus indistinct (79/80), or oblong (1/80). Companion sterile spikelet glumes muticous (38/49), or mucronate (1/49), or awned (10/49).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets (81), or 7–14 basal sterile florets (1); 1 fertile florets; without rhachilla extension. Spikelets linear (1), or lanceolate (20), or elliptic (21), or oblong (40), or ovate (13), or obovate (2), or rhomboid (1); laterally compressed (1), or dorsally compressed (81); 2.5–6.061–12 mm long; falling entire; deciduous from the base (2), or with accessory branch structures. Spikelet callus brief (40), or square (11), or oblong (28), or cuneate (3); glabrous (9/60), or pubescent (19/60), or pilose (21/60), or bearded (14/60); base truncate (65), or obtuse (17); inserted.

GLUMES Glumes reaching apex of florets (2), or exceeding apex of florets (80); firmer than fertile lemma. Lower glume subulate (1), or lanceolate (11), or elliptic (14), or oblong (48), or ovate (20), or obovate (1); membranous (1), or chartaceous (13), or cartilaginous (1), or coriaceous (67), or indurate (1); without keels (1), or 2-keeled (81); wingless (45), or winged on keel (39); 1–9–21 -veined. Lower glume lateral veins obscure (6), or distinct (76); intercarinal veins distinct (1/1). Lower glume surface convex (49), or flat (33), or concave (3); smooth (47), or asperulous (6), or scabrous (3), or muricate (11), or rugose (21); not waisted (79), or laterally waisted (3); without pits; glabrous (61), or puberulous (1), or pubescent (6), or pilose (16), or hirsute (3), or villous (9), or woolly (1); without hair tufts (80), or with marginal tufts of hair (1), or with transverse tufts of hair (1). Lower glume apex entire (50), or erose (1), or dentate (32); 2 -fid (29/32), or 3 -fid (3/32); emarginate (5/34), or truncate (1/34), or obtuse (8/34), or acute (20/34), or acuminate (3/34), or attenuate (1/34); muticous (76), or mucronate (1), or awned (6). Upper glume lanceolate (64), or elliptic (6), or oblong (4), or ovate (14); membranous (1), or chartaceous (21), or cartilaginous (1), or coriaceous (60); with undifferentiated margins (80), or hyaline margins (1), or membranous margins (1); without keels (1), or 1-keeled (81); wingless (59), or winged on keel (23); 1 -veined (1/50), or 3 -veined (26/50), or 4 -veined (9/50), or 5 -veined (25/50), or 6 -veined (2/50), or 7 -veined (7/50), or 8–9 -veined (2/50). Upper glume primary vein eciliate (74), or ciliolate (2), or ciliate (6). Upper glume lateral veins with cross-veins (1/1). Upper glume surface smooth (70), or asperulous (4), or scabrous (6), or tuberculate (1), or rugose (1); glabrous (70), or puberulous (2), or pubescent (3), or pilose (4), or hirsute (1), or villous (2); without hair tufts (79), or with marginal tufts of hair (1), or with a dorsal tuft of hair (2). Upper glume apex entire (77), or dentate (4), or lobed (1); 2 -fid (5/5); emarginate (2/36), or obtuse (4/36), or acute (8/36), or acuminate (22/36), or attenuate (2/36), or setaceously attenuate (1/36); muticous (60), or mucronate (5), or awned (19); 1 -awned (17/18), or 2 -awned (1/18).

FLORETS Basal sterile florets male (80), or barren (2); with palea (81), or without significant palea (1). Lemma of lower sterile floret lanceolate (59), or elliptic (9), or oblong (16), or ovate (12); hyaline (28), or membranous (54); 1–2 -veined (4/51), or 3 -veined (44/51), or 4 -veined (11/51), or 5 -veined (12/51), or 7 -veined (2/51); truncate (2/26), or obtuse (1/26), or acute (14/26), or acuminate (10/26). Palea of lower sterile floret wingless (80/81), or winged on keels (1/81). Fertile lemma linear (1), or lanceolate (8), or elliptic (4), or oblong (66), or ovate (3); hyaline (22), or membranous (60); without keel; wingless (81), or winged on margins (1); 1 -veined (2/39), or 3 -veined (34/39), or 4 -veined (3/39), or 5 -veined (6/39). Lemma lateral veins obscure (4/4). Lemma surface unwrinkled; without grooves. Lemma margins eciliate (62), or ciliolate (9), or ciliate (11). Lemma apex entire (3), or dentate (14), or lobed (68); 2 -fid (81/81); incised 0.1–0.4755–0.75 of lemma length; muticous (8), or mucronate (3), or awned (77), or awned only on distal spikelets (1); 1 -awned (78/78). Principal lemma awn apical (3/80), or from a sinus (78/80); straight (6/80), or curved (3/80), or flexuous (1/80), or geniculate (72/80). Palea present (81), or absent or minute (1); 0.33–0.9855–1.25 length of lemma; hyaline (5/81), or membranous (76/81); 0 -veined (1/4), or 2 -veined (3/4); without keels (1/81), or 2-keeled (80/81). Palea keels smooth (79/80), or scaberulous (1/80).

FLOWER Lodicules 2 (14/14); free (13/14), or adnate to palea (1/14). Anthers 3 (71/71). Stigmas 2 (1/1).

FRUIT Caryopsis with adherent pericarp (6/6); ellipsoid (2/6), or oblong (4/6), or obovoid (1/6); dorsally compressed (2/2). Embryo 0.5 length of caryopsis. Hilum punctiform (1/1).

DISTRIBUTION Africa (13), or Temperate Asia (14), or Tropical Asia (66), or Australasia (9), or Pacific (10), or North America (2), or South America (7).

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