Ischaemum L.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Perennial, sometimes annual; ligule membranous

Morphology Reproductive morphology Inflorescences

Inflorescence of paired or occasionally digitate racemes, the former often interlocked back to back, terminal or axillary; internodes and pedicels clavate to inflated, the pedicels often very short

Morphology Reproductive morphology Inflorescences Spikelets

Sessile spikelet dorsally compressed; callus obtuse and inserted into the concave top of the internode; lower glume chartaceous to coriaceous, concave to convex, laterally 2-keeled or the flanks rounded, often rugose, sometimes winged; lower floret male and with a palea; upper lemma bifid, awned from between the teeth or awnless; caryopsis oblong to lanceolate, dorsally compressed Pedicelled spikelet as large as the sessile or much smaller, often asymmetrical.

Distribution

Some 85 species throughout the tropics, but mostly in Asia.

Gramineae, T. A. Cope. Flora Zambesiaca 10:4. 2002

Morphology General Habit

Perennials, sometimes annuals, often decumbent.

Morphology Leaves Leaf sheaths

Leaf sheaths mostly with auricles; ligule membranous; leaf laminas linear, sometimes sagittate or falsely petiolate at the base.

Morphology Reproductive morphology Inflorescences

Inflorescence of paired, sometimes solitary or digitate, 1-sided racemes, those of a pair often interlocked back to back and mimicking a solitary raceme, terminal or axillary; rhachis internodes and pedicels stoutly linear to clavate or inflated, often exposed on the back of the raceme as a U- or V-shaped segment, sometimes the pedicels so short that the spikelets of a pair appear to be side by side.

Morphology Reproductive morphology Inflorescences Spikelets

Sessile spikelet dorsally compressed; callus obtuse and inserted in the concave top of the internode; inferior glume chartaceous to coriaceous, convex to concave on the back, laterally 2-keeled, often rugose, sometimes winged; superior glume awned or awnless; inferior floret male, rarely barren, with a palea; superior lemma bifid, passing between the teeth into a glabrous awn (rarely awnless). Pedicelled spikelet as large as the sessile spikelet or much smaller, often asymmetrical.

Morphology Reproductive morphology Fruits

Caryopsis oblong to lanceolate, dorsally compressed.

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Morphology General Habit

Annual (28), or perennial (52). Rhizomes absent (74), or short (4), or elongated (2). Stolons absent (75), or present (5). Culms erect (27/66), or geniculately ascending (19/66), or decumbent (26/66), or prostrate (9/66), or rambling (9/66); robust (2/8), or slender (4/8), or weak (2/8); 5-63.92-300 cm long; firm (76), or wiry (3), or woody (1); without nodal roots (2/27), or with prop roots (2/27), or rooting from lower nodes (25/27). Culm-internodes terete (2/3), or channelled (2/3). 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 (72), or erect (8). Ligule an eciliate membrane (68), or a ciliolate membrane (12), or a fringe of hairs (1). Leaf-blade base without a false petiole (63), or with a brief petiole-like connection to sheath (5), or with a false petiole (17). Leaf-blades linear (47), or lanceolate (44), or elliptic (4), or oblong (3), or ovate (2); herbaceous (79), or coriaceous (1); stiff (1), or firm (77), or flaccid (2). Leaf-blade margins cartilaginous (1/1).

Morphology Reproductive morphology Inflorescences

Inflorescence composed of racemes; terminal (76), or terminal and axillary (4); subtended by an unspecialized leaf-sheath (71), or an inflated leaf-sheath (2), or a spatheole (7); exserted (78), or embraced at base by subtending leaf (2), or enclosed (3). Spatheole lanceolate (5/5). Racemes single (8), or paired (71), or digitate (10); side by side (31/75), or appressed back to back (44/75); unilateral (2/2); 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 (68/76), or subterete (4/76), or semiterete (4/76). Rhachis internodes linear (5), or columnar (9), or oblong (35), or clavate (15), or cuneate (8), or pyriform (1), or inflated (7); unspecialized (23), or flat and forming a U or V shape with the pedicel in rear view (56), or with a basal circular pore between internode and pedicel (4), or with the lower often bearing triads (2). Rhachis internode tip transverse (79), or oblique (1); cupuliform (79), or notched (1). Spikelets in pairs. Fertile spikelets sessile (78), or sessile and pedicelled (3); 1 in the cluster (78), or 2 in the cluster (3). Companion sterile spikelets pedicelled (78/78); 0 in the cluster (1/78), or 1 in the cluster (78/78). Pedicels linear (5/79), or columnar (9/79), or oblong (48/79), or narrowly elliptic (1/79), or clavate (8/79), or cuneate (6/79), or pyriform (1/79), or inflated (1/79).

Sterile

Basal sterile spikelets absent (78), or well-developed (2). Companion sterile spikelets absent (2), or represented by single glumes (2), or rudimentary (6), or well-developed (76); persistent (2/76), or separately deciduous (76/76). Companion sterile spikelet callus indistinct (77/78), or oblong (1/78). Companion sterile spikelet glumes muticous (36/47), or mucronate (1/47), or awned (10/47).

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (1), or lanceolate (19), or elliptic (21), or oblong (39), or ovate (13), or obovate (2), or rhomboid (1); laterally compressed (1), or dorsally compressed (79); 2.5-6.055-12 mm long; falling entire; deciduous from the base (2), or with accessory branch structures. Spikelet callus brief (39), or square (11), or oblong (27), or cuneate (3); glabrous (9/58), or pubescent (18/58), or pilose (21/58), or bearded (13/58); base truncate (65), or obtuse (15); inserted. Basal sterile spikelets absent (78), or well-developed (2). Companion sterile spikelets absent (2), or represented by single glumes (2), or rudimentary (6), or well-developed (76); persistent (2/76), or separately deciduous (76/76). Companion sterile spikelet callus indistinct (77/78), or oblong (1/78). Companion sterile spikelet glumes muticous (36/47), or mucronate (1/47), or awned (10/47).

Fertile

Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets linear (1), or lanceolate (19), or elliptic (21), or oblong (39), or ovate (13), or obovate (2), or rhomboid (1); laterally compressed (1), or dorsally compressed (79); 2.5-6.055-12 mm long; falling entire; deciduous from the base (2), or with accessory branch structures. Spikelet callus brief (39), or square (11), or oblong (27), or cuneate (3); glabrous (9/58), or pubescent (18/58), or pilose (21/58), or bearded (13/58); base truncate (65), or obtuse (15); inserted.

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes reaching apex of florets (2), or exceeding apex of florets (78); firmer than fertile lemma. Lower glume subulate (1), or lanceolate (11), or elliptic (14), or oblong (46), or ovate (20), or obovate (1); membranous (1), or chartaceous (12), or cartilaginous (1), or coriaceous (66), or indurate (1); without keels (1), or 2-keeled (79); wingless (44), or winged on keel (38); 1-9-21 -veined. Lower glume lateral veins obscure (6), or distinct (74); intercarinal veins distinct (1/1). Lower glume surface convex (48), or flat (33), or concave (2); smooth (46), or asperulous (6), or scabrous (3), or muricate (11), or rugose (20); not waisted (77), or laterally waisted (3); glabrous (60), or puberulous (1), or pubescent (6), or pilose (15), or hirsute (3), or villous (9), or woolly (1); without hair tufts (78), or with marginal tufts of hair (1), or with transverse tufts of hair (1). Lower glume apex entire (49), or erose (1), or dentate (31); 2 -fid (28/31), or 3 -fid (3/31); emarginate (5/34), or truncate (1/34), or obtuse (8/34), or acute (20/34), or acuminate (3/34), or attenuate (1/34); muticous (74), or mucronate (1), or awned (6). Upper glume lanceolate (62), or elliptic (6), or oblong (3), or ovate (14); membranous (1), or chartaceous (19), or cartilaginous (1), or coriaceous (60); with undifferentiated margins (78), or hyaline margins (1), or membranous margins (1); without keels (1), or 1-keeled (79); wingless (58), or winged on keel (22); 1 -veined (1/49), or 3 -veined (25/49), or 4 -veined (9/49), or 5 -veined (25/49), or 6 -veined (2/49), or 7 -veined (7/49), or 8-9 -veined (2/49). Upper glume primary vein eciliate (73), or ciliolate (1), or ciliate (6). Upper glume lateral veins with cross-veins (1/1). Upper glume surface smooth (68), or asperulous (4), or scabrous (6), or tuberculate (1), or rugose (1); glabrous (68), or puberulous (2), or pubescent (3), or pilose (4), or hirsute (1), or villous (2); without hair tufts (77), or with marginal tufts of hair (1), or with a dorsal tuft of hair (2). Upper glume apex entire (76), or dentate (3), or lobed (1); 2 -fid (4/4); emarginate (2/35), or obtuse (4/35), or acute (8/35), or acuminate (21/35), or attenuate (2/35), or setaceously attenuate (1/35); muticous (58), or mucronate (5), or awned (19); 1 -awned (17/18), or 2 -awned (1/18).

Morphology Reproductive morphology Flowers Florets

Basal sterile florets male (78), or barren (2); with palea (79), or without significant palea (1). Lemma of lower sterile floret lanceolate (57), or elliptic (9), or oblong (16), or ovate (11); hyaline (27), or membranous (53); 1-2 -veined (4/50), or 3 -veined (43/50), or 4 -veined (11/50), or 5 -veined (12/50), or 7 -veined (2/50); truncate (2/25), or obtuse (1/25), or acute (14/25), or acuminate (9/25). Palea of lower sterile floret wingless (78/79), or winged on keels (1/79). Fertile lemma linear (1), or lanceolate (8), or elliptic (4), or oblong (64), or ovate (3); hyaline (21), or membranous (59); without keel; wingless (79), 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 margins eciliate (60), or ciliolate (9), or ciliate (11). Lemma apex entire (3), or dentate (13), or lobed (67); 2 -fid (79/79); incised 0.1-0.471-0.75 of lemma length; muticous (8), or mucronate (3), or awned (75), or awned only on distal spikelets (1); 1 -awned (76/76). Principal lemma awn apical (3/78), or from a sinus (76/78); straight (6/78), or curved (3/78), or flexuous (1/78), or geniculate (70/78). Palea present (79), or absent or minute (1); 0.33-0.9752-1 length of lemma; hyaline (4/79), or membranous (75/79); 0 -veined (1/4), or 2 -veined (3/4); without keels (1/79), or 2-keeled (78/79). Palea keels smooth (77/78), or scaberulous (1/78).

Morphology Reproductive morphology Flowers

Lodicules 2 (14/14); free (13/14), or adnate to palea (1/14). Anthers 3 (70/70).

Morphology Reproductive morphology Fruits

Caryopsis with adherent pericarp (5/5); ellipsoid (2/5), or oblong (3/5), or obovoid (1/5); dorsally compressed (1/1).

Distribution

Africa (12), or Temperate Asia (14), or Tropical Asia (65), or Australasia (9), or Pacific (10), or North America (2), or South America (7).