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.

Triodia

HABIT Perennial. Rhizomes absent, or elongated (1). Stolons absent (62), or present (7). Culms erect (17/19), or geniculately ascending (3/19), or decumbent (1/19), or rambling (1/19); robust (1/2), or slender (1/2); 20–97.29–300 cm long; without nodal roots (1/4), or with prop roots (2/4), or rooting from lower nodes (2/4). Culm-internodes terete (6/6), or elliptical in section (1/6). Lateral branches lacking (7/14), or ample (5/14), or fastigiate (2/14). Leaf-sheath auricles absent (65), or erect (3). Ligule a ciliate membrane (1), or a fringe of hairs (67). Leaf-blade base without a false petiole (60), or with a brief petiole-like connection to sheath (5), or with a false petiole (3). Leaf-blades persistent (67), or deciduous at the ligule (1); aciculate (39), or filiform (14), or linear (16); herbaceous (44), or coriaceous (24); stiff (60), or firm (9); without exudate (48), or resinous (21); without scent (63), or aromatic (5). Leaf-blade margins unthickened (1/2), or cartilaginous (1/2). Leaf-blade apex muticous (19), or pungent (49).

INFLORESCENCE Inflorescence a panicle (55), or composed of racemes (13); exserted, or embraced at base by subtending leaf (3).

Panicle open (47/55), or contracted (7/55), or spiciform (1/55).

Racemes single (4/13), or borne along a central axis (9/13); appressed (6/13), or ascending (7/13); unilateral (11/12), or bilateral (1/12); bearing 14–18 fertile spikelets on each (1/1). Rhachis angular (1/1). Spikelet packing broadside to rhachis (4/4); 2 -rowed (5/5).

Spikelets appressed (1/1); solitary, or in pairs (3). Fertile spikelets sessile (4), or sessile and pedicelled (1), or pedicelled (64). Pedicels filiform (10/12), or linear (1/12), or oblong (1/12).

FERTILE SPIKELETS Spikelets comprising 1–6–21 fertile florets; with diminished florets at the apex. Spikelets linear (11), or lanceolate (23), or elliptic (17), or oblong (19), or ovate (7), or cuneate (10); laterally compressed (64), or subterete (8), or dorsally compressed (1); 3–10.71–27 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes brief up to lowest fertile floret (60), or elongated between glumes (8); suppressed between florets (1/66), or definite (65/66); glabrous (61/65), or pubescent (4/65). Floret callus brief (62), or evident (3), or elongated (3); glabrous (13/46), or sparsely hairy (1/46), or pubescent (16/46), or pilose (9/46), or bearded (8/46), or woolly (1/46); truncate (6), or obtuse (56), or acute (5), or pungent (3).

GLUMES Glumes persistent; shorter than spikelet (57), or reaching apex of florets (10), or exceeding apex of florets (5); thinner than fertile lemma (51), or similar to fertile lemma in texture (17); parallel to lemmas (66), or gaping (2). Lower glume linear (8), or lanceolate (43), or elliptic (8), or oblong (24), or ovate (9); clasping (1/1); 0.33–0.991–1.3 length of upper glume; membranous (10), or chartaceous (4), or scarious (44), or cartilaginous (14), or coriaceous (7); without keels (48), or 1-keeled (22); 1–4–16 -veined. Lower glume lateral veins absent (14), or obscure (10), or distinct (49), or prominent (2). Lower glume surface convex, or flat (1); smooth (44), or asperulous (27), or scabrous (7); without pits; glabrous (67), or pubescent (1), or pilose (2). Lower glume apex entire (65), or dentate (6), or lobed (2); 2 -fid (7/8), or 3 -fid (1/8); emarginate (2/66), or truncate (2/66), or obtuse (20/66), or acute (35/66), or acuminate (27/66), or attenuate (1/66), or setaceously attenuate (4/66); muticous (48), or mucronate (20), or awned (8). Upper glume linear (8), or lanceolate (42), or elliptic (8), or oblong (24), or ovate (9), or orbicular (1), or oblate (1); 0.4–1.418–5 length of adjacent fertile lemma; hyaline (1), or membranous (10), or chartaceous (5), or scarious (45), or cartilaginous (11), or coriaceous (7); with undifferentiated margins (63), or hyaline margins (1), or membranous margins (3), or scarious margins (1); without keels (48), or 1-keeled (22); 1–4–16 -veined. Upper glume surface smooth (47), or asperulous (26), or scabrous (5); glabrous (67), or pubescent (1), or pilose (2). Upper glume apex entire (62), or with a unilateral tooth (1), or dentate (8), or lobed (3); 1 -fid (1/11), or 2 -fid (8/11), or 3 -fid (3/11); emarginate (4/63), or truncate (2/63), or obtuse (19/63), or acute (38/63), or acuminate (22/63), or attenuate (1/63), or setaceously attenuate (4/63); muticous (47), or mucronate (21), or awned (8); 1 -awned (7/8), or 3 -awned (1/8).

FLORETS Fertile lemma lanceolate (15), or elliptic (2), or oblong (43), or ovate (15), or orbicular (1), or obovate (3); membranous (7), or chartaceous (2), or scarious (9), or cartilaginous (10), or coriaceous (43), or indurate (7); of similar consistency above (64), or much thinner above (3), or firmer above (1); of similar consistency on margins (55), or much thinner on margins (13); without keel (66), or keeled (3); wingless; 3–7–15 -veined. Lemma midvein eciliate (42), or ciliolate (6), or ciliate (13), or pubescent (8). Lemma lateral veins obscure (2/6), or with distinct primaries but obscure intermediates (4/6). Lemma surface smooth (55), or scaberulous (14), or scabrous (1); unwrinkled; without grooves; glabrous (28), or puberulous (2), or pubescent (27), or pilose (9), or hirsute (5), or villous (1), or woolly (1); hairy on back (42/45), or between veins (1/45), or in lines (2/45). Lemma margins eciliate (37), or ciliolate (7), or ciliate (17), or pubescent (12). Lemma apex entire (5), or erose (1), or dentate (20), or lobed (43); 2 -fid (11/63), or 3 -fid (52/63); incised 0.05–0.2898–0.75 of lemma length; emarginate (2/34), or obtuse (5/34), or acute (21/34), or acuminate (11/34); muticous (39), or mucronate (9), or awned (24); 1 -awned (4/24), or 3 -awned (21/24). Principal lemma awn apical (26/33), or from a sinus (7/33); straight (27/33), or curved (7/33); limb glabrous (32/33), or ciliate (1/33). Lateral lemma awns subequal to principal (1/21), or shorter than principal (20/21). Palea embraced by lemma (67), or reflexed at apex (2); 0.5–0.8646–1 length of lemma; hyaline (2), or membranous (47), or scarious (4), or cartilaginous (13), or coriaceous (6), or indurate (4); 2 -veined (16/17), or 3 -veined (1/17). Palea keels unthickened (60), or thickened (8); wingless (41), or winged (27); smooth (46), or scaberulous (17), or scabrous (5); eciliate (44), or ciliolate (18), or ciliate (6). Palea surface glabrous (49), or puberulous (2), or pubescent (17), or pilose (2), or hirsute (1), or villous (1), or woolly (1). Palea apex entire (4/14), or erose (1/14), or dentate (11/14); muticous (67), or with excurrent keel veins (1). Apical sterile florets resembling fertile though underdeveloped (64), or distinct from fertile (4); 1–2 in number (1/5), or 3 in number (2/5), or 4 in number (1/5), or 5–6 in number (2/5), or 7 in number (1/5); barren (2/2); separate (2/4), or in a clump (2/4); rudimentary (2/4), or lanceolate (1/4), or orbicular (1/4). Apical sterile lemmas muticous (2/4), or awned (2/4).

FLOWER Lodicules 2 (37/37); fleshy (36/36); emarginate (1/2), or truncate (1/2). Anthers 3 (65/65).

FRUIT Caryopsis with adherent pericarp (35/35); fusiform (1/4), or ellipsoid (2/4), or obovoid (3/4). Embryo 0.33 length of caryopsis. Hilum elliptic (1/1).

DISTRIBUTION Australasia.

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