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Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Tripogon

HABIT Annual (3), or perennial (42). Rhizomes absent (42), or short (2). Culms erect (38/39), or geniculately ascending (2/39); slender (3/3); 3–30.9–90 cm long; firm (42), or wiry (2); without nodal roots (1/1), or rooting from lower nodes (1/1). Lateral branches lacking (8/8). Ligule an eciliate membrane (8), or a ciliolate membrane (20), or a ciliate membrane (6), or a fringe of hairs (10), or absent (1). Leaf-blades persistent (43), or deciduous at the ligule (1); aciculate (1), or filiform (26), or linear (18), or lanceolate (1); herbaceous (43), or coriaceous (1); stiff (7), or firm (37). Leaf-blade midrib indistinct (2/3), or conspicuous (1/3). Leaf-blade apex muticous (43), or pungent (1).

INFLORESCENCE Inflorescence composed of racemes; exserted, or embraced at base by subtending leaf (1).

Racemes single; erect (9), or ascending (33), or drooping (3); linear, or oblong (1); unilateral; bearing 7–9 fertile spikelets on each (1/5), or 10–14 fertile spikelets on each (2/5), or 15–24 fertile spikelets on each (3/5), or 25 fertile spikelets on each (4/5), or 26–35 fertile spikelets on each (3/5), or 36–48 fertile spikelets on each (2/5), or 49–60 fertile spikelets on each (1/5). Rhachis flattened (16/36), or angular (19/36), or subcylindrical and excavated (1/36). Spikelet packing broadside to rhachis; crowded (4), or contiguous (33), or lax (5), or distant (3); 2 -rowed (38/38).

Spikelets sunken (1/31), or appressed (27/31), or ascending (3/31); solitary. Fertile spikelets sessile (43), or pedicelled (2). Pedicels reduced to a stump (3/3).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets (2/2); 2–9–50 fertile florets; with a barren rhachilla extension (2), or with diminished florets at the apex (42). Spikelets linear (4), or lanceolate (3), or elliptic (6), or oblong (34), or cuneate (1); laterally compressed; 2.5–10.94–65 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; glabrous (41), or pilose (1), or villous (2). Floret callus pubescent (16/37), or pilose (12/37), or bearded (9/37).

GLUMES Glumes persistent; shorter than spikelet; thinner than fertile lemma (2), or similar to fertile lemma in texture (40), or firmer than fertile lemma (2); parallel to lemmas (43), or recurved at apex (1), or gaping (1). Lower glume linear (7), or lanceolate (36), or oblong (5), or ovate (3); 0.25–0.6498–1 length of upper glume; membranous (43), or coriaceous (1); 1-keeled; 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth (43), or asperulous (1); without pits. Lower glume apex entire (31), or with a unilateral tooth (9), or dentate (4); 2 -fid (4/4); emarginate (1/40), or truncate (1/40), or obtuse (6/40), or acute (18/40), or acuminate (23/40), or attenuate (1/40), or setaceously attenuate (1/40); muticous (39), or mucronate (5), or awned (3). Upper glume linear (2), or lanceolate (32), or elliptic (5), or oblong (12); 0.75–1.2–2 length of adjacent fertile lemma; membranous (41), or coriaceous (3); with undifferentiated margins (41), or membranous margins (1), or scarious margins (2); 1-keeled; 1 -veined (38/42), or 2 -veined (2/42), or 3 -veined (6/42). Upper glume apex entire (38), or dentate (7); 2 -fid (7/7); emarginate (7/38), or truncate (2/38), or obtuse (5/38), or acute (15/38), or acuminate (17/38), or setaceously attenuate (1/38), or caudate (1/38); muticous (28), or mucronate (13), or awned (7); 1 -awned (7/7).

FLORETS Basal sterile florets barren (2/2); without significant palea (2/2). Lemma of lower sterile floret elliptic (1/2), or ovate (1/2); membranous (2/2); 1 -veined (2/2); acute (2/2); mucronate (1/2), or awned (1/2). Fertile lemma linear (1), or lanceolate (13), or elliptic (13), or oblong (19), or ovate (9); membranous (38), or chartaceous (1), or cartilaginous (1), or coriaceous (4); of similar consistency on margins (43), or much thinner on margins (1); without keel (42), or keeled (2); wingless; 3 -veined. Lemma midvein without distinctive roughness, or scaberulous (1). Lemma lateral veins prominent (2/2); excurrent (11/22), or extending close to apex (12/22). Lemma surface smooth (42), or asperulous (1), or scaberulous (1); unwrinkled; without grooves. Lemma apex entire (5), or dentate (33), or lobed (8); 2 -fid (34/41), or 3 -fid (3/41), or 4 -fid (4/41), or 6 -fid (2/41); incised 0.33 of lemma length; emarginate (3/15), or truncate (3/15), or obtuse (8/15), or acute (3/15), or acuminate (3/15); mucronate (6), or awned (41); 1 -awned (25/41), or 3 -awned (17/41). Principal lemma awn apical (5), or from a sinus (40); straight (39), or curved (1), or flexuous (5), or geniculate (1). Lateral lemma awns subequal to principal (3/8), or shorter than principal (5/8). Palea embraced by lemma (43), or reflexed at apex (1), or separating from lemma above (1); 0.33–0.9272–1 length of lemma; 2 -veined (43/43). Palea keels wingless (22), or winged (22); smooth (38), or scaberulous (5), or scabrous (2); eciliate (16), or ciliolate (26), or ciliate (2). Palea surface glabrous (42), or pilose (2). Palea apex dentate (3/3); muticous (43), or with excurrent keel veins (1). Apical sterile florets resembling fertile though underdeveloped (42/42).

FLOWER Lodicules 2 (8/8); irregularly toothed (1/1); truncate (1/1). Anthers 1 (2/39), or 2 (6/39), or 3 (31/39). Stigmas 2 (1/1).

FRUIT Caryopsis with adherent pericarp (43/43); linear (1/13), or lanceolate (4/13), or ellipsoid (4/13), or oblong (5/13), or ovoid (2/13), or obovoid (1/13); isodiametric (7/7); biconvex (2/8), or plano-convex (1/8), or trigonous (5/8). Embryo 0.25–0.3883–0.5 length of caryopsis. Hilum punctiform (1/2), or elliptic (1/2).

DISTRIBUTION Africa (9), or Temperate Asia (18), or Tropical Asia (25), or Australasia (1), or North America (1), or South America (3).

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