Trichoneura Andersson

Gramineae, W. D. Clayton, S. M. Phillips And S. A. Renvoize. Flora of Tropical East Africa. 1974

Morphology General Habit

Tufted annuals or perennials, with leafy often branching culms

Morphology Leaves

Leaf-blades linear, usually flat, pointed; ligule membranous, truncate

Morphology Reproductive morphology Inflorescences

Inflorescence open or contracted, composed of a number of racemes scattered along a central axis; racemes often stiff, the spikelets subsessile or shortly pedicelled, biseriate, overlapping or distant

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets wedge-shaped, several-flowered, with the florets loosely imbricate, disarticulating between the florets; glumes 1-nerved, very narrow and tapering to a mucro or awn, membranous, subequal, usually as long as the spikelet and always clearly exceeding the lower lemmas, persistent; lemmas 3-nerved, membranous, rounded or lightly keeled, often pilose, conspicuously ciliate along the lateral nerves, bluntly 2-toothed with a fine straight awn arising from the sinus; palea ± equalling the lemma, often capitate-pilose between the keels

Morphology Reproductive morphology Fruits

Caryopsis narrow, dorso-ventrally flattened, shallowly concavo-convex or plano-convex in cross-section.

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

Distribution

Seven species in tropical Africa and Arabia, Texas and the Galapagos Islands.

Morphology General Habit

Annual or perennial; ligule membranous

Morphology Reproductive morphology Inflorescences

Inflorescence composed of stiff spreading or short appressed racemes on a central axis

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets cuneate, several-flowered, disarticulating between the florets; glumes narrow, subequal, 1-nerved, longer than the adjacent lemmas and often as long as the spikelet, usually tapering to a mucro or awn; lemmas rounded or lightly keeled, membranous, ciliate on the lateral nerves, 2-toothed, mucronate or shortly awned; palea often capitate-pilose between the keels

Morphology Reproductive morphology Fruits

Caryopsis narrow, dorsally flattened, concavo-convex.

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Morphology General Habit

Annual (6), or perennial (2). Culms erect (2/7), or geniculately ascending (6/7), or decumbent (5/7); 3-41-110 cm long; rooting from lower nodes (1/1). Ligule an eciliate membrane. Leaf-blades persistent (7), or deciduous at the ligule (1); stiff (1), or firm (7).

Morphology Reproductive morphology Inflorescences

Inflorescence composed of racemes; not deciduous as a whole (7), or deciduous as a whole (1). Peduncle persistent (7), or fracturing (1). Racemes borne along a central axis; appressed (1), or ascending (6), or spreading (3); unilateral; bearing 8-9 fertile spikelets on each (1/1). Rhachis persistent (6), or deciduous from axis (2); angular. Spikelet packing broadside to rhachis; contiguous (7), or distant (1). Spikelets appressed (7/7); solitary. Fertile spikelets sessile (3), or pedicelled (5). Pedicels oblong (4/4).

Morphology Reproductive morphology Inflorescences Spikelets

Spikelets comprising 4 fertile florets (4), or 5-6 fertile florets, or 7-8 fertile florets (4), or 9 fertile florets (2); with diminished florets at the apex. Spikelets cuneate; laterally compressed; 4-6.887-14 mm long; falling entire (2), or breaking up at maturity (6); deciduous with accessory branch structures (2/2); disarticulating below each fertile floret (6/6). Rhachilla internodes glabrous (5), or pilose (3). Floret callus pubescent (6/7), or pilose (1/7).

Fertile

Spikelets comprising 4 fertile florets (4), or 5-6 fertile florets, or 7-8 fertile florets (4), or 9 fertile florets (2); with diminished florets at the apex. Spikelets cuneate; laterally compressed; 4-6.887-14 mm long; falling entire (2), or breaking up at maturity (6); deciduous with accessory branch structures (2/2); disarticulating below each fertile floret (6/6). Rhachilla internodes glabrous (5), or pilose (3). Floret callus pubescent (6/7), or pilose (1/7).

Morphology Reproductive morphology Inflorescences Bracts Glume

Glumes persistent (6/6); shorter than spikelet (5), or reaching apex of florets (4), or exceeding apex of florets (1); gaping. Lower glume linear (2), or lanceolate (7), or oblong (1); 0.75-0.9125-1.2 length of upper glume; membranous; without keels (2), or 1-keeled (6); 1 -veined. Lower glume lateral veins absent. Lower glume surface smooth (3), or asperulous (2), or scabrous (3). Lower glume apex acute (1), or acuminate (1), or attenuate (5), or setaceously attenuate (1); muticous (5), or awned (3). Upper glume linear (1), or lanceolate (6), or elliptic (1), or oblong (1); 1.25-1.778-2.3 length of adjacent fertile lemma; membranous; without keels (2), or 1-keeled (6); 1 -veined. Upper glume surface smooth (3), or asperulous (2), or scabrous (3). Upper glume apex acute (1), or acuminate (1), or attenuate (5), or setaceously attenuate (1); muticous (5), or awned (3); 1 -awned (3/3).

Morphology Reproductive morphology Flowers Florets

Fertile lemma elliptic (1), or oblong; membranous; without keel (2), or keeled; 3 -veined. Lemma midvein without distinctive roughness (7), or scaberulous (1). Lemma surface glabrous (4), or puberulous (1), or pilose (3). Lemma margins ciliate. Lemma apex dentate; 2 -fid; obtuse (3/3); mucronate (1), or awned (7); 1 -awned (7/7). Principal lemma awn apical (1), or from a sinus (7). Palea 1 length of lemma; 2 -veined. Palea surface glabrous (7), or pubescent (3). Apical sterile florets resembling fertile though underdeveloped.

Morphology Reproductive morphology Flowers

Anthers 3 (7/7).

Morphology Reproductive morphology Fruits

Caryopsis with adherent pericarp (3/3); linear (1/3), or lanceolate (1/3), or ellipsoid (2/3), or oblong (2/3); dorsally compressed (3/3); plano-convex (3/3), or concavo-convex (3/3).

Distribution

Africa (5), or Temperate Asia (1), or North America (1), or South America (2).