Trixis divaricata (Kunth) Spreng.
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Authority
Anderson, Christiane. 1972. A monograph of the Mexican and Central American species of Trixis (Compositae). Mem. New York Bot. Gard. 22: 1-68.
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Family
Asteraceae
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Scientific Name
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Description
Species Description - A weak, scandent, flexuose shrub. Stems not winged; young branches and inflorescence hirsute. Leaves sessile or short-petiolate; blades linear-lanceolate, acuminate at the apex, auriculate or rarely attenuate at the base, strigose above, villous beneath; margins denticulate, rarely entire, slightly recurved or revolute. Inflorescence a divaricate, leafy, compound panicle; peduncles 0.5-3 cm long, usually curved; the heads usually nodding. Accessory bracts 5-7, up to three-fourths as long as the phyllaries, linear with an acute apex or subulate, sessile. Phyllaries 8, 10-13 mm long, 1.3-2 mm wide, linear with a short-acuminate apex or subulate, convex or slightly keeled. Flowers (10-) 12-14. Outer hp of the coroha of the outer flowers 3.5-4 mm long, 1.5-2 mm wide, usually revolute but sometimes only recurved. Achenes covered with glandular trichomes (80-) 100-140 µ long; double hairs absent. Pappus ca. 10 mm long, tawny.
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Discussion
Perdicium divaricatum HBK., Nov. Gen. Sp. 4: 155, pl. 355. 1820.
Type. Peru: Prope Cavico ad ripam fluvii Chamaya, Humboldt & Bonpland (P, holotype).
This species is one of the South American frutescent taxa and is included here because it occurs in Central America and the West Indies. Its range extends from Argentina north to Costa Rica; it has also been collected on Hispaniola. T. divaricata is readily distinguished by the lax, divaricate or flexuose inflorescence whose nodding heads are borne on slender, curved peduncles. The leaves are usually auriculate at the base though some collections from Santo Domingo lack these auricles. The achenes differ from those of northern species of Trixis in that they lack the double hairs though occasionally an achene does bear one that does not release mucilage when wetted.