《Flora of North America》|| Asteraceae || || Flaveria

327. Flaveria Jussieu, Gen. Pl. 186. 1789.

[Latin flavus, yellow]

Sharon C. Yarborough, A. Michael Powell

Annuals, perennials, or subshrubs, to 200+ cm [trees to 400 cm] (usually ± succulent, herbage usually glaucous). Stems (often purplish) erect or decumbent, branched distally or ± throughout. Leaves cauline; opposite (decussate); petiolate or sessile (weakly connate to connate-perfoliate); blades (often 3-nerved) oblong-ovate to lanceolate or linear, margins entire, serrate, or spinulose-serrate, faces glabrous or short-pubescent. Heads radiate or discoid, usually in tight or loose aggregations in (often flat-topped) ± corymbiform arrays or glomerules. Involucres oblong, urceolate, cylindric, or turbinate, 0.5–2 mm diam. Phyllaries persistent, 2–6(–9) in ± 1 series (linear, concave, or boat-shaped, subequal). Receptacles convex, epaleate ("receptacles" of glomerules sometimes setose). Ray florets 0–1(–2), pistillate, fertile; corollas yellow or whitish (laminae inconspicuous). Disc florets 1–15, bisexual, fertile; corollas yellow, tubes shorter than to about equaling funnelform to campanulate throats, lobes 5, ± deltate. Cypselae (black) weakly compressed, narrowly oblanceolate or linear-oblong (usually 10-nerved, glabrous); pappi usually 0, sometimes persistent, of 2–4 hyaline scales, or coroniform (of connate scales). x = 18.

Species 21 (8 in the flora): United States, Mexico, West Indies (Greater Antilles), Central America, South America, Asia (India), Africa, Australia.

Members of Flaveria are frequently found in alkaline, saline, and gypseous soils, often in disturbed and moist areas. Heads of Flaveria may be either radiate or discoid; when both are present in the same capitulescence, the discoid heads tend to be central and the radiate heads peripheral. Many species of Flaveria have persistent sheathing leaf bases that ring the stems after the leaves have fallen.

Flaveria is notable because certain species exhibit C3 photosynthesis, some C3–C4 (intermediate) photosynthesis, and others (F. brownii, F. bidentis, F. campestris, and F. trinervia in the United States) classic C4 photosynthesis.

SELECTED REFERENCE

Powell, A. M. 1978. Systematics of Flaveria (Flaveriinae–Asteraceae). Ann. Missouri Bot. Gard. 65: 590–636.

《Flora of China》|| Asteraceae || ||黄顶菊属 Flaveria

204. Flaveria Jussieu, Gen. Pl. 186. 1789.

黄顶菊属 huang ding ju shu

Annuals, perennials, or subshrubs. Stems erect or decumbent, branched. Leaves cauline, opposite, petiolate or sessile; blade oblong-ovate to lanceolate or linear, both surfaces glabrous or shortly pubescent, margin entire or serrate, or spinulose-serrate. Synflorescences of lax or dense aggregations of capitula in corymbose panicles or glomerules. Capitula radiate or discoid; involucres oblong, urceolate, cylindric, or turbinate, 0.5-2 mm in diam.; phyllaries persistent, 2-6(-9), 1-seriate; receptacle small, convex, epaleate. Ray florets 0 or 1(or 2), female, fertile, when present external to clusters of capitula; corollas yellow or whitish. Disk florets 1-15, bisexual, fertile; corollas yellow, tubes shorter than to ± equaling funnelform to campanulate throats, lobes 5, ± deltate. Achenes black, weakly compressed, narrowly oblanceolate or linear-oblong, ribbed, glabrous; pappus usually absent, or sometimes persistent, of 2-4 hyaline scales, or coroniform, or of connate scales. x = 18.

About 21 species: India, Mexico, United States; Africa, Australia, Caribbean, Central and South America; one species (introduced) in China.

See the revision of Flaveria by Powell (Ann. Missouri Bot. Gard. 65: 590-636. 1978).