Flaveria trinervia |
Flaveria campestris |
|
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cluster yellow tops |
alkali yellowtops |
|
Habit | Annuals, to 200+ cm (delicate or robust, glabrate or glabrous). | Annuals, 18–70(–90) cm (delicate or robust, mostly glabrous). |
Stems | erect. |
usually erect (tufted-pubescent at nodes). |
Leaves | petiolate (proximal, petioles 10–20 mm) or sessile (distal); blades lanceolate or oblanceolate to elliptic or subovate, 30–150 × (7–)10–40 mm, bases (distal) connate, margins serrate, serrate-dentate, or spinulose-serrate. |
sessile; bladeslinear-lanceolate to lanceolate, 30–90 × 6–22 mm, bases barely connate, margins strongly to weakly serrate or spinulose-serrate. |
Involucres | oblong and cylindric or angular, 3.8–4.5 mm. |
urceolate or oblong, 6–7 mm. |
Ray florets | 0–1; laminae pale yellow or whitish, oblique or suborbiculate, 0.5–1 mm. |
0 or 1, laminae yellow, ovate, 1.5–2.5 mm (apices notched). |
Disc florets | 0–1(–2); corolla tubes 0.5–1.4 mm, throats campanulate, 0.5–0.8 mm. |
5–6(–8);, corolla tubes 0.8–1.3 mm, throats funnelform, 1.2–1.7 mm. |
Phyllaries | usually 2, oblong (closely investing and falling with mature cypselae). |
3, elliptic, obovate, or oblong-obovate. |
Calyculi | 0. |
of 2 linear-lanceolate bractlets 1–3 mm. |
Heads | 30–300+, in tight, axillary, sessile glomerules (receptacles of glomerules setose). |
(10–)15–100+, in tight subglomerules in corymbiform arrays. |
Cypselae | oblanceoloid to subclavate, 2–2.6 mm (rays longer); pappi 0. |
oblanceolate, linear, or oblong, 2.8–3.6 mm (those of rays longer by ca. 0.2 mm), pappi 0. |
2n | = 36. |
= 36 (18). |
Flaveria trinervia |
Flaveria campestris |
|
Phenology | Flowering Mar–Dec. | Flowering May–Nov. |
Habitat | Near water, saline and gypseous areas | Saline soils, lake, pond, stream margins, flood plains, and disturbed pastures |
Elevation | 0–1900 m (0–6200 ft) | 1000–1800 m (3300–5900 ft) |
Distribution |
AZ; CA; FL; MA; MO; NM; TX; VA; HI; West Indies; Central America (British Honduras); South America (Brazil, Ecuador, Peru, Venezuela); Africa [Probably introduced in Asia (India, Middle East)]
|
AZ; CO; KS; MO; NM; OK; TX; UT
|
Discussion | Flaveria trinervia is widespread and weedy; it often occurs in saline, gypseous, disturbed areas near permanent or ephemeral water sources in southern Florida and from Texas to southern California. It occurs also in scattered locations in some eastern states and has been reported from Alabama. The heads of Flaveria trinervia, which usually contain just one floret, are either radiate or discoid; radiate heads tend to occur on the periphery of setose glomerules. Reduction of some of the floral features, including number of florets [0–1(–2)], phyllaries per head (2), and size of ray laminae, suggest that F. trinervia may be the most derived species in the genus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Flaveria campestris is distinguished by subglomerulate capitulescences with 5–6(–8) florets per head, subtended by 3 leafy bracts, keeled phyllaries, and linear-lanceolate leaves with serrate or spinulose-serrate margins, and its distribution. The prevalence of F. campestris fluctuates greatly from year to year, generally depending on the existence of wet, saline habitat. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 21, p. 250. | FNA vol. 21, p. 250. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Flaveriinae > Flaveria | Asteraceae > tribe Heliantheae > subtribe Flaveriinae > Flaveria |
Sibling taxa | ||
Synonyms | Odera trinervia | |
Name authority | (Sprengel) C. Mohr: Contr. U.S. Natl. Herb. 6: 810. (1901) | J. R. Johnston: Proc. Amer. Acad. Arts 39: 287. (1903) |
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