Parthenium confertum |
Parthenium integrifolium |
|
---|---|---|
gray feverfew, Gray's feverfew |
American feverfew, wild feverfew, wild quinine |
|
Habit | Biennials (sometimes flowering first year or persisting), 10–30(–60+) cm. | Perennials, 30–60(–100+) cm. |
Leaf | blades ovate or rounded-deltate to elliptic, 30–80(–120+) × 10–20(–40+) mm, usually ± pinnately or sub-bipinnately lobed, ultimate margins entire, faces strigillose, usually also with erect hairs 1–2 mm and gland-dotted. |
blades ovate to lanceolate, 30–350+ × 20–120+ mm, margins usually crenate to serrate, sometimes coarsely toothed or somewhat lobed (then mostly toward bases), faces hispid to hirtellous or ± scabrous, gland-dotted. |
Peduncles | 2–8(–12+) mm. |
1–8(–12+) mm. |
Pistillate florets | 5; corolla laminae 0 or ± coroniform, 0.1–0.5 mm. |
5(–6); corolla laminae ovate to oblong or orbiculate, 1–2+ mm. |
Disc florets | 20–30+. |
15–35+. |
Phyllaries | outer 5 lance-ovate to elliptic, 2.5–3+ mm, inner 5 ± orbiculate, 3–3.5 mm. |
outer 5(–6) lanceolate to broadly ovate, 3–5 mm, inner 5(–6) ± orbiculate, 4–6 mm. |
Heads | disciform or obscurely radiate, borne in open, ± paniculiform arrays. |
radiate, borne in corymbiform to paniculiform arrays. |
Cypselae | ± obovoid, 2–3 mm; pappus-like enations 2, ± erect, deltate to ovate, 0.5–1 mm (sometimes a third, subulate spur near apex adaxially). |
± obovoid, 3–4+ mm; pappus-like enations 0 or 2(–4), erect to spreading, ± subulate or threadlike, fragile, 0.3–0.6+ mm. |
2n | = 36, 68, 72. |
= 72. |
Parthenium confertum |
Parthenium integrifolium |
|
Phenology | Flowering Mar–Oct. | Flowering May–Sep. |
Habitat | Sandy plains, openings in mesquite grasslands | Glades and barrens, prairies, disturbed sites |
Elevation | 20–2000 m (100–6600 ft) | 10–500 m (0–1600 ft) |
Distribution |
AZ; NM; TX; Mexico
|
AL; AR; CT; GA; IA; IL; IN; KS; KY; LA; MA; MI; MN; MO; MS; NC; NY; OH; OK; PA; SC; TN; TX; VA; WI; WV
|
Discussion | As evidenced by the synonymy, Parthenium integrifolium as here circumscribed has been variously partitioned by other taxonomists. For the present, I see no justification for segregating species from, or for formal recognition of infraspecific taxa within P. integrifolium. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
|
Source | FNA vol. 21, p. 22. | FNA vol. 21, p. 22. |
Parent taxa | Asteraceae > tribe Heliantheae > subtribe Ambrosiinae > Parthenium | Asteraceae > tribe Heliantheae > subtribe Ambrosiinae > Parthenium |
Sibling taxa | ||
Synonyms | P. confertum var. divaricatum, P. confertum var. lyratum, P. confertum var. microcephalum | P. auriculatum, P. hispidum, P. hispidum var. auriculatum, P. integrifolium var. auriculatum, P. integrifolium var. henryanum, P. integrifolium var. hispidum, P. integrifolium var. mabryanum, P. radfordii |
Name authority | A. Gray: Proc. Amer. Acad. Arts 17: 216. (1882) | Linnaeus: Sp. Pl. 2: 988. (1753) |
Web links |