Parthenium integrifolium

Linnaeus

Sp. Pl. 2: 988. 1753.

IllustratedEndemic
Synonyms: Parthenium auriculatum Britton Parthenium hispidum Rafinesque Parthenium hispidum var. auriculatum (Britton) Rollins Parthenium integrifolium var. auriculatum (Britton) Cornelius ex Cronquist Parthenium integrifolium var. henryanum Mears Parthenium integrifolium var. hispidum (Rafinesque) Mears Parthenium integrifolium var. mabryanum Mears Parthenium radfordii
Treatment appears in FNA Volume 21. Treatment on page 22. Mentioned on page 20.

Perennials, 30–60(–100+) cm. Leaf 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. Heads radiate, borne in corymbiform to paniculiform arrays. Peduncles 1–8(–12+) mm. Phyllaries: outer 5(–6) lanceolate to broadly ovate, 3–5 mm, inner 5(–6) ± orbiculate, 4–6 mm. Pistillate florets 5(–6); corolla laminae ovate to oblong or orbiculate, 1–2+ mm. Disc florets 15–35+. Cypselae ± obovoid, 3–4+ mm; pappus-like enations 0 or 2(–4), erect to spreading, ± subulate or threadlike, fragile, 0.3–0.6+ mm. 2n = 72.


Phenology: Flowering May–Sep.
Habitat: Glades and barrens, prairies, disturbed sites
Elevation: 10–500 m

Distribution

V21-34-distribution-map.gif

Ala., Ark., Conn., Ga., Ill., Ind., Iowa., Kans., Ky., La., Mass., Mich., Minn., Miss., Mo., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., W.Va., Wis.

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.

Selected References

None.

Lower Taxa

None.
... more about "Parthenium integrifolium"
John L. Strother +
Linnaeus +
Ala. +, Ark. +, Conn. +, Ga. +, Ill. +, Ind. +, Iowa. +, Kans. +, Ky. +, La. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, N.Y. +, N.C. +, Ohio +, Okla. +, Pa. +, S.C. +, Tenn. +, Tex. +, Va. +, W.Va. +  and Wis. +
10–500 m +
Glades and barrens, prairies, disturbed sites +
Flowering May–Sep. +
Illustrated +  and Endemic +
Parthenium auriculatum +, Parthenium hispidum +, Parthenium hispidum var. auriculatum +, Parthenium integrifolium var. auriculatum +, Parthenium integrifolium var. henryanum +, Parthenium integrifolium var. hispidum +, Parthenium integrifolium var. mabryanum +  and Parthenium radfordii +
Parthenium integrifolium +
Parthenium +
species +