Iva annua
Sp. Pl. 2: 988. 1753.
Synonyms: Iva annua var. caudata (Small) R. C. Jackson Iva annua var. macrocarpa (S. F. Blake) R. C. Jackson
Annuals, (10–)50–100(–150+) cm. Stems erect. Leaves: petioles 5–20(–30) mm; blades deltate or ovate to elliptic, trullate, or lanceolate, 30–100(–150)+ × 8–45(–80) mm, margins ± toothed, faces ± scabrellous, gland-dotted. Heads in ± spiciform arrays. Peduncles 0–1 mm. Involucres ± hemispheric, 3–4(–5) mm. Phyllaries: outer 3–5 distinct, ± herbaceous. Paleae linear, 2–2.5 mm. Pistillate florets 3–5; corollas 0.5–1 mm. Functionally staminate florets 8–12+; corollas 2–2.5 mm. Cypselae 2–3 mm. 2n = 34.
Phenology: Flowering Jul–Nov.
Habitat: Disturbed sites, moist soils
Elevation: 10–500 m
Distribution
Ala., Ark., Colo., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Mich., Miss., Mo., Nebr., N.Mex., N.C., N.Dak., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Va., W.Va., Wis., Mexico (Tamaulipas).
Discussion
Selected References
None.
Lower Taxa
None.