Helianthus microcephalus

Torrey & A. Gray
Fl. N. Amer. 2: 329. 1842.
Common names: Woodland sunflower
Endemic
Treatment appears in FNA Volume 21. Treatment on page 163. Mentioned on page 145, 157, 158, 159.

Perennials, 20–200 cm (with crown buds). Stems erect, glabrous. Leaves cauline; opposite or alternate; petioles 0.3–3 cm; blades (greenish, at least abaxially, 3-nerved at bases) lanceolate, 7.2–15.5 × 1.3–4 cm, bases cuneate, margins entire or serrate, abaxial faces tomentulose, densely gland-dotted. Heads (1–)3–15+. Peduncles 1–3(–8) cm. Involucres cylindric, 5–7 mm diam. Phyllaries 12–17, lance-linear, 3–6.5 × 1.5–2.5 mm, (margins ciliate) apices acuminate, abaxial faces glabrate, not gland-dotted. Paleae 5–7 mm, 3-toothed (apices hairy). Ray florets 5–8; laminae 10–14 mm. Disc florets 15–22; corollas 4–5.5 mm, lobes yellow; anthers dark, appendages dark. Cypselae 3.5–4.2 mm, glabrous; pappi of 2 aristate scales 1.5–2.2 mm. 2n = 34.


Phenology: Flowering late summer–fall.
Habitat: Open woodlands, shaded roadsides
Elevation: 10–900 m

Distribution

V21-392-distribution-map.gif

Ala., Ark., Conn., D.C., Fla., Ga., Ill., Ind., Iowa, Ky., La., Md., Mich., Minn., Miss., N.J., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va.

Discussion

Helianthus microcephalus is distinguished by its relatively small heads, which have relatively few phyllaries, ray florets, and disc florets, as well as the usually tomentulose abaxial faces of the leaves. Hybrids with H. divaricatus are known.

Selected References

None.

Lower Taxa

None.

... more about "Helianthus microcephalus"
Edward E. Schilling +
Torrey & A. Gray +
Woodland sunflower +
Ala. +, Ark. +, Conn. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Ky. +, La. +, Md. +, Mich. +, Minn. +, Miss. +, N.J. +, N.C. +, Ohio +, Pa. +, S.C. +, Tenn. +, Va. +  and W.Va. +
10–900 m +
Open woodlands, shaded roadsides +
Flowering late summer–fall. +
Fl. N. Amer. +
Undefined (tribe Undefined) subtribe Lagasceinae +
Helianthus microcephalus +
Helianthus +
species +