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 glanddotted. 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 glanddotted. 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"
glabrate +  and tomentulose +
not tailed +, rounded +  and obtuse +
pale +  and dark +
connate +  and distinct +
acuminate +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
spiciform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Edward E. Schilling +
Torrey & A. Gray +
cuneate +
7.2 cm72 mm <br />0.072 m <br /> (15.5 cm155 mm <br />0.155 m <br />) +
lanceolate +
1.3 cm13 mm <br />0.013 m <br /> (4 cm40 mm <br />0.04 m <br />) +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Woodland sunflower +
reddish +  and yellow +
0.4 cm4 mm <br />0.004 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
compressed +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
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 +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Open woodlands, shaded roadsides +
in more or less corymbiform , paniculiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
sessile +  and petiolate +
alternate +  and opposite +
triangular +
serrate +  and entire +
2-carpellate +
3-toothed +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
persistent +
coroniform +
3 cm30 mm <br />0.03 m <br /> (8 cm80 mm <br />0.08 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (3 cm30 mm <br />0.03 m <br />) +
Flowering late summer–fall. +
0.3 cm3 mm <br />0.003 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
12 +  and 17 +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Fl. N. Amer. +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
aristate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
exalbuminous +
procumbent +  and decumbent +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Undefined (tribe Undefined) subtribe Lagasceinae +
Helianthus microcephalus +
Helianthus +
species +
campanulate +
toothed +  and entire +
300 cm3,000 mm <br />3 m <br /> (500 cm5,000 mm <br />5 m <br />) +
20 cm200 mm <br />0.2 m <br /> (200 cm2,000 mm <br />2 m <br />) +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
shrub +  and subshrub +