Helianthus laevigatus

Torrey & A. Gray

Fl. N. Amer. 2: 330. 1842.

Common names: Smooth sunflower
Endemic
Synonyms: Helianthus laevigatus subsp. reindutus E. S. Steele Helianthus reindutus
Treatment appears in FNA Volume 21. Treatment on page 158. Mentioned on page 145, 159.

Perennials, 100–220 cm (rhizomatous). Stems erect, usually glabrous, sometimes proximally hirsute (glaucous). Leaves cauline; opposite (proximal) or alternate; sessile or subsessile; blades (grayish green or bluish green) lanceolate, 8–15 × 1.5–3.5 cm, bases ± cuneate, margins serrate to subentire, abaxial faces glabrous or glabrate (smooth or slightly rough to touch, glaucous). Heads 1–6. Peduncles 2–8 cm. cm. Involucres cylindric, 10–15 mm diam. Phyllaries 23–28, lanceolate, 6–13 × 2–3 mm, (margins sometimes ciliate) apices acuminate, abaxial faces glabrous, not glanddotted. Paleae 8.5–10 mm, 3-toothed to subentire. Ray-florets 5–10; laminae 15–20 mm. Disc-florets 35+; corollas 5.5–6.5 mm, lobes yellow; anthers dark, appendages dark. Cypselae 4–5.5 mm, glabrous; pappi of 2 aristate scales 3.2–4.1 mm plus 0–1 deltate scales 0.5–1.1 mm. 2n = 68.


Phenology: Flowering late summer–fall.
Habitat: Shale barrens
Elevation: 300–900+ m

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Helianthus laevigatus"
glabrous +  and glabrate +
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 +
8 cm80 mm <br />0.08 m <br /> (15 cm150 mm <br />0.15 m <br />) +
lanceolate +
1.5 cm15 mm <br />0.015 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Smooth sunflower +
reddish +  and yellow +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
compressed +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
N.C. +, S.C. +, Va. +  and W.Va. +
300–900+ m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Shale barrens +
in more or less corymbiform , paniculiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
subsessile +  and sessile +
alternate +  and opposite +
triangular +
serrate +  and entire +
serrate +  and subentire +
2-carpellate +
3-toothed;subentire +
0.85 cm8.5 mm <br />0.0085 m <br /> (1 cm10 mm <br />0.01 m <br />) +
persistent +
0 +  and 1 +
coroniform +
2 cm20 mm <br />0.02 m <br /> (8 cm80 mm <br />0.08 m <br />) +
Flowering late summer–fall. +
0.6 cm6 mm <br />0.006 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
23 +  and 28 +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Fl. N. Amer. +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
deltate +  and aristate +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.11 cm1.1 mm <br />0.0011 m <br />) +
exalbuminous +
procumbent +  and decumbent +
hirsute +  and glabrous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Helianthus laevigatus subsp. reindutus +  and Helianthus reindutus +
Helianthus laevigatus +
Helianthus +
species +
campanulate +
toothed +  and entire +
300 cm3,000 mm <br />3 m <br /> (500 cm5,000 mm <br />5 m <br />) +
100 cm1,000 mm <br />1 m <br /> (220 cm2,200 mm <br />2.2 m <br />) +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
shrub +  and subshrub +