Helianthus occidentalis subsp. occidentalis

Endemic
Synonyms: Helianthus dowellianus M. A. Curtis Helianthus occidentalis var. dowellianus (M. A. Curtis) A. Gray
Treatment appears in FNA Volume 21. Treatment on page 160.

Leaves entire or nearly so, scabrous or hirsute, rough to touch.


Phenology: Flowering late summer–fall.
Habitat: Fields, barrens
Elevation: 10–600+ m

Distribution

V21-383-distribution-map.gif

Ark., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Md., Mass., Mich., Mo., N.J., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va., Wis.

Discussion

In its typical form, Helianthus occidentalis is distinctive with its relatively few basal leaves and scapiform stems. Still unresolved is the status of H. dowellianus, which may deserve recognition at some level. These plants have the head morphology of H. occidentalis but have multiple pairs of well-developed cauline leaves. Plants with this morphology are found in the southern Appalachian region from Maryland to Georgia. According to C. B. Heiser et al. (1969), these plants may be hybrids of H. occidentalis and H. atrorubens. Natural hybrids of H. occidentalis with H. mollis have been called H. ×cinereus Torrey & A. Gray. Hybrids of H. occidentalis with other species are known.

Selected References

None.

Lower Taxa

None.
glabrate +  and sparsely pilose +
not tailed +, rounded +  and obtuse +
black +  and dark-brown +
pale +  and dark +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
spiciform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Edward E. Schilling +
Riddell +
cuneate +
5 cm50 mm <br />0.05 m <br /> (20 cm200 mm <br />0.2 m <br />) +
elliptic;ovate +
1.5cm;7cm +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
reddish +  and yellow +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
glabrate +  and villous +
compressed +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
Ark. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, Md. +, Mass. +, Mich. +, Mo. +, N.J. +, N.C. +, Ohio +, Pa. +, S.C. +, Tenn. +, Va. +, W.Va. +  and Wis. +
10–600+ m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Fields, barrens +
in more or less corymbiform , paniculiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.9 cm9 mm <br />0.009 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
1.8 cm18 mm <br />0.018 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
sessile +  and petiolate +
nearly +  and entire +
hirsute +  and scabrous +
triangular +
serrulate +  and entire +
2-carpellate +
subentire;3-toothed +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
persistent +
0 +  and 4 +
coroniform +
1 cm10 mm <br />0.01 m <br /> (14 cm140 mm <br />0.14 m <br />) +
2.5 cm25 mm <br />0.025 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Flowering late summer–fall. +
0.7 cm7 mm <br />0.007 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
20 +  and 25 +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
W. J. Med. Phys. Sci. +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
deltate +  and aristate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
exalbuminous +
procumbent +  and decumbent +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Helianthus dowellianus +  and Helianthus occidentalis var. dowellianus +
Helianthus occidentalis subsp. occidentalis +
Helianthus occidentalis +
subspecies +
campanulate +
toothed +  and entire +
300 cm3,000 mm <br />3 m <br /> (500 cm5,000 mm <br />5 m <br />) +
60 cm600 mm <br />0.6 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
shrub +  and subshrub +