Silphium asteriscus var. latifolium

(A. Gray) J. A. Clevinger

Novon 14: 276. 2004.

Endemic
Basionym: Silphium trifoliatum var. latifolium A. Gray in A. Gray et al, Syn. Fl. N. Amer. 1(2): 241. 1884
Synonyms: Silphium confertifolium Small Silphium glabrum Eggert
Treatment appears in FNA Volume 21. Treatment on page 82. Mentioned on page 81.

Plants 50–150 cm. Leaves: basal persistent or caducous; cauline mostly opposite; faces glabrous or sparsely hairy. Paleae puberulent. Ray-florets 12–17. Disc-florets 35–130.


Phenology: Flowering mid summer–early fall.
Habitat: Fields, roadsides, disturbed areas
Elevation: 100–900 m

Distribution

V21-190-distribution-map.gif

Ala., Ga., Ky., La., Miss., N.C., S.C., Tenn., Va., W.Va.

Discussion

Silphium confertifolium has persistent basal leaves and a diminutive stature that is due to environmental variation; it is best included in S. asteriscus var. latifolium.

Selected References

None.

Lower Taxa

None.

"broader" is not a number.

scabrous +  and hispid +
not tailed +, rounded +  and obtuse +
connate +  and distinct +
acute;acuminate +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
racemiform +  and paniculiform +
indeterminate +  and determinate +
Jennifer A. Clevinger +
(A. Gray) J. A. Clevinger +
bristlelike +
coroniform +
sessile +  and petiolate +
caducous +  and persistent +
attenuate +  and round +
Silphium trifoliatum var. latifolium +
1.5 cm15 mm <br />0.015 m <br /> (25 cm250 mm <br />0.25 m <br />) +
ovate;falcate;ovate;falcate;lanceolate +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
sessile +  and petiolate +
0.6 cm6 mm <br />0.006 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
hairy +  and glabrous +
less orbiculate +  and obovate or cuneate +
0.4 cm4 mm <br />0.004 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
fertile +  and bisexual +
fertile +  and bisexual +
Ala. +, Ga. +, Ky. +, La. +, Miss. +, N.C. +, S.C. +, Tenn. +, Va. +  and W.Va. +
100–900 m +
hairy +  and glabrous +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Fields, roadsides, disturbed areas +
in cymiform , corymbiform , paniculiform , racemiform or spiciform , arrays +  and singly +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
campanulate;hemispheric +
sessile +  and petiolate +
alternate +, subopposite +, opposite +  and whorled +
cauline +  and basal +
deltate +
entire +, serrate +  and dentate +
toothed +  and entire +
reflexed +  and appressed +
2-carpellate +
persistent +
0 cm0 mm <br />0 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering mid summer–early fall. +
12 +  and 26 +
unequal +  and subequal +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
exalbuminous +
scabrous +, hispid +, hirsute +  and glabrous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Silphium confertifolium +  and Silphium glabrum +
Silphium asteriscus var. latifolium +
Silphium asteriscus +
variety +
cylindric +
cylindric +
shorter to longer than campanulate +
toothed +  and entire +
20 cm200 mm <br />0.2 m <br /> (250 cm2,500 mm <br />2.5 m <br />) +
fibrous-rooted +  and caulescent +
200 cm2,000 mm <br />2 m <br /> (400 cm4,000 mm <br />4 m <br />) +