Silphium integrifolium var. integrifolium
Family: Asteraceae
Whole-Leaf Rosinweed
[Silphium integrifolium var. deamii L. M. Perry,  more...]
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Plants 40-200 cm. Leaves: blades scabrous, pilose, hispid, or glabrous. Phyllaries: abaxial faces usually hispid, pilose, or scabrous, rarely glabrous. Ray florets 12-22. Disc florets 70-140. 2n = 14.

Flowering mid summer-early fall. Prairies, along roads and railroads; 50-600 m; Ala., Ark., Ill., Ind., Iowa, Kans., Ky., La., Mich., Miss., Mo., Nebr., Okla., S.Dak., Tenn., Wis.

From Flora of Indiana (1940) by Charles C. Deam

Infrequent to rare, rarely frequent, throughout Indiana although there are no records from the northeastern part. It is generally found in dry soil on open wooded slopes, frequent in prairie habitats, and on the low wooded dunes along Lake Michigan. The plants are variable in the width and margins of the leaves and in the pubescence of the stem, leaves, and involucre. Some plants have stems with a few ternate or alternate leaves. The inner face of the achenes is either glabrous or pubescent, mostly more or less pubescent. I have had all forms of this species under cultivation for many years to study them. [Plants with glandular pubescence on the involucral bracts are called var. deamii. It is] found throughout the range of the species but rarely found closely associated with it in Indiana.

The more hairy phase; peduncles, backs of the invol bracts, and usually also the lower surfaces of the lvs and at least the upper part of the stem velvety or scabrous (most of or all the hairs ca 0.5 mm or less); typically in the tall-grass prairie.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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