Silphium integrifolium

Michaux

Fl. Bor.-Amer. 2: 146. 1803.

Common names: Wholeleaf rosinweed
Treatment appears in FNA Volume 21. Treatment on page 80. Mentioned on page 77, 78, 81.
Revision as of 20:35, 16 December 2019 by FNA>Volume Importer

Plants caulescent, 40–200 cm; fibrous rooted. Stems terete to slightly square, sparsely scabrous or glabrous (sometimes glaucous). Leaves: basal caducous; cauline opposite, sessile; blades lanceolate to ovate, 2–23 × 0.1–11 cm, bases round to caudate, margins finely serrate or entire, apices acute to acuminate, faces hispid, scabrous, or glabrous. Phyllaries 17–37 in 2–3 series, outer appressed, apices acute to acuminate, abaxial faces glabrous, hispid, pilose, or scabrous, sometimes stipitate-glandular. Ray florets 12–36; corollas yellow. Disc florets 70–225; corollas yellow. Cypselae 9–14 × 6–10 mm; pappi 1–4 mm.

Discussion

Varieties 2 (2 in flora).

Selected References

None.

Key

1 Phyllaries: abaxial faces usually hispid, pilose, or scabrous, rarely glabrous; ray florets 12–22 Silphium integrifolium var. integrifolium
1 Phyllaries: abaxial faces glabrous; ray florets 20–36+ Silphium integrifolium var. laeve
... more about "Silphium integrifolium"
Jennifer A. Clevinger +
Michaux +
Wholeleaf rosinweed +
e North America. +
Fl. Bor.-Amer. +
Undefined (tribe Undefined) subtribe Enceliinae +, Undefined (tribe Undefined) subtribe Engelmanniinae +, Undefined (tribe Undefined) subtribe Spilanthinae +, Undefined (tribe Undefined) subtribe Verbesininae +  and Undefined (tribe Undefined) subtribe Zinniinae +
Silphium integrifolium +
Silphium +
species +