Silphium integrifolium
Silphium radula
entire-leaf rosinweed, prairie rosinweed, whole-leaf rosinweed
roughleaf rosinweed, roughstem rosinweed, starry rosinweed
terete to slightly square, sparsely scabrous or glabrous (sometimes glaucous).
terete, scabrous, hispid, or hirsute.
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.
basal persistent or caducous, petiolate;
cauline alternate or opposite, petiolate or sessile;
blades lanceolate to ovate, 2–22 × 0.5–8 cm, bases attenuate to round, margins coarsely dentate or entire, apices acuminate to acute, faces scabrous, hispid, or hirsute.
12–36;
corollas yellow.
12–30+;
corollas yellow.
70–225;
corollas yellow.
100–175;
corollas yellow.
17–37 in 2–3 series, outer appressed, apices acute to acuminate, abaxial faces glabrous, hispid, pilose, or scabrous, sometimes stipitate-glandular.
18–37 in 2–4 series, outer appressed or reflexed, apices acute, abaxial faces scabrous.
9–14 × 6–10 mm;
pappi 1–4 mm.
10–17 × 7–15 mm;
pappi 2–5 mm.
Silphium integrifolium
Silphium radula
Varieties 2 (2 in flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Phyllaries: abaxial faces usually hispid, pilose, or scabrous, rarely glabrous; ray florets 12–22 | var. integrifolium |
1. Phyllaries: abaxial faces glabrous; ray florets 20–36+ | var. laeve |
1. Basal leaves caducous; ray florets 20–30+ | var. radula |
1. Basal leaves persistent; ray florets 12–18 | var. gracile |
IL Wildflowers
KS Wildflowers
LA Plants
MI Flora
MO Plants
WildflowerSearch
iNaturalist
USDA Plants Database
