Kidneyleaf Rosinweed

Plants scapiform, 50–250 cm; taprooted. Stems terete, glabrous (sometimes glaucous). Leaves: basal persistent, petiolate; cauline alternate, petiolate or sessile; blades cordate, deltate, elliptic, hastate, ovate, reniform, or sagittate, 2–35 × 0.5–52 cm, sometimes (proximal) pinnately or palmately lobed, bases oblique, truncate, attenuate, cordate, sagittate, or hastate, ultimate margins toothed, apices acute, faces glabrous, hispid, or scabrous. Phyllaries 11–18 in 2–3 series, outer appressed to reflexed, apices obtuse to cuspidate, abaxial faces sparsely scabrous. Ray florets 6–12; corollas yellow. Disc florets 20–85; corollas yellow. Cypselae 6–12 × 4–10 mm; pappi 1–4 mm. 2n = 14.

Silphium compositum subsp. ovatifolium (Torrey & A. Gray) C. R. Sweeney & T. R. Fisher; S. compositum subsp. reniforme (Rafinesque ex Nuttall) C. R. Sweeney & T. R. Fisher; S. compositum var. reniforme (Rafinesque ex Nuttall) Torrey & A. Gray; S. compositum subsp. venosum (Small) C. R. Sweeney & T. R. Fisher; S. compositum var. venosum (Small) Kartesz & Gandhi; S. lapsuum Small; S. orae Small; S. ovatifolium (Torrey & A. Gray) Small; S. reniforme Rafinesque ex Nuttall; S. venosum Small

Silphium compositum, the kidney-leaf rosinweed, is a flowering plant in the family Asteraceae. A perennial in the Silphium genus, it has yellow flowers and is deciduous. It grows in the southeastern United States. It has divided basal leaves.