Trollius laxus Salisb.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Stem 1–5 dm; basal lvs long-petioled, cauline 1–3, chiefly above the middle, sessile or subsessile and often approximate; blades subrotund, 3–5-parted with 3-lobed and coarsely toothed, cuneate-obovate segments; sep 5–7, greenish-yellow to bright yellow or cream, elliptic, 15–20 mm, at first incurved-ascending; staminodes oblong, 3–5 mm; follicles 1 cm; 2n=32. Swamps, wet woods and wet meadows; Conn. to Del., Pa., and O. Apr.–June.