Arisaema triphyllum (L.) Schott
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Corm very acrid; lvs mostly 2, the petiole 3–6 dm at anthesis, sometimes later to 15 dm; lfls 3, acuminate, the terminal elliptic to rhombic-ovate, the lateral often asymmetrical; veins of the lfls parallel from the midrib to the marginal vein, connected by numerous anastomosing veinlets; peduncle 3–20 cm; spathe convolute below, expanded above and arched over the spadix, abruptly acuminate; spadix cylindric or barely clavate, yellow, blunt; fr 1 cm; 2n=28, 56. N.S. to N.D., s. to Fla. and Tex. Spring.
Jack-in-the-pulpit, Indian turnip