Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Genus Description - Ordinarily dioecious; pistillate fls in small clusters on short, leafy branches from the upper axils, each fl semi-enclosed by a closely subtending, abruptly acuminate bract; cal short and barely lobed, or sometimes longer but hyaline and becoming adnate to the pericarp; fr a thick-lenticular achene, with a closely subtending accrescent bract; erect annual herbs; lvs petiolate, the principal ones palmately compound with 5–9 lfls, commonly opposite, the upper smaller, usually alternate, with fewer lfls or undivided. Monospecific.
hemp, Indian hemp