This is a weedy hexaploid (2n = 60) up to 2 m tall that is widely scattered across temperate North America, but rare to absent in southeastern states (K). The plant appears to have been used for its edible seed during the Woodland era (Ford 1985), and it was reported from pond sediments of similar age in LARU (Wilkins 1985). But see also notes under prolificum, which is closely related. FNA 5 reported typical ramosissimum from Ky., but no coll. has been located with confirmed identification (M). There is a suggestive immature coll. from OLDH (DHL), and a sight record from TRIM (M); but these records may well refer to prolificum instead. P. ramossissimum (sensu stricto) differs as follows (FNA 5, W): plants yellowish green when fresh (versus bluish green), not darkening when dried (versus turning dark brown to black); leaves acute to acuminate at apex (versus rounded to obtuse); pedicels 2.5-6 mm long (versus 1-2 mm); stem leaves 2.1-3.5 (-4.2) times as long as the branch leaves (versus 1-2.5 (-3.5) times).