Stem at anthesis to 1 m, much branched; lvs deltoid, the numerous ultimate segments linear to cuneate-obovate, variously toothed or lobed; umbels 5-8 cm wide, the rays about equal; pet yellow or greenish-yellow; fr 2-4 mm; 2n=22. Native of the Mediterranean region, occasionally escaped from cult. in our range. (P. hortense; Apium petroselinum)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.