Plains Sandparsley

Ammoselinum popei T. & G. Pacif. R. R. Rep. 2 4 : 165. 1855
Apium Popei A. Gray, Proc. Am. Acad. 7: 343. 1868.
Branching from the base, 1-3.5 dm. high; leaves oblong-ovate in general outline, excluding the petioles 1-4 cm. long, 1-4 cm. broad, ternate-pinnately dissected, the ultimate divisions linear, obtuse, mucronulate, 2-10 mm. long, about 1 mm. broad, glabrous or roughened with callous teeth; petioles 5-60 mm. long, sheathing at the base; cauline leaves like the basal, but the petioles entirely sheathing; peduncles axillary and terminal, 1.5-4 cm. long; involucre wanting, or of a solitary foliaceous bract; involucel of several linear bractlets, longer than the pedicels; rays 3-10, unequal, 0.5-2.5 mm. long; pedicels 3-12, 1-11 mm. long; fruit oblongovoid, 3-5 mm. long, about 3 mm. broad, more or less roughened with callous teeth, the ribs rounded, the lateral ribs with corky appendages; oil-tubes solitary in the intervals, 2 on the commissure; seed-face slightly concave. Type locality: "Llano Estacado, and headwaters of the Colorado," Texas, Pope Expedition . Distribution: Oklahoma to Texas and Nuevo Le6n (Bush 900, Earle &■ Tracy 402, Palmer