Eryngium petiolatum Hook.

Eryngium petiolatum Hook. Fl. Bor. Am. 1: 259. 1832
Eryngium petiolatum var. juncifolium A. Gray, Proc. Am. Acad. 8: 385. 1872.
Slender, caulescent, glabrous perennials, 2-5 dm. high, from a cluster of fibrous roots, the stems erect or ascending, branching; basal leaves lanceolate to oval, 2-7 cm. long, 0.5-1 cm. broad, acuminate at the apex, remotely to coarsely spinulose-serrate, the venation reticulate, or the blades obsolete; petioles slender, elongate, septate, 1-4 dm. long, greatly exceeding the blades; cauline leaves like the basal but short-petiolate or sessile, spinulose-serrate, reduced above; inflorescence cymose, the heads small, numerous, short-pedunculate, the flowers numerous; heads globose, 5-8 mm. in diameter; bracts 8-12, rigid, linear, 10-15 mm. long, subulate, obscurely callous-margined and spinose-ciliate with 4-6 spines, broadly dilated and scarious-margined at the base, about twice as long as the heads; bractlets like the bracts, 5-8 mm. long, with 2-5 spines, the dilated scarious base partially enfolding the flower and fruit, exceeding the fruit; coma wanting; sepals lanceolate, 3 mm. long, acuminate, entire or rarely few-toothed; petals obovate, 1.5 mm. long; styles a little shorter than the sepals; fruit oblongovoid, 2 mm. long, densely covered with depressed, flat, white, lanceolate-acuminate scales, 1-1.5 mm. long.
Type locality: Moist soils on the plains of the Multnomah [Willamette] River, Oregon, Douglas.
Distribution: Dried swales; western Oregon and contiguous Washington (Eastwood 2120,

Eryngium petiolatum là một loài thực vật có hoa trong họ Hoa tán. Loài này được Hook. mô tả khoa học đầu tiên năm 1832.