Wright's Eryngo

Eryngium heterophyllum Engelm. in Wisliz. Tour Northern Mex. 106. 1848.
? Eryngium Haenkei Presl; DC. Prodr. 4: 94. 1830.
Eryngium Wrighlii A. Gray, PI. Wright. 1: 78. 1852.
Eryngium medium Hemsl. in Hook. Ic. pi. 2767. 1903.
Eryngium Altamiranoi Hemsl. & Rose; Rose, Contr. U. S. Nat. Herb. 10: 129. 1906.
Eryngium confusum Hemsl. & Rose; Rose, Contr. U. S. Nat. Herb. 10: 129. 1906.
Eryngium Endlichii H. Wolff, Repert. Sp. Nov. 8: 306. 1910.
Rather stout, caulescent, glabrous perennials, 2-6 dm. high, from a stout taproot, the stems erect, branching; basal leaves rosulate, narrowly oblanceolate to oblong-oval, 4—12 cm. long, 1-3 cm. broad, cuneate at the base, acute or obtuse at the apex, those of the sterile rosettes setose-dentate, the fertile spinose-serrate to pinnatifid or bipinnatisect, the teeth or lobes acute, pungent, callous-margined, the venation pinnately reticulate; petioles narrowly winged, sheathing at the base, 1-5 cm. long, shorter than the blades; cauline leaves numerous, like the basal, the lower pinnatifid or bipinnatisect, the upper opposite, sessile and palmately parted; inflorescence paniculately branched, the heads rather small, numerous, pedunculate, the flowers numerous; heads ovoid, blue to white, 7-15 mm. long, 5-10 mm. broad; bracts 8-14, rigid, spreading-ascending, linear-lanceolate to lanceolate, 12-25 mm. long, 2-5 mm. broad, pungent or acuminate, with 1 or 2 pairs of spinose teeth or entire, green or bluish beneath and yellowish-white above, exceeding or occasionally shorter than the heads; bractlets subulate, 3-5 mm. long, entire, curved, exceeding the fruit; coma of 1-4 entire bractlets, 5-15 mm. long, or occasionally obsolete; sepals ovate, about 1 mm. long, obtuse or truncate, apiculate; petals oblanceolate to obovate, about 1 mm. long; styles slender, exceeding the sepals; fruit globose, 1.5-2.5 mm. in diameter, with flat scales below the sepals and on the upper angles, the faces papillate.
Type locality: In valleys about Cosihuiriachi, Chihuahua, Wislizenius 176. Distribution ^Louisana, Texas, and Arizona to San Luis Potosi and Oaxaca (Pringle 13 530 Schaffner 548).