Eryngium hemsleyanum H. Wolff

Eryngium hemsleyanum H. Wolff in Engler, Pflanzenreich 61 (4 228 ): 255. 1913.
Slender, caulescent, glabrous perennials, 0.5-2 m. high, from a short oblique or horizontal tuberous rootstock bearing a fascicle of fleshy-fibrous roots, the stems solitary, erect, simple below; basal leaves numerous, linear-lanceolate, 15-35 (or 60) cm. long, 5-10 (or 15) mm. broad, broadest at the base or the middle and attenuate at the apex, densely spinose-lobed, the lobes stout, ascending or spreading, the longest 5-22 mm. long, axillary spines present, the venation parallel; sheaths usually as broad as the leaves, vaginate, 2-4 cm. long; cauline leaves few, the lower like the basal but clasping, alternate, little reduced, ascending, the uppermost reduced, opposite, all very spinose; inflorescence divaricately cymose, the heads numerous, rather large, pedunculate, the flowers numerous; heads ovoid, 8-15 mm. long, 7-12 mm. broad, more or less rounded at apex and base; bracts 6-S, rigid, spreading, lanceolate, 3-10 mm. long, pungent, entire or few-toothed, much shorter than the heads or occasionally longer; bractlets broadly lanceolate, 3-5 mm. long, pungent, entire, exceeding the fruit; coma wanting; sepals ovate, about 1.5 mm. long, obtuse, apiculate; petals oval, about 1.5 mm. long; styles slender, greatly exceeding the sepals; fruit turbinate, about 2 mm. long, the calycine and lateral scales flat, tawny, ovate-lanceolate, to 1 mm. long, the lateral forming incised wings, the dorsal reduced or obsolete.
Type locality: San Luis Potosi, Schaffner 547.
Distribution: Nuevo Le6n and Tamaulipas to Vera Cruz and Puebla (Pennell 17,118, Pringle 3698).