Eryngium fluitans M. E. Jones

Eryngium fluitans M. E. Jones, Contr. W. Bot. 12: 42. 1908
Eryngium mexicanum sensu H. Wolff in Engler, Pflanzenreich 61 (4 22s ) : 178. 1913. Not E. mexi-
canum S. Wats. 1891. Eryngium Wolffii Mathias, Ann. Mo. Bot. Gard. 16: 395. 1929.
Slender, caulescent, glabrous, perennials (?), 1.5-4 dm. high, from a fascicle of fleshyfibrous roots, the stems several, weakly erect or ascending, branching; basal leaves linear to lanceolate, 2-15 cm. long, 0.5-3 cm. broad, entire or ternate to pinnatisect, the linear or lanceolate lobes entire or obsoletely serrate, 1-2 cm. long, the venation pinnately reticulate; petioles fistulose, septate, broadly sheathing at the base, 0.5-1 dm. long, exceeding the blades; cauline leaves like the basal, entire to ternately or pinnately parted with herbaceous, weak, and often elongate divisions, the upper leaves sessile and opposite; inflorescence successively trifurcate or cymose, the heads rather large, numerous, pedunculate, the flowers numerous; heads blue, ovoid-cylindric, 10-15 mm. long, 6-S mm. broad; bracts S— 12, rigid, spreading, linear-lanceolate to lanceolate, 10-15 mm. long, pungent, entire or with a pair of obsolete spines, green beneath and yellowish-white above, shorter than or exceeding the heads; bractlets subulate, 2-3 mm. long, entire, exceeding the fruit; coma of a single entire or shallowly lobed filiform bractlet, 15-25 mm. long; sepals ovate, about 0.5 mm. long, obtuse, apiculate; petals spatulate, about 0.6-0.8 mm. long; styles slender, exceeding the sepals; fruit ovoid, 1-2 mm. long, densely' covered with subequal, white, lanceolate scales.
Type locality: Marsh Lake, Sierra Madre, Chihuahua, M. E. Jones. Distribution: Chihuahua to Mexico (Pennell 18,288, Pringle 3180).

Eryngium fluitans là một loài thực vật có hoa trong họ Hoa tán. Loài này được M.E.Jones mô tả khoa học đầu tiên năm 1908.