1. Leaves all netted-veined, of various shape (basal petioled with broad subcordate blades, upper and midcauline nearly sessile and lobed); bracts more than half as long as the head; petals blue; escapes from cultivation.
1. Leaves all parallel-veined, simple and elongate (yucca-like); bracts subtending heads less than half their length; petals white; rare native species.
All species found in Eryngium
MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. August 17, 2017. http://michiganflora.net/genus.aspx?id=Eryngium.