A New Species of Loeseliastrum (Polemoniaceae) From Northern Arizona

Loeseliastrum franciscanum R. Crawford, a local endemic known from three populations in the eastern San Francisco volcanic field of Coconino County, northern Arizona is newly described and illustrated here. This species is similar to L. depressum (M. E. Jones ex A. Gray) J. M. Porter & L. A. Johnson, but is distinguished by its strongly bilabiate corolla, long exserted stamens, pinnatifid leaves, and mostly tridentate inflorescence bracts. A revised key to Loeseliastrum is presented.