Two Distinct Mimosas Distinguishing M. borealis from M. texana To create the flower images above individual flowers were separated from the flower clusters, pressed, placed on a scanner, and directly scanned at 1200 dpi for magnification. To view the flower scan sets.
Older prickles are triangular in shape, gradually flattening to the base, and only minimally curved.
Flower color is not a reliable distinguisher, but texana is generally much paler. Similarities in foliage between M. borealis and M. biuncifera were judged to be more likely due to parallelism than to introgression. Our discussion assumes the Barneby and Isely 1986 proposal to split M. biuncifera into two species, one of which is M. texana . Values from Isely 1998. None of our M. texana exhibit more than 3 pinnae.