Plants of Crocus, with their familiar bright early-spring flowers at ground level, may appear to be established in lawns and along roadsides near houses where, however, they are very possibly simply the result of attemps at "naturalizing" them. Specimens have been seen from Crawford and Houghton Cos. The species most prone to self-sowing in gardens, and thus perhaps most likely to escape is C. tommasinianus Herb., though escapes apparently derived from C. vernus (L.) Hill are known from Ontario, and the Crawford Co. collection is thought to be C. flavus Weston.
1. Perianth less than 1.5 cm long; styles filiform, unbranched; sepals and petals alike.
1. Perianth more than 1.6 cm long; styles expanded, club-shaped, or branching; sepals and petals strongly differentiated in common species.
2. Flowers radially symmetrical; tepals all separate, in shades of blue, purple, white, or yellow (orange in I. domestica); with thick rhizomes.
2. Flowers ± bilaterally symmetrical; tepals connate into a tube, orange to red; with corms.