The Genus Sisyrinchium (Iridaceae) in Sierra Madre Occidental, Mexico: A New Species, Richness and Distribution

Several taxonomic novelties of the genus Sisyrinchium have been presented recently, so for some specialists this reveals the need of more systematic studies on the genus to better understand its diversity. They have also pointed out some regions as those of more priority to be explored. One of these is northwestern Mexico, in which after a floristic inventory in a Natural Protected Area in Sierra Madre Occidental, a new species was discovered. It is here described and illustrated as Sisyrinchium jacquelineanum, and diagnosed against S. polycladum, the morphologically most similar species. It differs from this by the growth habit, position of root thickenings, absence of fibrous remnants of old leaves at the base of the stem, flower size, and in the shape and pubescence of the capsules. An identification key for the 16 species of Sisyrinchium present in the Sierra Madre Occidental and an analysis of their richness patterns throughout this province are also provided.