Botany Photo of the Day

A thank you to Jon of SMA@Flickr for today's photograph (original image | Flickr BPotD Group Pool). The SMA in Jon's Flickr ID stands for San Miguel de Allende, a historic town in Guanajuato, Mexico – a place which has been very much on my mind lately. I've bookmarked Jon's weblog, San Miguel Photos.

In his notes accompanying the photograph, Jon wrote that the common name for this plant in Mexico is romero cedro. After much searching, I did track down a reference for the name, the Flora Del Bajío Y De Regiones Adyacentes - Rosaceae, or the Flora of Bajío and Adjacent Regions - Rosaceae (Bajío is a region of plains in northern central Mexico). The common name of romero cedro actually applies to two species: Purshia plicata and Purshia mexicana (and presumably the hybrid between the two). Despite my limited ability to translate Spanish, it is quite evident this is Purshia mexicana, as it has white to yellowish flowers (instead of pink) and deeply-lobed leaves. There is a beautiful pencilled rendition of the flowers on a branch on page 115 of the flora, if you are patient enough for the file to load.

The English common name for this plant is Mexican cliffrose (or antelope bush). Following current taxonomy, it is native from Arizona to northern central Mexico, occupying the southern portion of this genus' distribution. A closely related species, Purshia stansburiana is sometimes classified as a subspecies of Purshia mexicana. If that treatment is followed, the range of Purshia mexicana extends as far north as Idaho. A different species, Purshia tridentata, reaches the northern limits for Purshia in the southern interior of British Columbia – expect a photograph of this species in late May after I attend Botany BC 2007 in Osoyoos. I find Purshia to be very photographically appealing due to its architecture.