Thanks again to Dale from California aka Dfunk@Flickr for today's image of Yadon's wallflower from Monterey County in California. As before, Dale shared the image through the Botany Photo of the Day Flickr Group Pool (original image). Much appreciated, Dale.

Erysimum menziesii subsp. yadonii is endangered, so it is likely that this image is the closest that you and I will ever come to seeing the plant – it doesn't seem to be in cultivation. From what I've been able to discern, it is found in only one locale in the world (the coastal sand dunes near Marina, California). It has the dubious distinction of receiving California's highest designation for endangered organisms, S1.1. The .1 means “very threatened”, while S1 means “Less than 6 Element Occurrences (EO) OR less than 1000 individuals OR less than 2000 acres”. Lastly, an EO is defined as “an area of land and/or water in which a species or natural community is, or was, present”.

The name of the plant honours two botanists, Archibald Menzies (1754-1842) and Vern Yadon. Yadon is a resident of the area and former director of the Pacific Grove Museum of Natural History.

Photography / nature resource link: the nature photography of Michael Brown – in particular, check out the flora gallery linked to from the bottom left of the page.