Being in the presence of Stanleya pinnata in bloom had been on my “list” for quite some time, so it was a joy to see it often on a May 2015 trip to the southwest USA.
Desert prince’s plume is the most common of the six or seven species in this genus restricted to western North America. Stanleya is named in honour of Edward Smith Stanley, an English politician and naturalist.
The Flora of North America account for Stanleya pinnata notes the species as being a “perennial, subshrub or shrub”. The difference between each of these growth forms is where the perennating buds occur: below ground for the perennial, at ground level for the subshrub, or elevated above the ground level for the shrub. In harsher (colder) climates, one would expect populations of individual plants to lean more toward the perennial life-form. Conversely, in warmer climates, being a shrub is hypothetically more likely. Of course, I could be wrong–one would need to do the research to confirm. Where conditions are right, plants of desert prince’s plume can reach 1.5m (5 feet) in height. Again, I suspect this would be where plants are shrubs, as they would have a headstart on achieving height each growing season.
Nature / literature resources: For a time, Edward Smith Stanley was patron of the sometimes-nonsensical Edward Lear. A new book has been written about The Natural History of Edward Lear. If that’s too time-intensive, you could instead read this article on Edward Lear’s Nonsense Botany via American Scientist, or, quicker yet, see some examples.