6) Draba, Arabis, Physaria, and other Brassicaceae

Starting to bloom today...

Here is some info on its natural range:
http://plants.usda.gov/java/profile?symbol=LEAR4

The first Draba is open in the alpine house at work...D. polytricha...the seeds came from Panayoti!

March 22 and this one is just starting to bloom in the alpine house at our Botanical Garden..another new early record. It will certainly be long gone before we open to the public for the season on May 1! Lovely fragrance on this one.

Only named in 1981, Physaria alpina is the queen of Colorado physarias. This shows it in a garden setting where it can last three or four years. The flowers are a really lovely deep yellow-orange, and the seed pods decorative. I think there is an alpine species in the Pacific Northwest...otherwise these are mostly plants of desert/steppe and montane screes.

Lesquerella ovalifolia, aka Lesquerella engelmannii var. ovalifolia is a highly localized endemic on the calcareous shales along the Arkansas river in the vicinity of Canyon City and Pueblo in southern Colorado. A trough featuring the many choice plants found in this area was created almost ten years ago as part of the trough exhibit at Denver Botanic Gardens.

What a horrible name for a plant! Physaria bellii is found only in a narrow band of shale along the base of the Front Range just west of Denver northward to the Wyoming border--roughly a hundred miles. Although occasionally impacted by development, I suspect this has probably increased its range thanks to people disturbing more ground.

There are several pictures of a trough in the Wildflowers Treasures trough plaza featuring the Niobrara shale area near Boulder where it's most abundant: you can see that it's almost more decorative in seed than in flower...

Who doesn't love D. polytricha, and the fussier D. mollissima and D. longisiliqua? I actually have grown these pretty well for a few years in this or that perfect little microclimate. But Draba rigida pays rent. This makes as dense and hard a cushion as any Dionysia, and seems to grow with impugnity in almost any microclimate in a classic rock garden: I have it on slopes facing every direction, in crevices, in hot spots and in quite deep shade.