This wildflower is Asclepias asperula, with a common name Antelope Horns. A strange yet beautiful plant that is growing wild all over our land. It was by lucky chance that Dripping Springs Babble featured a photo of it as a pic of the week identifying it as a milkweed. I then googled "milkweed" and was surprised to learn that there are many many varieties. This variety is prevalent in the Southwest and it primarily serves as a source of nectar for bees and larval for butterflies.
Photo Taken by Wing-Chi Poon on 23rd April 2005 at Gorman Creek Trail, Colorado Bend State Park, Bend, Texas, USA. Category:Asclepias asperula