We embarked a road trip today along some back country dirt roads in and around the town of Sonoita. At one point, we found ourselves at a dead end and proceeded down a U.S. Forest Service road. (Noticed an awesome boondocking spot off the beaten path!) I saw these shrubs growing abundantly along the dirt road and had to get out of the truck to get a photo. The fragrance of the blossoms permeated the air as I exited the vehicle. These shrubs are not growing in the grassland where we are camped. As I look around, I noticed a decided change in the soil structure here where they are growing. Instead of the usual red clay soil we’re used to seeing, this area’s soil was more prominently white and calcic in nature. I read where the Fernbush and Cliff Rose both prefer to grow in limestone-rich soils. Hence, the reason why these shrubs are so localized to this location in the foothills. An interesting and somewhat technical explanation regarding desert soils of Arizona can be found here. The reading is a bit dense but if you plod through it – very interesting!
I have altered my original identification of this shrub. It’s more likely to be a cliff rose. A friend with extensive knowledge of the Arizona flora mentioned that it was probably either Apache plume or cliff rose. The habit is more in line with cliff rose – the fruit once it appears will decide! These flowers are born very close to the stem while the Apache Plume flowers appear on longer stalks. Fernbush is also in the rose family but the guide I was using seems to be inaccurate in its description. Thanks Kate for forcing me to take a closer look!
In my research to get a proper identification, I read there is an endangered species of cliff rose called Purshia subintegra or Arizona Cliffrose. Apparently, it does not grow in the national forest here in southern Arizona but is found sparingly in the Tonto National Forest and the Coconino National Forest.