Survivors in the desert

Saturday
Today, we visited the eastern section of Saguaro National Park, the Rincon Mountain District. There is an 8-mile scenic loop in the west of this area, but much of the area can only be explored on foot or on horseback. We did several trails, the longest being a little over 6 miles, then a fairly short and informative nature trail, and finally in the late afternoon, another 3-mile one. For my collage I chose three striking cacti we saw today. The first is a Crested or Cristate Saguaro cactus, in which the cells in the growing stem begin to divide outward, rather than in the circular pattern of a normal cactus. This is an unusual mutation which results in the growth of a large fan-shaped crest at the growing tip of a saguaro’s main stem or arms. The cause for this mutation is unknown; though there has been some speculation about the presence of a “trigger,” such as frost for example, which may initiate the process. Top right is a fish hook barrel cactus, coming into bud. The fishhook barrel cactus typically grows to a diameter of roughly 2.25 ft and a height of 3–6 ft. The name comes from the spines, which are thick and hooked. Its flowers are yellow to red-orange and appear atop the cactus fruit during the summer months. In adulthood, fishhook barrel cacti generally lean southward, toward the sun, earning them the nickname "compass barrel cactus." One theory as to the cause of this is that the afternoon sun is so intense it slows the growth on the exposed side, causing the plant to grow unevenly. Older barrels can lean so far they uproot themselves and fall over, especially after heavy rains, and we came across several examples where this had happened. Lower right is the not so cuddly Teddy bear cholla, so called because in certain light, its dense yellow spines (which are barbed) appear gold and fuzzy. The teddy bear cholla has a single trunk, three to five feet high, with densely-packed side branches on the upper part of the plant.

Step count for today: 25,816