Tucson is ringed with mountains; many of these and the desert around them are all manner of city, state and national park land. We hope to explore them all and started today with the eastern part of Saguaro National Park, named after the cactus that we have come to expect in the scenery of the Old West and Mexican desert. Easterners be warned: Do not pronounce the "g" in saguaro or everyone will know you are from elsewhere.
The Saguaro is a plant with personality; the fanciful semi-human shapes get the imagination going. This huge plant thrives under conditions that few can bear. As long as there are two downpours a year, a large cactus can take in enough water (200 gallons) to last the rest of the year in 110+º. The accordion style pleats that cover its woody skeleton expand and contract depending on how much water is being stored inside. Desert birds often made holes in the saguaro and raise their young inside. The evaporating moisture from the cactus tissue evaporates and cools the nest in the excessive summer heat. The saguaro starts life from a seed and grows as little as 1/4 inch a year. After fifteen years it may barely be a foot tall. After thirty years saguaro begin to flower and produce fruit, reproducing themselves. By 50 years they can be seven feet tall, but they generally don's spout arms until 75 years have gone by. Those that live 150 years or more rise 50 feet over the desert and can weigh eight tons. The cactus here are at the northern edge of their range and are vulnerable to freezing temperatures and lightening. They have surprising shallow root systems and tip over easily during strong winds.
We drove a circle loop through the park and took a hike admiring the saguaros and their prickly neighbors. The Spanish gave the Palo Verde a most appropriate name - green stick. When the heat is excessive, this plant drops its leaves and smaller branches but the bright green coating on the trunk and main branches keeps photosynthesizing. The cholla is especially nasty. If you get near one the slightest wind will cause it to leap off and attach to you. If you use your hand or some implement to remove it, the cholla sticks to that instead. I am writing this from personal experience!