Organ Pipe Cactus The organ
pipe cactus grows only in the Sonoran Desert. It is
found from southwestern Arizona south to Sonora,
Sinaloa and Baja California in Mexico. Organ Pipe
National Monument in Arizona was created to protect
the cactus in its northern most range. Organ pipe
cacti are very sensitive to frost. Because cold air
settles in valleys and the desert floor, the heat
loving organ pipe cactus grows on southern facing
slopes below elevations of 3,000 feet. The organ
pipe cactus gets its name from the many slender,
curving vertical stems which resemble the large
pipes of an old-fashioned organ. Growing from a
base just above the ground, the column-like stems
can Like the saguaro, the organ pipe cactus needs shade and protection for a few years during its seedling stages. It depends on "nurse plant" like the desert ironwood, palo verde and triangle-leaf bursage to develop. When the organ pipe cactus matures, its root system will eventually absorb any rain that falls. This deprives the nurse plant of the water it needs, and as a result it becomes stunted or dies. The organ pipe cactus stores water in its stems to survive the heat and drought of the desert. It has fibrous ribs running vertically up the stem to help keep it upright. When the cactus dies it leaves behind its bleached ribs. The flower
buds of the organ pipe cactus grow from the tip of
the stems. The flowers are white or pale lavender
in color. They mostly bloom at night and are
pollinated by nectar feeding bats, and by morning
they close up again. The cactus has many buds which
open up on different days so that the flower season
can last for many weeks. They bloom annually from
May to July. The red
fruits are large and spiny, and ripen in late
summer. When they mature, they lose their spines
and open to show an edible, red pulp.
They Native Americans ate the fruit raw or dried it for storage. The wood of the ribs was used for building and turned into torches. The organ pipe cactus is not endangered in its range, although it is protected in the USA, where it grows only in a small section of southernwestern Arizona. 2002
bibliography: Organ Pipe", http://www.dbg.org/Involved/organpipe.html "ORGAN PIPE", http://helios.bto.ed.ac.uk/bto/desbiome/organpip.htm "organpipecactus.html", http://www.bio.gasou.edu/Bio- home/Courses/environmental/leege/BOO/ghseontheweb/desert/organpipe cactus.html "CACTI OF SOUTHERN CALIFORNIA", http://www.halice.com/tucson/cacti.html "Plants at Organ Pipe National Monument", http://data2.itc.nps.gov/nature/plants.cfm?alphacode=orpi&loc=2
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