General: Cactus Family (Cactaceae). Saguraro cactus have an erect, branched stem 3-16 m tall and 30-75 cm in diameter. The arms sometimes number as many as 50.
The ribs are prominent and number from 12 to 30. Gray spines densely cover the stem. The funnel form-campanulate flowers are 8.5-12.5 cm and the outer parts are green with lighter borders and the inner parts are petal-like and white. The nocturnal flowers appear singly at the uppermost areoles and they smell like ripe melons. When open, each flower is filled with many white stamens. The fruit is scaly, 25-45 mm in diameter and obovoid with a dark red interior and black seeds that are about 0.75 in diameter.
Distribution of Saguaro Cactus
This cactus is found on gravelly slopes, rocky ridges and outwash fans below 1500 m in the Lower Sonoran Zone, from northern Arizona and along the Colorado River in Riverside and Imperial Counties, California, to northern Sonora, Mexico.
Establishment of Saguaro Cactus
Saguaro cacti need well-drained soil and full sunlight for optimal development. They also cannot withstand prolonged temperatures below freezing. Since saguaros grow so slowly, it is best to obtain nursery-grown plants. Plant saguaros in the ground in October, being sure that the area selected is sheltered from full sun with a shade cloth or by other means through the first summer. Plants should be planted away from compacted areas that receive foot travel or heavy equipment. Young plants can be watered once a month during extended drought, but established plants can survive solely upon natural rainfall.
Ethnobotanic: The fruits and the seeds of the saguaro were extensively utilized for food by the Papago, Akimel and Tohono O'odham (also known as Pima), and Seri of Arizona and Mexico. In fact, families established camps in specific cactus areas and in both the Papago and Pima calendars, the saguaro harvest marked the beginning of the new year. The fruits were harvested with a special pole, often made of saguaro ribs with a small crosspiece. Some families still harvest the fruits today. A gruel was traditionally made from the saguaro fruits and used as a medicine by the Pima to make a mother's milk flow after childbirth. The seeds were roasted and ground on a metate and made into a mush. Other parts of the saguaro also were useful. The dead saguaro ribs were used by the Pima as splints to bind injured limbs and as cross pieces in the manufacture of babies' cradles. The Seri in Mexico used a piece of the saguaro rib to make the mainshaft or handle of a compound drill stick used in fire making. The ribs also were used as walking canes and in the making of wattle and daub house walls.
Wildlife: The white-wing dove feeds on saguaro seeds during the fruiting season. Gila woodpeckers and gilded flickers make holes in the trunks and use them as nests. After these are abandoned, they are inhabited by elf owls and starlings.