Common Name(s): Organ Pipe Cactus, Pitaya Dulce

Synonym(s): Lemaireocereus thurberi

Family: Cactaceae

Native To: Southern Arizona and northwest Mexico

Native Habitat: Stony desert and rocky hillsides

Growth Habit: Tall, erect succulents, usually much branched

Flowering: May - June (night blooming)

Distinguishing Characteristics: The slow growing Organ pipe is a large cactus, up to 25 ft high and 8 in thick; it branches from the base of the plant (in tropical Mexico the cacti assume a different shape, up to 40-50 feet tall and with single or few trunks, up to 2 feet wide). Its gray-green stems have 12-19 ribs that run the length of the stem. Areoles are set close together with 14-19 brown-black spines up to 1 ½ in, that turn gray with age. Flowers, up to 3 in long, are white in color and then produce 1 ½ inch wide red fruits that split when mature to reveal red flesh inside.

Natural History and Cultivation Notes: The name steno means "narrow", and cereus, a "torch-thistle", referring to the spiny and torch-shaped growth forms of these columnar cacti. This cactus is one of the largest in the US, after the Saguaro. Its peculiar shape loosely resembles the clustered pipes of a pipe organ, hence its common name. The flowers are white and open late at night. "The abundant nectar, nocturnal bloom, and musky odor suggest bat pollination. In an artificial setting, both honey-bees and bats pollinated the flowers. The nectar-feeding bats Choeronycteris mexicana and Leptonycteris sanborni are likely important pollinators" (Turner et al. 1995). The Organ pipe is sensitive to cold, and is found in the USA only in Southwestern Arizona, around the Organ Pipe Cactus National Park, but a few isolated individuals have been discovered growing naturally elsewhere in the state, even north of Tucson. It is common in the Sonoran desert and tropical deciduous forests of Mexico.

Ethnobotany: Fruits may be eaten fresh, dried, or can be made into a juice. Tohono O'Odham have harvested the fruits for centuries. Extremely sweet and juicy, the fruits have a flavor that is likened to watermelon. They can be prepared in many ways to make jams, fruit leather, syrups, and wine, although it can also delicious when eaten fresh. The mashed seeds of the fruit also produce an oily paste that can be used similarly to butter. The Seri used the cortex and pith of the dry cactus, mixed with animal fat, to make a tar-like caulking compound often used on boats. Ribs from the organ pipe were used to make cooking utensils, torches, fuel, hunting shelters, and the framework of various forms of houses (Felger and Moser 1991). In Mexico the plant is called pitayo dulce, meaning "sweet cactus" in reference to the edible fruit.

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