About Pilosocereus gaumeri (Britton & Rose) Backeb.
Pilosocereus gaumeri is a slender, branching cactus that grows up to approximately 2.4 meters (8 feet) tall. Its stems range in color from green to yellowish green and bear 8 to 13 ribs. Areoles measure around 5 millimeters (0.2 inches) across and carry up to 15 rigid spines. These spines can reach up to 5 centimeters (2.0 inches) in length, and are yellow to brown when newly grown. Flowering areoles develop dense tufts of silky hairs that grow up to 5 centimeters (2.0 inches) long, while non-flowering areoles have few or no silky hairs. The flowers themselves are 5 to 7 centimeters (2.0 to 2.8 inches) long, and occasionally reach up to 8 centimeters (3.1 inches) in length. The outer flower segments, called tepals, are reddish green, and the inner segments range from white to yellowish green. Each flower only opens for a single night. When ripe, the fruits of this cactus have purple pulp. This species is endemic to the Yucatán Peninsula of Mexico, specifically found in the states of Campeche and Yucatán. It is the only Pilosocereus species that occurs in this region. In its natural habitat, Pilosocereus gaumeri often grows alongside Opuntia inaperta, and its stems are used as nesting sites by wrens.
