Etymology -Derived from the Greek penion, thread -which refers to the filaments in the flowers.
Plants in the genus Peniocereus are mostly sprawling stick-like plants from the Southwest United States and Mexico. In the wild, the plants are hardly noticed as they grow among shrubs and themselves appear to be simply dead branches. A number of the species feature large underground tubers which may reach 70 pounds or more. The flowers, by contrast, are as showy and prominent as the stems are nondescript and obscure. White and nocturnal in most species, rarely red, the flowers feature long, slender floral tubes, with prominent areoles and spines or bristles - often fragrant. Fruits are typically large and juicy with black seeds in white or red pulp.
Interest in the genus is variably lacking beyond the novelty of seeing the flowering "dead sticks" in the desert. Only a small number appear in cultivation. Certainly, a serious monograph on the genus would likely result in a splitting into at least 3 separate genera.