Eight species in the current treatment
POWO accepts Peniocereus greggii, P. johnstonii, P. lazaro-cardenasii, P. marianus, P. papillosus, P. striatus, P. viperinus and P. zopilotensis. This circumscription is narrower than that found in some older literature. Finding studies therefore requires checking the current name of each plant discussed. The names Cullmannia and Neoevansia are treated as generic synonyms of Peniocereus in this database. [2-WWW]
Underground organs and stem support
Studies of Peniocereus greggii and P. striatus describe plants with slender, brittle stems, frequently supported by shrub branches. Much of their biomass is below ground. The former develops a large tuberous root, whereas the latter has a more diffuse system of swellings. A similar aboveground appearance is therefore associated with different arrangements of storage organs. [Raguso et al. 2003] [Suzán et al. 1994]
Brief nocturnal flowering
In the Sonoran Peniocereus studied, flowers open in concentrated episodes. Long floral tubes and the arrangement of anthers and stigma permit pollination by hawk moths. Scent analysis also distinguished fragrant P. greggii flowers from a limited P. striatus sample in which floral volatiles were not detected. These findings describe the biology of the studied species rather than a uniform profile shared by all eight members of the genus. [Raguso et al. 2003]
Synonyms and names in the literature
Cullmannia · Neoevansia [2-WWW]