Growth form and scope of the name
The stems are thin and brittle, and growth among shrub branches provides support. The substantial storage organ lies below ground. POWO recognizes Peniocereus greggii subsp. greggii and P. greggii subsp. transmontanus. The flower study published by Raguso and colleagues examined material identified as variety transmontanus, now treated at subspecies rank. The germination experiment with Chihuahua seeds does not provide an infraspecific identification. [2-WWW] [Raguso et al. 2003] [Loweree-Rivera et al. 2026a]
Flowers and fragrance
In populations observed near Tucson, Peniocereus greggii flowered synchronously on relatively few nights during a season. Flowers opened at dusk, and nectar-feeding hawk moths contacted their reproductive structures. Bagged flowers pollinated with their own pollen aborted developing fruits. Eight benzenoid compounds were identified in the floral fragrance, characterizing the chemical signal accompanying nocturnal flowering. [Raguso et al. 2003]
Seeds from two collection years
An experiment conducted in 2023 compared seed lots collected in 2016 and 2022 at San Onofre, Chihuahua. The older lot germinated more successfully, and the moderate regime around 24°C was more favourable than the hotter regime tested. Sulfuric acid treatment or an incision in the seed coat did not improve germination. The after-ripening interpretation must account for the absence of initial viability measurements and the separate collection histories of the two lots. The result concerns these seeds and procedures. [Loweree-Rivera et al. 2026a]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Cactáceas y Suculentas Mexicanas 1959]
Synonyms and names in the literature
Cereus greggii [2-WWW]