I haven't had time to post (dig out) photos to the wiki. Peniocereus greggii ssp transmontanus is native throughout low-desert Arizona. There is probably no real difference between P. g. t. and the type. The tubers are edible and were sought for this. These and Wilcoxia / Echinocereus are very hard to find in the wild because they grow under desert shrubs and mimic their stems. P. g. has wonderful large fragrant flowers between April and June. All the plants in a given area will flower over the course of 1-3 nights. Fruits are large and bright red when ripe. The tuber grows very large with time. Historical records indicate tubers larger than many hundreds of pounds. It is easy to grow in a pot. It is best to use a mix without organic matter so repotting is not needed until the plant breaks the pot. Plentiful summer water is best so the plant remains in active growth. Plants need no winter water if they are cool. Plants will not tolerate much Arizona sun; they are understory plants. However, people in more northerly areas find full sun is fine. Tops are killed in heavy frosts, but tubers are quite hardy in the ground in dry soil (not in pots.) Cultivated seedlings can have tubers the size of golf balls by the end of their second summer. Stem cuttings can be rooted during warm weather, and form typical tubers. I am convinced this plant's reputation as hard to grow is due to unrecognized root mealy bugs. Wilcoxia are equally easy to grow, but their tubers resemble those of Dahlia. Cuttings also form tubers. Wilcoxia will flower throughout the summer once large enough; Peniocereus flower once per year, rarely twice. Either genus may carry dozens of flowers on a mature plant. There are quite a few Peniocereus native to Mexico and south. All are rewarding. My favorite sources for cactus seed are Mesa Garden in Belen, New Mexico, and the seed bank of the Cactus and Succulent Society of America. Leo Martin Zone ? Phoenix Arizona USA