Pterocereus gaumeri

References

1. [1]Desert Tropicals — http://www.desert-tropicals.com/ ↩︎The main focus of the site is succulent plants, but it also contains information on a wide range of other species. Usually at least one good photograph, plus basic information about the plant and its cultivation.
2. [2]The Cactus Family — Anderson E.F. · Timber Press; Portland, Oregon · 2001 · ISBN 0-88192-498-9 ↩︎An excellent work, giving botanical descriptions of virtually all the cacti, together with their range (but not their habitats) and sometimes also a photo. it also contains a long chapter detailing the many uses of cacti and another on cultivation..
3. [3]IUCN Red List of Threatened Species — http://www.iucnredlist.org/ ↩︎A list of plants under threat and facing possible extinction, usually with brief details of the threats and information on habitat.
4. [4]Flora of Yucatan — Standley P.C. · Field Museum of Natural History; Chicago · 1930 · http://www.biodiversitylibrary.org ↩︎The first flora that was attempted for this area in 1930, so it is obviously lacking information and the Botanical names can be out of date. Still, an excellent work and it records many plant uses. It can be downloaded from the Internet.