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 | | Davis' green pitaya is also found in very close association with several other species of dwarf cacti such as Coryphantha hesteri, C. minima, C. varicolor, C. echinus, Thelocactus bicolor, and Echinocereus spp. |
 | | Within the occupied sites, however, the ecological/edaphic factors affecting Davis' green pitaya seem clear: the Echinocereus is totally absent from the alluvial soil surrounding the occupied novaculite ridge and it is restricted to hills and ridges composed of highly erosion-resistant quartz (14). |
 | | Within these novaculite habitats, the species is absent from patches of loose, powdery, exposed soil and are present in areas having a very stable soil surface (consolidated by dense mats of Selaginella roots, both living and dead, and/or covered by small novaculite chips) (14). |
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