Orthophytum cristaliense. Only recently described. https://phytotaxa.mapress.com/pt/issue/view/phytotaxa.430.3

Growing with Podocarpus sp., Eremanthus, Pilosocereus, etc. Likely exposed to lots of fog. Lichen on everything. White quartzitic rock that weathers in "knobby" patterns. Incredible habitat.