Orthophytum zanonii grows on the drier slopes of the hill called Pedra do Vidal about 300 m elevation, which is covered by a deciduous forest. This bromelioid was observed during the drier season - indeed a very severe drought lasting for almost one year - when the trees lose all or nearly all of their leaves. It grows in slightly inclined rock outcrops inside the forest and in nearby open areas fully exposed to sun light, forming large and very dense terrestrial or saxicolous clumps with leaves varying in size and color (i.e., greenish, reddish or whitish) depending on the intensity of the exposure to sun light. It is interesting to observe that the specimens photographed three years earlier by Marcos Zanoni, during the rainy season, at the same place of collection, showed the upper leaves becoming more reddish around the inflorescence at anthesis, differently from the specimens we collected with concolorous leaves at anthesis. The very dense layer of white trichomes obscuring the leaf color in the dry season may explain why the feature portrayed by Dr. Zanoni was not observed during collection of the type —SeeJ. Bromeliad Soc.
