Influence of environment on the leaf morpho-anatomy and histochemical of the ayahuasca leaf: Populations cultivated in extra-Amazonian regions
Acta Scientiarum Biological Sciences April 3, 2020 Ordilena Ferreira de Miranda, Saulo Eduardo Xavier Franco de Souza, Rodrigo José Milan et al. 10 citations
The leaves of Psychotria viridis, a plant native to the Amazon used traditionally and in religious contexts, show adaptations to local climate and management. Plants from three populations in southeastern Brazil share basic leaf structures—dorsiventral mesophyll, uniseriate epidermis with large vacuolated cells and druses, and terminal stipules—consistent with the genus. A new finding is the amphi-hypostomatic leaf pattern (stomata on both surfaces). Variation in domatia presence within a population suggests this trait is unreliable for taxonomic identification. Adaptations to drier, warmer climates include secretory ducts, reduced stomata density, and smaller leaf area. Histochemical tests detected alkaloids, polysaccharides, proteins, and phenolic compounds; starch was absent only in water-stressed plants. These morpho-anatomical and histochemical changes likely result from seasonal water deficit and strategies to maintain or attract mutualistic organisms.