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Issue: Vol. 773 No. 3: 9 Sept. 2026
Type: Article
Published: 2026-09-09
DOI: 10.11646/phytotaxa.773.3.6
Page range: 281-288
Abstract views: 32
PDF downloaded: 3

A newly discovered species of Actinostemon (Euphorbiaceae) critically threatened from the Coastal Atlantic Forest of São Paulo State, Brazil

Centro Universitário Módulo; Curso de Ciências Biológicas; Rua Maria D’Assumpção Carvalho; 1000; CEP: 11662-047; Caraguatatuba; São Paulo; Brazil
University of Mississippi; National Center for Natural Products Research; School of Pharmacy; Oxford; MS; United States of America
Universidade Estadual do Ceará; Faculdade de Educação de Itapipoca; 62.500-000; Itapipoca; Ceará; Brazil
euphorbiaceae hippomaneae serra do mar taxonomy Eudicots Caraguatatuba plant taxonomy threatened species

Abstract

A new species of Actinostemon (Euphorbiaceae), restricted to a small area in São Paulo state, Brazil and critically threatened, is described here. The new species, Actinostemon caraguatatubensis is similar to A. concolor, with which it is compared. The new species is a small shrub, representing one of the smallest species of the genus, in addition to presenting the largest leaves ever documented in the genus. Two other characteristics, described here for the first time in the genus, is the presence of auriculate-based leaves and stipules. The new species grows in the understory of Dense Submontane and Lowland areas of the Atlantic Forest, typically near watercourses. Description, diagnosis, distribution map, comparisons with similar species, photographic plates, and preliminary conservation assessment are provided.

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How to Cite

Miranda, M.D., Külkamp, J. & Oliveira, L.D.S.D.D. (2026) A newly discovered species of Actinostemon (Euphorbiaceae) critically threatened from the Coastal Atlantic Forest of São Paulo State, Brazil. Phytotaxa 773 (3): 281–288. https://doi.org/10.11646/phytotaxa.773.3.6