Plants from Brazilian campos rupestres usually present morphological strategies that allow them to survive in extreme environments. However, in Chamaecrista (Leguminosae, Caesalpinioideae), one of the most diverse genera in the campos rupestres, needle-like leaflets are rare. Reviewing the species that present such leaf morphology, we describe Chamaecrista acicularis, a new species, from the Canastra Range, in the southwestern region of the state of Minas Gerais, Brazil. Phylogenetic analyses revealed that C. acicularis is not closely related to other quite similar needle-like leafleted species and that this trait evolved convergently. We also present comments on the phylogenetic relationships of needle-like leafleted species as well as the evolution of the leaflet amplitude, and a detailed description of C. acicularis alongside illustrations, photos, geographical distribution, a key to the needle-like leafleted species and taxonomic notes on similar species. Additionally, we expand the description of Chamaecrista strictifolia and present a conservation status for all needle-like leafleted species.

Table of leaf characters

Supplemental Table S1. Main leaf characters for all species used in ancestral character reconstruction and in our discussion.Table in DOCX file.

Table_S1.docx

Phylogenetic trees of Maximum Parsimony (MP) and Bayesian Inference (BI) analysis from ITS data set

Supplemental Data S2. Bayesian phylogenetic consensus tree (Newick format) resulting from ITS DNA sequences for 71 Chamaecrista sequences.

ITS_BI.tre

Supplemental Data S3. Maximum parsimony phylogenetic majority-rule consensus tree (Newick format) resulting from ITS DNA sequences for 71 Chamaecrista sequences.

ITS_MP.tre

Phylogenetic trees of Maximum Parsimony (MP) and Bayesian Inference (BI) analysis from ETS data set

Supplemental Data S4. Bayesian phylogenetic consensus tree (Newick format) resulting from ETS DNA sequences for 43 Chamaecrista sequences.

ETS_BI.tre

Supplemental Data S5. Maximum parsimony phylogenetic majority-rule consensus tree (Newick forma resulting from ETS DNA sequences for 43 Chamaecrista sequences.

ETS_MP.tre

Phylogenetic trees of Maximum Parsimony (MP) and Bayesian Inference (BI) analysis from trnL-F data set

Supplemental Data S6. Bayesian phylogenetic consensus tree (Newick format) resulting from trnL-F DNA sequences for 71 Chamaecrista sequences.

trnLF_BI.tre

Supplemental Data S7. Maximum parsimony phylogenetic majority-rule consensus tree (Newick format) resulting from trnL-F DNA sequences for 71 Chamaecrista sequences.

trnLF_MP.tre

Phylogenetic trees of Maximum Parsimony (MP) and Bayesian Inference (BI) analysis from nuclear combined data set

Supplemental Data S8. Bayesian phylogenetic consensus tree (Newick format) resulting from nuclear combined data set (ITS/5.8S+ETS) for 71 Chamaecrista sequences.

nuclear_BI.tre

Supplemental Data S9. Maximum parsimony phylogenetic majority-rule consensus tree (Newick format) resulting from nuclear combined data set (ITS/5.8S+ETS) for 71 Chamaecrista sequences.

nuclear_MP.tre

Phylogenetic trees of Maximum Parsimony (MP) and Bayesian Inference (BI) analysis from combined (all data) data set

Supplemental Data S10. Bayesian phylogenetic consensus tree (Newick format) resulting from combined (all data) data set for 71 Chamaecrista sequences.

combined_BI.tre

Supplemental Data S11. Maximum parsimony phylogenetic majority-rule consensus tree (Newick format) resulting from combined (all data) data set for 71 Chamaecrista sequences

combined_MP.tre

Tree with ancestral character reconstruction analysis

Supplemental Data S12.This tree file contains the character matrix, the set of 1,000 trees, which correspond to the last 500 trees from each of the two MCMC runs of the Bayesian combined analysis, and the majority-rule consensus tree of the Bayesian combined analysis. Data file for Mesquite (newick format).

reconstruction.tre