[Botany • 2017] A Nomenclator of Croton (Euphorbiaceae) in Madagascar, the Comoros Archipelago, and the Mascarene Islands

Diversity of flowers in coppery-lepidote tree species of Croton from Madagascar that are vegetatively very similar.

A Croton argyrodaphne, with leaves that are similar to those of several other species B Part of an inflorescence of Croton nobilis showing pistillate flower (below) with thick, reduplicate sepals and no petals, and staminate flower (above) with an intermediate number of stamens (ca. 18) C Staminate flower of C. chrysodaphne, with numerous (ca. 40) stamens and the unusual feature of ten (vs. normally five) petals D Pistillate flower of C. chrysodaphne, with patent, slender bifurcating styles and no petals E Staminate flowers of C. argyrodaphne, with only 11 stamens F Pistillate flower of C. argyrodaphne, with a stylar column topped by tightly bunched, short stigmas and also with recurved petals between the sepals (typically the pistillate flowers of this species are apetalous) G Base of an inflorescence of C. multicostatus showing three open pistillate flowers at the base (with well-developed, ligulate petals) and several open staminate flowers showing a low stamen number of 10 or 11.

Berry, Kainulainen & van Ee, 2017  

 Photos by P. Berry. DOI: 10.3897/phytokeys.90.20586 

Abstract

All published names of Croton from Madagascar, the Comoros, and the Mascarenes are treated here. We indicate which names are currently accepted (123 native species and 1 introduced), which ones we consider to be heterotypic synonyms (188), which ones are doubtful (25), and which ones should be excluded (5). We newly designate lectotypes for 108 names, and epitypes for C. anisatus Baill., C. nobilis Baill., and C. submetallicus Baill. A total of 133 names are newly treated as synonyms. One new combination is made, Croton basaltorum (Leandri) P.E.Berry for C. antanosiensis var. basaltorum Leandri, and one new name is proposed, Croton toliarensis B.W.vanEe & Kainul. for C. tranomarensis var. rosmarinifolius Radcl.-Sm.

Keywords: Euphorbiaceae, Croton, Madagascar, Comoros, Mascarenes, nomenclator, synonymy

Figure 1. Diversity of flowers in coppery-lepidote tree species of Croton from Madagascar that are vegetatively very similar.
A Croton argyrodaphne, with leaves that are similar to those of several other species B Part of an inflorescence of Croton nobilis showing pistillate flower (below) with thick, reduplicate sepals and no petals, and staminate flower (above) with an intermediate number of stamens (ca. 18) C Staminate flower of C. chrysodaphne, with numerous (ca. 40) stamens and the unusual feature of ten (vs. normally five) petals D Pistillate flower of C. chrysodaphne, with patent, slender bifurcating styles and no petals E Staminate flowers of C. argyrodaphne, with only 11 stamens F Pistillate flower of C. argyrodaphne, with a stylar column topped by tightly bunched, short stigmas and also with recurved petals between the sepals (typically the pistillate flowers of this species are apetalous) G Base of an inflorescence of C. multicostatus showing three open pistillate flowers at the base (with well-developed, ligulate petals) and several open staminate flowers showing a low stamen number of 10 or 11. Photos by P. Berry.

 Paul E. Berry, Kent Kainulainen and Benjamin W. van Ee. 2017. A Nomenclator of Croton (Euphorbiaceae) in Madagascar, the Comoros Archipelago, and the Mascarene Islands. PhytoKeys. 90; 1-87.  DOI: 10.3897/phytokeys.90.20586