Croton bonplandianus Baillon (1864: 339)

Pereira, Amanda Da Paixão Noronha, Riina, Ricarda & Caruzo, Maria Beatriz Rossi, 2022, Croton (Euphorbiaceae) of the Brazilian state of Paraná: an annotated checklist, species distribution, and identification key, Phytotaxa 570 (3), pp. 231-274 : 237

3. Croton bonplandianus Baillon (1864: 339) .

Lectotype (designated by Berry et al. 2017):— ARGENTINA. Corrientes: 1833, A.J.A. Bonpland s.n. ( P 00623061 !; isolectotype P 00623060!) . Remaining syntypes:— PARAGUAY: April–May 1845, H.A. Weddell 3207 (P 00623062!, P 00623063!). ( Fig. 1 , J)

This species is a small shrub. Paraná specimens are unusually glabrescent, compare with specimens from Paraguay, Argentina and Bolivia, which are more similar to the type specimen, having a sparse indument of whitish trichomes on branches, leaves, and fruits. Croton bonplandianus is also characterized by its delicate lax inflorescences, the presence of a pair of sessile or subsessile patelliform basilaminar nectary glands, and oblongoid capsules. Specimens of Croton bonplandianus from Paraná have been identified erroneously in herbaria as C. glyptospermus Müller Argoviensis (1873: 117) , a species described for Goiás state. These species can be distinguished by leaf shape (ovate-lanceolate to lanceolate in C. bonplandianus vs. ovate to broadly ovate in C. glyptospermus ), leaf margin (serrulate in C. bonplandianus vs. entire in C. glyptospermus ), indument on the abaxial side of leaves (sparsely pubescent to glabrous in C. bonplandianus vs. densely pubescent in C. glyptospermus ), and fruit shape (oblongoid in C. bonplandianus vs. globose in C. glyptospermus ). It belongs to sect. Adenophylli subsect. Pungentes Croizat (1944: 19) ( van Ee & Berry 2021).

Distribution and habitat:— It occurs in Argentina, Bolivia, Paraguay, Uruguay and Brazil (MS, MT, PR) ( Caruzo et al. 2020). The native range of Croton bonplandianus is in the Neotropics, however, it is an introduced and naturalizing species in tropical Africa, Asia, and in the Western Indian Ocean Region ( Berry et al. 2017, WCSP 2022). Shrubs growing near to the Paraná river, in dry environments, and, rarely in edges of semideciduous seasonal forest, between 230 and 300 m elevation ( Fig. 2 ).

Phenology:— Flowering and fruiting from October, September and November.

Representative specimens:— PARANÁ: Diamante do Norte , Estação Ecológica do Caiuá, 10 November 2001, C. I. L. F . Rosa 68 ( HUEM). Idem, idem, 06 September 1998, J. M . Silva , E . Barbosa & L. O . Abe 2491 ( MBM). Marilena, Rio Paranapanema, 14 March 2007, M. C . Souza , J . D. Dias , S . Rodrigues , T. S . Michelan & V. C . Harthman 1695 ( HUEM). Porto Rico, Ilha Porto Rico, Lagoa Figueira, 27 March 2008, K. K . Kita , L. F . Viana , Z . Marchetti & I . Galbiati 735 ( HUEM). São Pedro do Paraná , Porto Eucalipto, rio Paraná margem esquerda, 05 December 2006, M. C . Souza , S. R . Slusarski , S . Rodrigues & A. S . da Silva 1742 ( HUEM) .

Figures

FIGURE 1. Croton aberrans. A. Inflorescence. B. Staminate flowers. C. Pistillate flowers. C. antisyphiliticus. D. Habit. E. Stipules. F. Leaf margin, arrows point to nectary glands in the sinuses. G. Inflorescence showing pistillate flowers at the base. H. Staminate flowers. I. Pistillate flowers. C. bonplandianus. J. Inflorescence. Photos: A–I: A.P.N. Pereira. J: O.L.M. Silva.

FIGURE 2. Map showing the known geographic distributions of Croton aberrans, C. antisyphiliticus, C. bonplandianus, and C. calycireduplicatus in Paraná state.