Croton serratifolius Baillon (1864: 312)

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 : 258

32. Croton serratifolius Baillon (1864: 312) .

Lectotype (designated here): — BRAZIL. Rio Grande do Sul: 1821, A. Saint-Hilaire C2 2704 ( P 00493375 !; isolectotypes A 00047422, F 0093310!, P 00493376!) . ( Fig. 17 , F–J)

This shrub can be recognized by its stipules, bracts, and glandular pistillate sepals with stipitate glands (colleters) along the margin. In the field, these glands are greenish and give the plant a viscous appearance; plants are frequently visited by ants. Despite the species epithet being “ serratifolius ”, we have seen entire and serrate leaf margins in the same individuals. The species morphologically resembles Croton chaetophorus , but both species can be differentiated by vegetative characteristics (see comments in C. chaetophorus ).

Caruzo et al. (2020) recognized C. garckeanus Baillon (1964: 308) as a synonym of C. serratifolius , and we agree with that. Nevertheless, Croton garckeanus requires further evaluation and the study of more collections to identified additional characters that help to support this claim. The species is a member of section Barhamia subsect. Medea .

Distribution and habitat:— It occurs in Argentina, Paraguay and Brazil (MS, PR, RS, SC, SP) ( Caruzo et al. 2020), growing in open vegetation; often found in ‘cerrado’, between 555 and 1035 m elevation ( Fig. 16 ).

Phenology:— Flowering from October to April, and fruiting from October, January and March.

Representative specimens:— PARANÁ: Balsa Nova, Ponte dos Arcos, 06 July 2005, C . Kozera & O. P . Kozera 2239 ( MBM). Bituruna, Fazenda Lageado Grande, 17 September 2003, D. Liebsch 581 ( HFC, MBM). Campo Mourão , Cerrado Valtra, 24°00’’52.04’ S, 52°21’47.02” W, 555 m , 18 October 2016, A. P. N . Pereira, F. S . Petrongari & O. L. M . Silva 26 ( SP). Curitiba, Bariguy , 30 June 1958, R . Lange 1121 ( MBM). União da Vitória, Estrada para Porto Vitória , 16 October 1966, G . Hatschbach 14889 ( K, MBM, NY, P) .

Figures

FIGURE 16. Map showing the known geographic distributions of Croton salutaris, C. sanctae-crucis, C.serpyllifolius, and C. serratifolius in Paraná state.

FIGURE 17. Croton serpyllifolius. A. Habit. B. Staminate flower. C. Pistillate flower. D. Detail of twice bifid styles. E. Capsule. C. serratifolius. F. Young branch. G. Stipules with multiple glandular colleters. H. Inflorescence. I. Pistillate flower. J. Young capsule showing the stalked green colleters along the margins of the sepals. C. splendidus. K. Habit. L. Pistillate flower. M. Capsule. Photos: A.P.N. Pereira.