31. Croton serpyllifolius Baillon (1864: 355) .

Lectotype (first step designated by Lima & Pirani 2008b, second step designated here): — BRAZIL. São Paulo: “près d’un ruisseau, dans le voisinage d’Eyneja-Villa”, s.d., A. Saint-Hilaire cat. C2 1495 (P 00634713!; isolectotypes P 00634714!, SP 000664!, F 0092877!) . Remaining syntype: — BRAZIL. “bords du chemin près de Rincao da Cidade”, s. dat., A. Saint-Hilaire cat. C2 1580 (P 00634715!) (Fig. 17, A–E).

Croton serpyllifolius is a shrub that can be confused with C. chamaepitis and C. pycnocephalus (see Table 1). According to Lima & Pirani (2008b), the species is endemic to the state of São Paulo. However, Paraná specimens show morphological characters in agreement with the information of the protologue and type collections, corroborating the information from Caruzo & Cordeiro (2007), who recognized the occurrence of the species in Paraná. The species belongs to section Lamprocroton subsect. Argentini .

Distribution and habitat:— It occurs in south (PR, SC) and southern (SP) (Caruzo et al. 2020), where it grows in open vegetation (‘campo limpo’), between 800 and 1050 m elevation (Fig. 16).

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

Representative specimens:— PARANÁ: Balsa Nova, Ponte dos Arcos, 25°33’16”S, 49°48’11”W, 808 m, 18 December 2013, J. T . Motta, L. T . Dombrowski, J . Cordeiro & D. P . Saridakis 4204 (HCF, MBM, RB). Palmeira, Estrada Rodovia Palmeira-Ponta Grossa, 12 October 1959, G . Hatschbach 6482 (MBM). Ponta Grossa, Fazenda Barrozinho, 07 September 1967, G . Hatschbach 17093 (MBM). Tibagi, Taipa de Pedra, 19 October 1993, G . Hatschbach & J . Cordeiro 59670 (MBM). Idem, Parque Estadual do Guartelá, Rio Iapó, 02 September 1996, S. R . Ziller 1573 (ESA, MBM) .