Croton (Euphorbiaceae) of the Brazilian state of Paraná: an annotated checklist, species distribution, and identification key Author Pereira, Amanda Da Paixão Noronha 0000-0003-4874-129X Instituto de Pesquisas Ambientais, Núcleo de Pesquisa Curadoria do Herbário, São Paulo, SP 01061 - 970, Brazil & Universidade Federal de São Paulo, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Departamento de Ecologia e Biologia Evolutiva, 09972 - 270, Diadema, SP, Brazil. & amanda. pnoronhap @ gmail. com; https: // orcid. org / 0000 - 0003 - 4874 - 129 X amanda.pnoronhap@gmail.com Author Riina, Ricarda 0000-0002-7423-899X Real Jardín Botánico (RJB), CSIC, Plaza de Murillo 2, 28014, Madrid, Spain. & rriina @ rjb. csic. es; https: // orcid. org / 0000 - 0002 - 7423 - 899 X rriina@rjb.csic.es Author Caruzo, Maria Beatriz Rossi 0000-0002-8393-214X Instituto de Pesquisas Ambientais, Núcleo de Pesquisa Curadoria do Herbário, São Paulo, SP 01061 - 970, Brazil & Universidade Federal de São Paulo, Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Departamento de Ecologia e Biologia Evolutiva, 09972 - 270, Diadema, SP, Brazil. & mbrcaruzo @ unifesp. br; https: // orcid. org / 0000 - 0002 - 8393 - 214 X mbrcaruzo@unifesp.br text Phytotaxa 2022 2022-10-28 570 3 231 274 http://dx.doi.org/10.11646/phytotaxa.570.3.1 journal article 176492 10.11646/phytotaxa.570.3.1 e5151877-6fa0-44de-b9c3-4577de526c95 1179-3163 7260277 27. Croton pycnocephalus Baillon (1864: 356) . Type: — BRAZIL . Rio Grande do Sul : 1864, C. Gaudichaud-Beaupré 1668 ( holotype P 06773116 !; isotype A 00257986!). ( Fig. 15 , C–D) This shrub can be distinguished by the indument of stipitate stellate trichomes distributed throughout the plant, small leaves (up to 1.5 cm long), and staminate petals that are twice the size of the sepals. Due to its small leaves and twice bifid styles, C. pycnocephalus is commonly confused with C. serpyllifolius and C. chamaepitis , however, several vegetative characteristics distinguish it from both species ( Table 1 ). The species belongs to section Lamprocroton subsect. Argentini ( van Ee & Berry 2011 ) . Distribution and habitat:— It occurs in southern Brazil ( PR , RS) ( Caruzo et al. 2020 ), where it grows in sandy or rocky soils of ‘cerrado’, between 800 and 995 m elevation. ( Fig. 14 ). Phenology:— Flowering and fruiting from October to February, and April to June. Representative specimens:— PARANÁ: Balsa Nova , São Luiz do Purunã , 05 October 2001 , J . M . Silva & O . S . Ribas 3473 ( MBM ); idem, 21 April 2010 , R . Ristow , L . J . B . Schip & W . T . Ferreira 609 ( IRAI , MBM ). Jaguariaíva , Estrada do Sertão , entrada grande, 04 December 1964 , G . Hatschbach 11967 ( K , MBM , UPCB ); Vale do Codó , 12 October 2006 , J . M . Silva , E . Barbosa & E . M . Cunha 5098 ( MBM , MG ). Palmeira , Fazenda Padre Inácio , 30 May 1971 , G . Hatschbach 26703 ( MBM ) .