4. Croton calycireduplicatus Allem (1979: 67) .

Type:— BRAZIL. Rio Grande do Sul: Vacaria, Passo do Socorro, em campos secos arbustivos, 27 December 1951, B. Rambo s.n. (PACA 51528!) (Illustration available in Allem 1979: 68).

The species has few records for the state of Paraná, two field trips were made to verify its distribution range, but unfortunately, it was not found. Croton calycireduplicatus is a shrub that can be recognized by its slightly laciniate pistillate sepals, and conspicuous reduplicate-valvate aestivation. We did not see any specimens with pistillate and staminate flowers in the same individual, which may indicate that C. calycireduplicatus is a dioecious species. Collections of C. calycireduplicatus were previously misidentified as C. montevidensis Sprengel (1826: 873) . The latter species occurs in Uruguay and Brazil (RS), and its distribution is restricted to the Pampa biome. These species are very similar morphologically but can be distinguished mainly by their habitats and by the margins of sepals of the pistillate flowers (serrate in C. calycireduplicatus vs. entire in C. montevidensis). The species is a member of section Barhamia subsect. Medea (Klotzsch 1841: 193) Pax (1890: 39) (van Ee et al. 2011).

Distribution and habitat:— It occurs in southern Brazil (RS, SC) (Smith et al. 1988, Caruzo et al. 2020), and we report this species for the Paraná state for the first time (Fig. 2). Plants were found in edges of Araucaria forest and sandy soil along riverbanks, between 700 and 900 m elevation.

Phenology:— Flowering and fruiting November to December.

Representative specimens:— PARANÁ: Palmeira, Rod. Curitiba– Ponta Grossa, Rio Tibagi, 03 November 1975, R . Kummrow 975 (MBM); 03 November 1975, R . Kummrow 976 (MBM). Rio Branco do Sul, Brumado, 06 December 1995, G . Hatschbach, L . Landrum & L . Kawasaki 64024 (MBM). Tibagi, próximo ao Rio Barrinha, 28 November 1993, F . Chagas e Silva 1668 (FUEL, HCF) .