Croton myrianthus Müller Argoviensis (1865: 138)

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 : 254

25. Croton myrianthus Müller Argoviensis (1865: 138) .

Type: — BRAZIL. ‘in Brasilia Meridionali’, s.d., F. Sellow 3936 (holotype B† ; lectotype SP 18550! designated by Lima & Pirani 2008b; isolectotypes A 00257962!, photo F 0 BN005137 !, G 00434607!, NY 00262931!) ( Fig. 15 , A–B).

Croton myrianthus is a shrub with subentire lepidote trichomes on both leaf surfaces, and unisexual inflorescences. Lima & Pirani (2008b) pointed out the similarities between C. myrianthus and C. uruguayensis , however, the two species can be distinguished by inflorescence size (up to 2 cm long in C. myrianthus vs. up to 7 cm in C. uruguayensis ), and by leaf shape (elliptical, ovate or ovate-lanceolate in C. myrianthus vs. narrowly elliptic to narrowly lanceolate in C. uruguayensis ). The species belongs to section Lamprocroton subsect. Lamprocroton ( van Ee & Berry 2011) .

Distribution and habitat:— It occurs in southern (PR, RS, SC) Brazil ( Caruzo et al. 2020), where it grows in open vegetation, frequently close to riverbanks, between 700 and 990 m of elevation ( Fig. 14 ).

Phenology:— Flowering and fruiting from October to March.

Representative specimens:— PARANÁ: Bituruna, Fazenda Lageado Grande, 987 m, 18 September 2004, D. Liebsch 798 ( UPCB). Dois Vizinhos , Foz do Chopim , 9 December 1968, G . Hatschbach 20578 ( MBM, NY, RFA, UPCB). General Carneiro, Fazenda São Pedro, Lagoa Sanguessuga , 01 October 2004, A. C . Cervi 8678 ( UPCB). Guarapuava, Rio Coitinho , 15 December 1965, R . Reitz & R. M . Klein 17657 ( NY, P). Palmas , 04 November 1998, A . Soares & W . Maschio 282 ( HFC, HUEM) .

Figures

FIGURE 14. Map showing the known geographic distributions of Croton myrianthus, C. polygonoides, C. pycnocephalus, and C. reitzii in Paraná state.

FIGURE 15. Croton myrianthus. A. Branches with silvery leaves. B. Capsules. C. pycnocephalus. C. Inflorescence. D. Habit. C. sanctaecrucis. E. Inflorescence. F. Leaf with sessile nectary gland. G. Staminate flowers. H. Pistillate flowers with bifid styles. I. Capsules. C. salutaris. J. Cut in the bark showing red latex. K. Leaf with stipitate nectary glands. L. Urceolate pistillate flowers. Photos: A–I: A.P.N. Pereira, J, L: R. Riina, K: O.L.M. Silva.