Croton tricolor Klotzsch ex Baillon (1864: 291)

Rossine, Yuri, Melo, André Laurênio De, Athiê-Souza, Sarah Maria & Sales, Margareth Ferreira De, 2021, Taxonomic updates in Brazilian species of Croton sect. Lasiogyne (Euphorbiaceae): new synonyms and lectotypifications, Phytotaxa 490 (1), pp. 82-90 : 88

Croton tricolor Klotzsch ex Baillon (1864: 291) .

— Oxydectes tricolor (Klotzsch ex Baill.) Kuntze (1891: 613) .

Lectotype (first step designated by Gomes et al. [2010a: 907], second step designated by van Ee [2011: 31]):— BRAZIL. Minas Gerais: without further locality, without date, A.F.C.P. de Saint-Hilaire, cat C 1, n. 92 ( P [ P634797 !] ; isolectotypes: A [ A303790 !, A303791 !], F [ F77753F !], P [ P634794 !, P634795 !]) .

Croton argyrophylloides Müller Argoviensis (1865: 96) .— Oxydectes argyrophylloides (Müll.Arg.) Kuntze (1891: 611) . Lectotype (designated here):— BRAZIL. Bahia: “secus Rio Francisco ”, 1838, J.S. Blanchet 2835 (G [G434466!]; isolectotypes: BR [BR8526595!], C [C 10011157!], F [F0 BN005054 !], G [G311380!, G434466!], P [P634797!, P634798!]).

Croton rufo-argenteus Müller Argoviensis (1873: 135) .— Oxydectes rufoargentea (Müll. Arg.) Kuntze (1891: 612) , syn. nov. Lectotype (designated here):— BRAZIL. Minas Gerais: “ Prope Funil ad Rio Paraopeba et ad Rio Macacos ”, 24 April 1866, J.E.B. Warming 1554 (C [C10011192!]; isolectotype: G [G434621!]).

Notes: — Croton argyrophylloides was published by Müller Argoviensis (1865) based on Blanchet 2835, without indication of the herbarium. Many specimens at JSTOR are indicated as types of C. argyrophylloides . We considered syntypes only those with annotations from the author and/or collector, and from the area of the São Francisco River, since none has the exactly “prov. Bahiensi secus Rio Francisco” annotation from the protologue. The specimen G434466 is selected as lectotype because of its open staminate and pistillate flowers.

Müller Argoviensis (1873) described Croton rufo-argenteus and placed it in C. sect. Eucroton subsect. Cleodora ( Klotzsch 1841: 196) Müller Argoviensis (1873: 133) , considering it close to C. orinocensis Müller Argoviensis (1873: 135) , belonging to the same section. Croton rufo-argenteus was differentiated from C. orinocensis by the eglandular leaf base and by a smaller calyx of the pistillate flower. When analyzing the protologues and types of C. rufo-argenteus and C. tricolor , it was noted that they do not differ morphologically. Thus, the synonymization of C. rufo-argenteus under C. tricolor is proposed here. Also, Müller Argoviensis (1873) published C. rufo-argenteus based on Warming 1554, without mentioning the herbarium. Since the type collections are deposited in G and C, and both were clearly examined by the author, it is necessary to choose a lectotype. The specimen from C is best preserved, and is here selected as lectotype of C. rufo-argenteus ( Figure 2 ).

Croton tricolor is mainly characterized by the silver to ferruginous lepidote indumentum on the young branches, abaxial surface of the leaf blade, inflorescences and fruit, the lanceolate to auriculate stipules, the pistillate flowers with ovate to oblong, reduplicate sepals, the multifid styles, and by the rugose seed surface.

Figures

FIGURE 2. Lectotype of Croton rufo-argenteus at C, specimen C10011192. Reproduced with permission of the Natural History Museum of Denmark.