Euphorbia potentilloides Boissier 1860

16. Euphorbia potentilloides Boissier (1860: 3) (Fig. 5F–H). Lectotype (designated here):— BRAZIL. Goiás: Chapadas de San-Marcos, N.T. Lund s.n. (G00311067!); remaining syntype: same locality, L. Riedel s.n. (LE, isosyntype K!). Distribution and habitat:— Euphorbia potentilloides occurs in Brazil, Argentina, Bolivia, Paraguay and Uruguay. In the State of São Paulo the species occurs in cerrado vegetation. Representative Specimen:— BRAZIL. São Paulo: Pedregulho, 30 October 2013, O.L.M. Silva et al. 96 (SP). Taxonomic notes:— Euphorbia potentilloides is morphologically diverse, but this variation is restricted mostly to the vegetative characteristics (leaves and cyathophylls; see Simmons & Hayden 1997). The species may be easily recognized among the others species with interpetiolar stipules, opposite leaves and cyathial glands with petaloid appendages occurring in the State of São Paulo because it is the only one with cyathia arranged in pleiochasia. Also, the species may bear up to 7 cyathial glands (although in São Paulo state only specimens with up to 6 cyathial glands were observed) and has smooth seeds, a characteristic found only on Euphorbia serpens, from which it differs by its erect stem (vs. prostrate in E. serpens), linear to narrowly elliptic leaves (vs. orbicular in E. serpens) and cyathia in pleiochasia (vs. solitary in E. serpens).Published as part of Silva, Otávio Luis Marques Da, Cordeiro, Inês & Caruzo, Maria Beatriz Rossi, 2014, Synopsis of Euphorbia (Euphorbiaceae) in the state of São Paulo, Brazil, pp. 193-215 in Phytotaxa 181 (4) on page 205, DOI: 10.11646/phytotaxa.181.4.1, http://zenodo.org/record/514613