Euphorbia Linnaeus (1753: 450)

Silva, Otávio Luis Marques Da, Cordeiro, Inês & Caruzo, Maria Beatriz Rossi, 2014, Synopsis of Euphorbia (Euphorbiaceae) in the state of São Paulo, Brazil, Phytotaxa 181 (4), pp. 193-215 : 194-195

Euphorbia Linnaeus (1753: 450) .

Lectotype (designated by Millspaugh 1909: 306):— Euphorbia antiquorum Linnaeus (1753: 450) .

Perennial or annual herbs, shrubs or rarely trees or climbers, prostrate or erect, monoecious or rarely dioecious, glabrous or pubescent, with white milky latex; stems green to reddish, succulent and spiny in some species. Leaves alternate, opposite or verticillate, generally petiolate, stipulate or exstipulate, simple, entire or lobate, glabrous or pubescent, penninerved or palminerved. Inflorescences axillary or terminal, cyathia solitary, in dichasia, pleiochasia or monochasia, usually subtended by bracts (cyathophylls), sometimes showy; cyathia consisting of four or five staminate cymules, with 1–10 flowers each, with or without associated bracteoles, surrounding one terminal pistillate flower, inside a cuplike, gland-bearing involucre, with or without appendages; staminate flowers in lateral cymules, reduced to a single stamen with a slender pedicel; pistillate flower solitary, terminal, achlamydeous (sometimes ovary subtented by a perianth-like structure); ovary (2–)3–locular; styles (2–)3, free or connate, generally bifid; stigmas thickened or not. Fruit capsule, septicidally and loculicidally dehiscent into (2–)3, 2-valved cocci, dehiscence explosive, or rarely fleshy and indehiscent; columella persistent. Seeds generally ovoid; raphe longitudinal on the ventral face; seed coat smooth or ornamented, carunculate or ecarunculatae.

In the State of São Paulo, Euphorbia is represented by 23 species of three of the four subgenera currently recognized. The subgenus that has no representatives in São Paulo is subg. Athymalus, which is restricted to Africa.

Most of species recorded for São Paulo belong to subg. Chamaesyce , and three sections are represented in the state: sect. Anisophyllum Roeper in Duby (1828: 412) (11 spp.; Euphorbia adenoptera , E. bahiensis , E. foliolosa , E. hirta , E. hyssopifolia , E. ophthalmica , E. potentilloides , E. prostrata , E. serpens , E. setosa and E. thymifolia ), sect. Alectoroctonum ( Schlechtendal 1847: 252) Baillon (1858: 284) (2 spp.; E. insulana and E. sciadophila ) and sect. Poinsettia ( Graham 1836: 412) Baillon (1828: 284) (2 spp.; E. heterophylla and E. zonosperma ).

The subgenus Euphorbia is represented by seven species, from two sections: sect. Nummulariopsis Boissier (1862: 71) (6 spp.; Euphorbia chrysophylla , E. cordeiroae , E. elodes , E. papillosa , E. peperomioides and E. rhabdodes ) and sect. Stachydium Boissier (1862: 65) (1 sp.; E. comosa ). Subgenus Esula is represented by only one species, E. peplus , which belongs to sect. Tithymalyus ( Gaertner 1790: 115) Roeper in Duby (1828: 412).