Euploca Nuttall (1836: 189)

Melo, José Iranildo Miranda De, Paulino, Renan Da Cruz, Oliveira, Regina Célia De & Vieira, Diego Daltro, 2018, Flora of Rio Grande do Norte, Brazil: Boraginales, Phytotaxa 357 (4), pp. 235-260 : 248

1. Euploca Nuttall (1836: 189) .

Heliotropium sect. Orthostachys (R.Br.) G. Don (1838: 361) .

Hilgeria Förther (1998: 132) .

Schleidenia Endlicher (1839: 646) .

Herbs to subshrubs. Leaves alternate or subopposite; sessile or petiolate; blade membranaceous to chartaceous; glabrous or pilose; venation brochidodromous or hyphodromous. Cymules terminal or axillary; with or without bracts; slightly to strongly scorpioid, solitary or in groups of 2–4, pedunculate, or rarely with solitary supra-axillary flowers. Flowers sessile or pedicellate; calyx of various forms; corolla hypocrateriform to tubular-hypocrateriform, white or purplish, yellow at throat, or less frequently, entirely yellow, lobes of various forms, margin undulate to undulate-plicate; stamens included, sessile or subsessile, anthers dorsifixed, introrse, oval to lanceolate, glabrous to pubescent, with glandular trichomes only at apex; ovary 4-locular, glabrous or pilose; 1 ovule per locule; style absent or present, sometimes inconspicuous, terminal, cylindrical; stigma 1; nectariferous disc at the base of ovary annular. Fruit schizocarpous, dry, with 4 one-seeded nutlets; calyx and stigma persistent; seeds ellipsoid or suborbicular, embryo curved.

Euploca includes about 120 species, distributed in tropical and subtropical zones, especially in arid and semiarid regions. The genus is represented in Brazil by 17 species ( Melo & Semir 2010), with five of them recorded for Rio Grande do Norte, in open environments, even in mountainous areas, or less frequently, in coastal dunes and the Atlantic Forest.