Monographs Details: Diodia ocimifolia (Willd. ex Roem. & Schult.) Bremek.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Discussion:

Spermacoce ocymifolia Willd. in R. & S., Syst. Veg. 3: 530. 1819.

Spermacoce longifolia Aubl. ex Miq., Symb. Fl. Surin., Linnaea 18: 299. 1844.

Spermacoce longifolia f. glabrata Miq., Linnaea 18: 300. 1844.

Hemidiodia ocimifolia (Willd.) Schum., Mart. Fl. Bras. 6(6): 30. pl. 72. 1888.

I concur with Bremekamp in relegating Hemidiodia to synonymy under Diodia. The weakness and relative degree of rupturing of the inner face of the cocci varies in different species of Diodia, reaching an extreme in Hemidiodia. Without other significant distinctions to separate Hemidiodia ocimifolia, it seems prudent to unite it congenerically with Diodia. In addition to frequent confusion of this taxon with Diodia sarmentosa, from which it may be distinguished by the characters presented in the key to species of Diodia, it is often confused with Spermacoce confusa, the latter differentiated immediately by its included instead of exserted stamens, glabrous stems and angles of stems, upper leaf surface conspicuously scabrid, and capsules more hispid with longer and stiffer hairs.