Authority:

Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.

Family:

Rubiaceae

Discussion:

Cassupa alba (Schum. in Engler & Prantl, nom. nud.) Schum. & Kr., Bot. Jahrb. 40: 322. 1908.

Isertia spraguei Wernh., Kew Bull. 1914: 65. 1914.

Isertia alba (Schum. & Krause) Standley, Field Mus. Publ. Bot. 8: 346. 1931.

Cassupa juruana Schum. & Krause, Bot. Jahrb. 40: 148. 1907, nomen.

Isertia juruana (Schum. & Krause) Standley, Field Mus. Publ. Bot. 8: 346. 1931.

Creatantha peruviana Standley, Field Mus. Publ. Bot. 8: 344. 1931.

Type. Between Pitalito and Mocoa, Colombia, Sprague s.n.

Sprague s.n., collected between Pitalito and Mocoa, Colombia, is the specimen upon which both Isertia alba and I. spraguei were based. Wernham redescribed the same specimen of Sprague, originally described and published by Sprague. Apparently this practice was one committed by Wernham on other occasions (see Sabicea for example). Standley also made an unnecessary new combination when he published I. alba (Schum. & Krause) Standley in 1931 based on Cassupa alba Schum., a nomen nudum in 1891, but legitimately described in 1908 by Schumann & Krause, thus antedating Standley’s description. It is not understandable why Standley omitted I. alba Sprague from his treatment of the Rubiaceae of Colombia (Field Mus. Publ. Bot. 7: 1-175. 1930).

Although I have seen only a photograph of the type of Cassupa juruana Schum. & Krause, I find no sharp distinctions in the original description to differentiate this species from Isertia alba Sprague. The reticulation of the tertiary nerves on the lower leaf surface, manifesting the fine dark lines of the veins outlined against the silvery-gray background serves as a criterion by which it is possible to refer the same type of leaf found in I. alba in both Colombia and Peru.