Monographs Details: Diodia hyssopifolia var. linearis f. glabriuscula Steyerm.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Description:Latin Diagnosis - A var linearis caulibus glabris vel duobus lateribus puberulentibus recedit; stipularum vaginis glabris vel parce puberulentibus; foliis subtus glabris.

Discussion:

This variation shows the broad leaves of var linearis, but the lower surface of the leaves is glabrous, the stems are glabrous or have lines of puberulence on two sides, and the sheaths of the stipules are glabrous or with lines of puberulence.

Two collections which appear intermediate between D. hyssopifolia var hyssopifolia f psiloclada and var linearis f glabriuscula with short calyx lobes are: Cowan & Wurdack 31554 (Serrania Parú, Río Parú, Caño Asisa, on playas, alt 150 m, 18 Feb 1951, Amazonas, Venezuela) and Pires, Rodrigues & Irvine 51585 (rocks of Cachoeira Pedra Fina, Camp 13, 1° 45' N-25° W, Amapá, Brazil).