Monographs Details: Diodia hyssopifolia var. linearis Steyerm.
Authority: Maguire, Bassett. 1972. The botany of the Guayana Highland--part IX. Mem. New York Bot. Gard. 23: 1-832.
Family:Rubiaceae
Discussion:

Spermacoce linearis Willd. ex R. & S., Syst. Veg. 3: 532. 1818; H.B.K. Nov. Gen. & Sp. 3: 343. 1819.

The collection of Vareschi & Magdefrau 6774 is an excellent match for the type of Spermacoce linearis, and was collected from the same general area. The type shows the leaves linear, 1-nerved, 3-4 cm × 2-3.2 mm, obviously densely hirtellous-pubescent stems with puberulent stipular sheaths, and internodes 2.5-3.3 cm long. The collections of Vareschi 7566 and of Weiss & Schmidt 86 have the leaves narrowed to a subpetiolate base and with 3-5 pairs of lateral nerves. The type described by Humboldt and Bonpland and represented by the photo of the type at B is the variation with broad leaves, puberulous lower leaf surface, hirtellous stems, and puberulent stipular sheaths. The leaves vary from 3-6 cm × (3-)4-7(-9) mm. The calyx lobes generally average longer and narrower than in typical var hyssopifolia, 1-1.5 × 0.2-0.4 mm, and are linear-lanceolate to narrowly lanceolate.