Borreria suaveolens G. F. W. Mey., Prim. Fl. Esseq. 81. pl. 1. 1818.
Borreria tenella var suaveolens (Mey.) Schum., Mart. Fl. Bras. 6(6): 56. pl. 76, fig 2. 1888, excl. Brazilian specimens.
Borreria suaveolens proves to be a rare variation of the B. capitata complex. Meyer’s taxon appears to have been confused and misinterpreted by most later authors. It was correctly identified as B. suaveolens, however, by Bentham (Hook. Jour. Bot. 3: 237. 1841) on the basis of a Schomburgk 250 collection, cited by Schumann (Mart. Fl. Bras. 6(6): 56. 1888) as B. tenella var suaveolens. Meyer’s plate and description relates to a plant having 4 calyx teeth, definitely developed in figures g-1 and q-r of his plate 1, while figures s-v show corresponding halves of the capsule, each with 2 teeth attached to each half. These teeth are figured as equally long and manifest, and in the specimens of Schomburgk 250 from British Guiana and of Pinas 8367 from Suriname are 1.8-2.5 mm long. The corollas of the Schomburgk, Harrison, and Pinas specimens are relatively large, measuring 3.8-5.5 mm long. The relatively large corollas and 4 rather equal and elongated calyx lobes show the affinity of B. suaveolens to Spermacoce tenella H.B.K. (= B. capitata var tenella). The latter shows variations in the length of internodes, branching of stem, glabrity of the angles of the stem, length of leaves, and extent of development of shorter leaves in the leaf axils.
The conspicuously reduced leaves occurring in prominent verticils, with relatively short internodes, as shown in Meyer’s plate of B. suaveolens, combined with glabrous stems, is matched by the specimens of Schomburgk 250, Harrison 1046, and Pinas 8367. However, there appears to be no sharp line of demarcation between this completely verticillate type of leaf development in B. suaveolens and the various transitional manifestations of axillary leaves shown in the specimens cited under B. capitata var tenella of specimens of Pennell 5531, Rusby & Pennell 430, Pennell & Killip 8108, Lehmann 8538, Toro 453, and Holton 418, all from Colombia; and Steyermark & Nilsson 579, Tamayo 111 and 3720, Pittier 9606 and 10556, Steyermark 58538, and B. & C. K. Maguire 35466, these from Venezuela. In such specimens the principal leaves are elongated, but shorter axillary leaves are also present, whereas in B. suaveolens the verticils of leaves are all reduced to 3 more or less equal short blades 0.7-3.5 cm long by 0.15-0.3 cm broad.
This rarely encountered variation with the leaf verticils of 3 more or less equal reduced blades, 4 more or less equal elongated calyx lobes, and relatively large flowering heads and corollas is the type described and illustrated by Meyer, but it has been confused with a commoner plant found in the savannas of the Guianas and Venezuelan Guayana. Although most authors have confused it with B. suaveolens, it is at variance with Meyer’s taxon, and is described below.