Monographs Details: Microlicia benthamiana Triana ex Cogn.
Authority: Maguire, Bassett & Wurdack, John J. 1958. The botany of the Guayana Highland--Part III. Mem. New York Bot. Gard. 10: 1-156.

Microlicia bryanthoides Oliv. Timehri 5: 192. 1886.

Microlicia steyermarkii Gl. Fieldiana Bot. 28: 425. 1952.

Twenty-nine different collections, twenty of which have been made since 1950, have been studied; included in this material have been the holotypes of all three names. Despite many permutations of these collections, no practical means of separating subspecific categories is apparent. Were such variability accepted within the many Brazilian species of Microlicia, the recognized categories would perhaps be one-third of the present total.

The sepal shape, degree of connective prolongation development, and especially the size, shape, and punctation of the leaves of M. benthamiana all vary independently of one another in the various collections. The leaves of most recent collections do not quite reach the maximum width of 3 mm seen in Schomburgk 151.5 (the type number of M. benthamiana), although one sprig of Maguire 33570 has leaves slightly exceeding 3 mm. Several evolutionary pseudopods have appeared, the most definite being in Maguire & Maguire 40426 and 40391; in these Serra do Sol specimens, the leaves are remarkably crowded and almost epunctate, only the leaf margins showing glands. Most of the variability within M. benthamiana can be seen in the series Maguire & Maguire 35117, 35278, 35347, all from Cerro Yutaje. A series showing slightly different lines of variation is the material from Chimanta-tepui. Morphologically, M. steyermarkii is very similar to the type of M. benthamiana, with slightly narrower and slightly more punctate leaves.

The following description incorporates the observed variability; Shrubs 0.1-3 m, glabrous. Leaf blades 4-9 X 0.7-3 mm, elliptic to oblanceolate, the apex rounded to acute, the base acute to narrowly acute, above epunctate to densely punctate, below sparsely to densely punctate (the margins in densely punctate leaves appearing subcrenulate), usually faintly trinerved with apically evanescent laterals; petioles scarcely distinct, sometimes calloused, to 0.8 mm long. Flowers solitary on short foliose branches. Hypanthium 2-3.5 mm long, more or less densely covered with reddish to yellow glands. Sepals 2-4.6 X 0.6-1.5 mm, usually about equaling the hypanthium in length, linear to narrowly triangular, acute (in Maguire & Maguire 35347 tipped with a seta to 0.3 mm long). Petals 6.8-12 X 3.5-6.8 mm, asymmetrically obovate to subelliptic, usually pink (one plant, Steyermark of- Wurdack 442, with white petals, among a large pinkpetaled population). Large stamens: filaments 3-5.5 mm; anthers short-rostrate, 2-2.8 mm long; connective below the anther 2.1-5.6 mm to the filament insertion, straight for about % of this length, below the insertion 1.2-2.3 X 0.3-1 mm and gradually widened to the rounded to truncate apex. Small stamens: filaments 2.4-5.3 mm; anthers short-rostrate, 1.3-2.4 mm long; connective below the anther 0.5-2.4 mm to the filament insertion, straight for almost the entire length, below the insertion 0.3-0.9 X 0.2-0.35 mm and scarcely widened to the rounded to slightly emarginate apex.