Monographs Details: Retiniphyllum laxiflorum var. brasiliense Steyerm.
Authority: Maguire, Bassett. 1965. The Botany of the Guayana Highland. Mem. New York Bot. Gard. 12 (3): 1-285.
Family:Rubiaceae
Description:Latin Diagnosis - A var. laxiflorum differt lobis corollae 10-10.5 mm longis atque venulis subtus inaequaliter prominulis, rete magis laxiori majorique.

Discussion:The variation of the length of the corolla-lobes in R. laxiflorum breaks into a measureable pattern, as given in the key to the varieties, although there is some intergradation. While most of the material of var. laxiflorum has the apices of the leaf-blades rounded to obtuse, some of the specimens have subacute apices. There is also some variation in pubescence of the style, length of the filaments, and size of the fruits, but these cannot be correlated with other differences.