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

Emmeorrhiza umbellata (Spreng.) Schum., Mart. Fl. Bras. 6(6): 408. 1888.

Endlichera umbellata (Spreng.) Schum., Mart. Fl. Bras. 6(6): 38. 1888.

Examination of abundant herbarium material indicates a broad range of variation within the geographical range of E. umbellata, varying from pubescence and length of capsules, shape of calyx lobes, and glabrity or pubescence of pedicels, hypanthium, stems, and foliage. Material from the southern part of the range and from southern Brazil, where the type originated, shows shorter capsules and calyx lobes, the latter of narrower dimensions, in comparison with material from the northern part of the range, especially from that of the Guayana Highland and the northern Andes and Coastal Cordillera of Venezuela.

Most of the material from Brazil shows glabrous capsules and pedicels and usually glabrous stems. In his original description of Endlichera brasiliensis Presl (Symb. Bot. 1: 73. pl. 49. 1832), based upon a specimen collected near Bahia, Brazil, the capsule is described as only 2 mm (1 line) long, the calyx teeth as ovate, and the pedicels as glabrous. Sprengel does not give any dimensions for the capsule in his description of Borreria umbellata (basionym of Emmeorrhiza umbellata), but does state that the capsules are pubescent, whereas Presl described the capsules of his Endlichera brasiliensis as glabrous. Similarly, we encounter variations in statements regarding the leaf pubescence, Presl describing the leaves as pubescent beneath on the midrib and main nerves in Endlicheria brasiliensis, whereas Sprengel describes the leaves of Borreria umbellata as glabrous. Presl describes Emmeorhiza pohliana as having glabrous leaves, whereas those of Endlichera brasiliensis are described with the nerves scabrous on the lower side. Although the Brazilian material varies in leaf pubescence from glabrous to pubescent, most of the material has leaves mainly glabrous above and glabrous to sparsely pubescent beneath. The calyx lobes of the Brazilian material are generally narrowly to broadly lanceolate and 0.3-1 mm long, while the capsules are usually 2-3 mm long. A Sellow collection from Kew Herbarium, representing the type collection of Borreria umbellata, has glabrous stems, petioles, leaf blades, and hypanthium, while the calyx lobes in anthesis are shortly triangular-lanceolate and 0.5-0.6 mm long.

Under Borreria ? aralioides Chamisso & Schlechtendal described a specimen collected by Sellow in east-central Brazil, together with what was designated as Borreria umbellata collected at the same time by Sellow (Linnaea 3: 339-340. 1828), differentiating it from B. umbellata by the flower parts twice larger and in being glabrous throughout. Of the specimens at Kew Herbarium collected by Sellow of Emmeorrhiza umbellata, I have seen nothing that is not conspecific with that taxon. A specimen at NY from the Bentham Herbarium and labelled B. aralioides, collected from Rio Janeiro in 1837 by Tweedie (1233), is glabrous throughout and has the same measurements of corolla, calyx, and hypanthium as E. umbellata subsp umbellata of southern Brazil. The calyx lobes of the Tweedie specimen are triangular-lanceolate, 0.6-0.8 mm long, and the corolla length is 1.5-2 mm long.