Monographs Details: Neobertiera gracilis Wernham
Authority: Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
Family:Rubiaceae
Description:Distribution and Ecology - British Guiana. BRITISH GUIANA. Rockstone, Gleason 483; wet lowland forest, Tumatumari, Gleason 6; Moraballi Creek, near Bartica, Esse-quibo River, Sandwith 256; basin of Essequibo River, lat about 6°7'N, Head Falls, A. C. Smith 2106.

Discussion:

Careful study of specimens determined as Neobertiera gracilis requires a change of tribal position and emendation of several characters. The fruit is a dry capsule, instead of a berry, as described by Wernham, there are numerous instead of few ovules in each cell of the ovary, and the flowers are 4-5 merous. The above specimens, together with Jenman 2388 (type of N. gracilis), obviously show a close relation to other members of the Rondeletieae, such as Sipanea. Specimens of the above cited were identified by Standley as an unpublished species of Sipanea, and N. E. Brown, commenting on the Gleason 6 specimen, noted that “This plant is so exactly like a Pteridocalyx [a member of the Rondeletieae tribe] in everything except the petaloid calyx-lobe, that I think it should go in that genus rather than in Sipanea,” and Brown determined it as the same as Gleason 483. The dry fruit, numerous ovules and seeds, and contorted corolla-lobes place it near Sipanea in the Rondeletieae. Sandwith ( Kew Bull. 1931: 470. 1931) noted that although Wernham described the flowers of N. gracilis as tetram-erous, even on the type specimen (Jenman 2388) at least two of the flowers are pentamerous, while pentamery is obvious on the Kew specimen.

Although Neobertiera may be placed close to Sipanea, it differs in several important respects. The stamens in Neobertiera are inserted near or at the base of the corolla-tube instead of above the middle, the corolla-lobes are linear-oblong to narrowly lanceolate and 2 1/2 -3 times as long as broad, whereas in Sipanea they are relatively proportionately broader and of different shape. In Neobertiera there is no sessile central flower with lateral 1- to 2- or more branched dichasia as in Sipanea. Instead, there are three or more main branches with a pedicellate central flower. Moreover, there are no yellow villous elongate hairs projecting from the orifice of the corolla as in some species of Sipanea, but instead is a somewhat thickened portion at the orifice with white papilla-like villae and white seta-like hairs occur at the base of the middle part of the corolla-lobes. The calycine squamellae do not arise at the sinus but at the base on either side of the calyx-lobe, thus two squamellae are evident between the calyx-lobes.

Distribution:Guyana South America|