Monographs Details:
Authority:
Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
Family:
Rubiaceae
Rubiaceae
Description:
Species Description - The following differences summarize the contrasts between Rondeletia and Arachnothrix. Capsule loculicidally dehiscent; seeds fusiform, winged, caudate at one or both ends, the testa shallowly reticulate with elongated cells; orifice of corolla with a conspicuous thickened annular callosity; tube of corolla glabrous within; corolla lobes 5; calyx-lobes 5; disk densely hirsutulous, projecting above the sinus at the base of the calyx-lobes, the calyx-tube not developed or obsolete; stipule inconspicuous, triangular or deltoid; pubescence of hypanthium, outer surface of corolla, or vegetative parts usually not pannose nor arachnoid-pubescent. Rondeletia. Capsule septicidally dehiscent; seeds rhomboidal to triangular, compressed, not winged nor caudate, the testa deeply foveolate and rugulose thickened with sunken pentagonal or hexagonal cells; orifice of corolla naked, without a thickened callosity; tube of corolla pubescent within in basal portion; corolla-lobes 4; calyx-lobes 4; disk usually glabrous, sunken below sinus at the base of the calyx-lobes, the calyx-tube obviously manifest; stipule conspicuously developed, oblong or oblong-lanceolate; pubescence of hypanthium or vegetative parts usually pannose or arachnoid-pubescent. Arachnothrix.
Distribution and Ecology - The main centers of distribution of Rondeletia are the West Indies, Central America, and Mexico. As interpreted in the present study, the South American species, previously assigned to Rondeletia, fall into two genera: (1) Rondeletia and (2) Arachnothrix. The South American species in general are more closely allied to the Mexican and Central American than they are to the West Indian species.
Species Description - The following differences summarize the contrasts between Rondeletia and Arachnothrix. Capsule loculicidally dehiscent; seeds fusiform, winged, caudate at one or both ends, the testa shallowly reticulate with elongated cells; orifice of corolla with a conspicuous thickened annular callosity; tube of corolla glabrous within; corolla lobes 5; calyx-lobes 5; disk densely hirsutulous, projecting above the sinus at the base of the calyx-lobes, the calyx-tube not developed or obsolete; stipule inconspicuous, triangular or deltoid; pubescence of hypanthium, outer surface of corolla, or vegetative parts usually not pannose nor arachnoid-pubescent. Rondeletia. Capsule septicidally dehiscent; seeds rhomboidal to triangular, compressed, not winged nor caudate, the testa deeply foveolate and rugulose thickened with sunken pentagonal or hexagonal cells; orifice of corolla naked, without a thickened callosity; tube of corolla pubescent within in basal portion; corolla-lobes 4; calyx-lobes 4; disk usually glabrous, sunken below sinus at the base of the calyx-lobes, the calyx-tube obviously manifest; stipule conspicuously developed, oblong or oblong-lanceolate; pubescence of hypanthium or vegetative parts usually pannose or arachnoid-pubescent. Arachnothrix.
Distribution and Ecology - The main centers of distribution of Rondeletia are the West Indies, Central America, and Mexico. As interpreted in the present study, the South American species, previously assigned to Rondeletia, fall into two genera: (1) Rondeletia and (2) Arachnothrix. The South American species in general are more closely allied to the Mexican and Central American than they are to the West Indian species.
Discussion:
Type. Rondeletia americana L.