TWO NEW SPECIES OF COUSSAREA AND A NEW COMBINATION IN FARAMEA ( RUBIACEAE , COUSSAREEAE ) FROM THE GUIANAS

During the preparation of the treatment of the family Rubiaceae for the Flora of the Guianas, two new species of Coussarea were discovered. One species, Coussarea longilaciniata, was collected in Guyana and is characterized by its long-lanceolate calyx lobes; the other, C. spicata, is from French Guiana and is unique in the genus by its spicate inflorescences. In addition, Faramea sessiliflora var. pedunculata is here elevated to the species level, and a new description of F. sessiliflora is also provided in view of the re-delimitation of this species.


INTRODUCTION
Coussarea, of about 110 species, and Faramea, of about 130 species, are sister genera in the tribe Coussareeae (sensu Andersson & Rova, 1999, f. 3).A third genus, Schizocolea Bremek., endemic to tropical Africa, was suggested to belong to this tribe (Bremekamp, 1951;Petit, 1962;Robbrecht, 1988).It differs from the other two by its stipules basally long-tubular and distally fimbriate; its systematic position remains uncertain.In addition, the generic boundary between Coussarea and Faramea is not well defined, since it is mostly based on stipule shape (triangular or rounded in Coussarea vs commonly aristate or rarely triangular in Faramea), fruit morphology (1-seeded, by abortion of one ovule, in Coussarea vs 1-or 2-seeded in Faramea), and corolla colour (white in Coussarea vs blue or white in Faramea) which are all characters that intergrade.The geographic distributions of Coussarea and Faramea are also similar, since both genera are restricted to the Neotropics, and their main centres of diversity are the Andean cloud forests, the Brazilian Atlantic forests, and the Guayana Shield.The two taxa might, therefore, even be congeneric.However, for the moment the two genera are defined according to the traditional delimitations adopted by Bremekamp (1934a, b), Steyermark (1967Steyermark ( , 1974)), Boom & Delprete (2002), and Taylor & Steyermark (2004).A revision of the species of Coussarea and Faramea occurring in the Guayana Highlands and contiguous areas was published by Steyermark (1967), where he recognized 20 species of Coussarea and 30 of Faramea.More recently, the species of Coussarea and Faramea from central French Guiana (Saül) have been studied by Boom & Delprete (2002), who also described a new species of Coussarea from that area (Delprete & Boom, 1999).In addition, a treatment of the species of these two genera occurring in the Venezuelan Guayana was recently published by Taylor & Steyermark (2004), facilitating the present study.
Ecology -Disturbed forests at 90 m altitude, and tall wet forests at 650 m altitude, on red lateritic soil.
Phenology -The two fruiting collections were made in March and April.Notes -Because of the large calyx, C. longilaciniata is most similar to C. macro calyx Standl., which is restricted to western Colombia and western Ecuador (cf.Taylor, 1999: 262), from which it differs by having persistent stipules (vs caducous in C. macrocalyx), inflorescence 3-7-flowered, comprised of 1 or 2 short branches (vs many-flowered, paniculate, with 2 or 3 pairs of secondary branches in C. macrocalyx), and calyx lobes long-lanceolate, 16-18 mm long (vs calyx lobes triangular to narrowly triangular, 1.5-5 mm long in C. macrocalyx).
Distribution -French Guiana, only known from the type collection.
Ecology -Submontane forest, on the plateau of the Atachi Bacca Mt, at 780 m altitude.
The type specimen of C spicata has previously been identified as C. leptoloba; however, the latter can be distinguished from the former by the leaf blades with 11 or 12 secondary veins each side (vs 15-17 each side in C. spicata), inflorescences trichotomous, 1.3-2.5 cm long (vs interrupted-spiciform, 12-13 cm long in C. spicata), and fruits uniformly pubescent (vs with two types of hairs, densely golden-puberulent and sparsely erect-pubescent, in C. spicata).Bremekamp (1957) and Steyermark (1967) distinguished Faramea sessiliflora var.pe dunculata Bremek.from the typical variety because of the "peduncles 1-2.5 cm long" (vs "peduncles absent" in var.sessiliflora).Steyermark had some doubts about maintaining the two varieties separate, because the respective types were both collected at the same locality (Kaw Mts, French Guiana) and the scanty specimens available.Recent collections from wider geographic ranges showed that many additional characters are present to distinguish the two taxa, and var.pedunculata is here raised to species level.Faramea pedunculata (Bremek.)Delprete is easily distinguished from F. sessiliflora Aubl.because of the pale orange, 20-28 by 7-17 mm, readily caducous bracts (vs green, 12-15 by 5-7 mm, persistent bracts in F. sessiliflora), calyx with 4 linear lobes (vs truncate or undulate in F. sessiliflora), corollas 29.5-35.5 mm long (vs 17-22 mm long in F. sessiliflora), anthers 2.8-3 mm long (vs 4.5-5 mm long in F. sessiliflora), style 15-16.5 mm long (vs 10-11 mm long in F. sessiliflora), and fruits ebracteate, globose to subglobose, 13-17 by 11-13 mm (vs fruits subtended by permanent bracts, transversally oblong-ellipsoid, 3.5-5 by 8.5-11 mm).In addition, because of the change of status of var.pedunculata, it is necessary to provide a new description of F. sessiliflora in order to re-delimit this species.

FARAMEA
With the new rearrangements here proposed and as a result of the ongoing studies, about 22 species of Faramea are known to occur in the Guianas.
Phenology -Flowering specimens were collected in December and January; fruiting specimens were collected in April, June, September and October.
Distribution -Widespread through the Amazon Basin, in Suriname, French Guiana, and in the Brazilian states of Amazonas, Mato Grosso and Pará.
Ecology -Undercanopy shrub or treelet, in gallery forests, at 80-150 m altitude.Phenology -Flowering from September through December, and fruiting from April through August.
Notes -Faramea sessiliflora was described and illustrated in Aublet's (1775) 'Histoire des plantes de la Guiane Françoise'; while in the text (p.104) the name of this species was spelled "FARAMEA (sessiflora)", in the figure legend (t.40, f. 2) the specific epithet was written "sessiliflora".The name of the figure legend was adopted by all subsequent authors, and is therefore here maintained.Aublet's text provides a detailed description of the taxon, and the rather simple figure shows the terminal inflorescence with three subsessile axes, each one with a pair of bracts enclosing the flowers, as it can be confirmed by the type specimen preserved at BM, and therefore clarifying the identity of this species.
Faramea sessiliflora is unique within the genus by its terminal, sessile inflorescences, with 3 short axes 1-3.5 mm long, each with two green, persistent bracts that subtend the fruits at full maturity.