Description originale
Lachenaud, O., Bruniera, C. & Zappi, D. 2022. Six new and a little-known species of Rudgea (Rubiaceae—Palicoureeae) from the Guianas. Phytotaxa, 531(3): 154-174.

 

Statut pour la Guyane française
Lachenaud, O., Bruniera, C. & Zappi, D. 2022. Six new and a little-known species of Rudgea (Rubiaceae—Palicoureeae) from the Guianas. Phytotaxa, 531(3): 154-174. [GF = S]

 

Date de publication : Phytotaxa, 531(3): 171-173, fig. 9-10. 2022 [21/01/2022].

Distribution : Espèce connue des forêts à tendance submontagnarde (350-750 m) du centre et du sud de la Guyane française (basse Approuague?, Itoupé, Galbao, Bellevue de l’Inini, Tumuc Humac [y compris côté Suriname]) ; également une donnée excentrée du NW Amazonas (Uatumã).

Ecologie : Fleurs inconnues. Jeunes fruits observés en janvier et mars, fruits mûrs en août et novembre.

Taxonomie : Avant sa description, les collectes de Guyane ont été successivement nommées Rudgea (cf.) standleyana Steyerm. 1967 par J.H. Kirkbride et J.A. Steyermark à partir de 1973, puis R. sandemannii Sandwith 1949 et Coussarea violacea Aubl. 1775 par C.M. Taylor en 1994, Rudgea sp.B par Delprete en 1999 (Boom & Delprete in Mori et al. 2002), R. cornifolia (Kunth) Standl. 1931 par D. Zappi en 2006, et enfin Rudgea sp.A par D. Zappi en 2009.
D'après Lachenaud et al. (Phytotaxa, 531(3): 171-172. 21/01/2022): "This species is quite distinct from all other so far recorded in the Guianas, though in the absence of flowers it is difficult to suggest any affiliation with other species of the genus. The large white to yellow fruits with a conspicuously enlarged calyx scar are especially diagnostic (species of Rudgea occurring in the Guianas have mostly red or orange fruits, or if white, much smaller). In this character, and also in the leaves, pyrenes, seeds and inflorescences, Rudgea leucocarpa resembles Carapichea verrucosa C.M. Taylor (in Taylor & Gereau 2013: 124) from western Amazonia (Peru, Colombia, Brazil), although the latter has even larger fruits (2.5–3 × 2–2.5 cm) with a distinctly warty surface, and its stipules are distinctly longer than broad and apparently not fimbriate. Both species are known from fruiting material only, and have never been studied phylogenetically, so it is unclear whether their resemblance is superficial or indicative of a true relationship. Carapichea verrucosa is unusual in its genus and its position remains uncertain, although the stipules seem to exclude it from Rudgea. In vegetative characters R. leucocarpa also shows a superficial resemblance to R. graciliflora, but the latter has smaller fruits with the calyx not enlarged and a purplish-brown (when immature) or orange-red (when mature) colour, the leaf midrib concave above, and the stipules with a dorsal keel bearing apical appendages, while those of R. leucocarpa are dorsally flat and marginally fimbriate.
This species was already recognized as probably new by Boom & Delprete (2002: 646). The inflorescences, described by these authors as paniculate, are in fact more commonly glomerulate (the ramifications, if present, being very short). The internal sheath of the stipules apparently tends to disintegrate early in their development, and is often not visible on herbarium material. According to the label of Bordenave 1248, the texture of the fruits is reminiscent of marshmallow paste (“pâte de guimauve”)."

Type : Guyane française, sommet Tabulaire [Mount Itoupé], versant sud, forêt dense, 400 m, 24/08/1980, fruits. Arbuste du sous-bois 1,5 m. Fruits subsphériques blanc verdâtre, de 1,5 cm de diamètre. J.-J. de Granville 3587 (HT: P06800583 [Rudgea standleyana Steyerm. 1967, det. P.G. Delprete & F. Crozier, 1999]; IT: CAY079068, CAY079069 [R. standleyana, det. P.G. Delprete & F. Crozier, 1999], NY n.v.).
Guyane française, basse Approuague, saut Tortue, 4°11’N, 52°24’W, bord de route forestière, 350 m, 17/11/1994, fruits. Arbuste 1,3 m. Fruits blancs sphériques, de 3 cm de diamètre (cf. pâte de guimauve). B. Bordenave 1248 (PT: P04008947 [R. standleyana, det. J.-J. de Granville, 1994]).
Guyane française, Pente NE des monts Galbao, 500-600 m, 11/03/1975, jeunes fruits. Arbuste 1-1,5 m. Fruits elliptiques vert clair. J.-J. de Granville 2386 (PT: CAY007584 [R. sp.B, det. P.G. Delprete, 1999; R. standleyana, det. J.-J. de Granville, 1975, conf. J.A. Steyermark, 1980], P05194637 [R. cornifolia (Kunth) Standl. 1931, det. D. Zappi, 10/2006; R. cf. standleyana, det. J.-J. de Granville, 1975, conf. J.A. Steyermark, 1980]).
Guyane française, monts Galbao, à 10 km WSW de Saül, forêt sur sommet, 650 m, 14/03/1973, jeunes fruits. Arbuste 0,5-1 m. Fruits ovoïdes, charnus, vert pâle. J.-J. de Granville 1536 (PT: CAY079066, CAY079067 [R. standleyana, det. J.A. Steyerm. 1975; R. cf. standleyana, det. J.H. Kirkbride, 1974], P05194568 [R. cf. standleyana, det. J.H. Kirkbride, 1973]).
Guyane française, mont Galbao, secteur Sud, 3°35’N, 53°20’W, 600 m, 22/01/1986, jeunes fruits. J.-J. de Granville, C. Feuillet, L. Hollenberg, O. Poncy & H. Sangray 8912 (PT: CAY007546 [R. sp.B, det. P.G. Delprete, 1999; R. sandemannii Sandwith 1949, det. C.M. Taylor, 1994], MO-2365256 [Rudgea sp.A, det. D. Zappi, 2009], NY).
Guyane française, mont Galbao, secteur Sud, 3°35’N, 53°20’W, 730 m, 27/01/1986, jeunes fruits. J.-J. de Granville, C. Feuillet, L. Hollenberg, O. Poncy & H. Sangray 9002 (PT: CAY077730 [R. sp.B, det. O. Lachenaud, 2014; R. sandemannii Sandwith 1949, det. C.M. Taylor, 1994], MO-2365257 [Rudgea sp.A, det. D. Zappi, 2009]).

Type : Guyane française, montagne Bellevue de l’Inini, extrémité SW, versant NW, 650 m, 15/08/1985, fruits. J.-J. de Granville, L. Allorge, G. Cremers, A.R.A. Görts-van Rijn & J.F. Kodjoed 7525 (PT: CAY079070 [R. standleyana, det. F. Crozier, 1999]).
Guyane française, montagne Bellevue de l’Inini, zone orientale, versant sous le vent, 600 m, 28/08/1985, fruits. J.-J. de Granville, L. Allorge, G. Cremers, A.R.A. Görts-van Rijn & J.F. Kodjoed 7858 (PT: CAY079072 [R. standleyana, det. F. Crozier, 2000]).
Guyane française, montagne Bellevue de l’Inini, zone centrale, 700 m, 08/09/1985, fruits. J.-J. de Granville, L. Allorge, G. Cremers, A.R.A. Görts-van Rijn & J.F. Kodjoed 8109 (PT: CAY079071 [R. standleyana, det. F. Crozier, 2000], MO-1505381 [Rudgea sp., det. C.M. Taylor, 2016; Coussarea violacea Aubl. 1775, det. C.M. Taylor, 1994]], P).
Guyane française, Tumuc Humac, forêt dense sur la crête du Mitaraka sud, à 1,5 km environ à l’ouest du sommet, 650 m, 17/08/1972, fruits. J.-J. de Granville 1280 (PT: CAY079064, CAY079065 [R. cf. standleyana, det. J.-J. de Granville, 1975]).
Suriname, Tumuc Humac Mts, Talouakem, 2°31’N, 54°45’W, 480 m, 09/08/1993, fruits. P. Acevedo-Rodriguez, J.-J. de Granville, L. Hollenberg, A. Joly & C. Avril 5969 (PT: CAY079178, US).
Suriname, Tumuc Humac, frontière Brésil-Suriname, brousse et forêt basse sur le sommet du Paloulouiméenpeu, 700 m, 02/08/1972, fruits. J.-J. de Granville 1087 (PT: CAY079062, CAY079063 [R. cf. standleyana, det. J.A. Steyermark, 1975]).
Brésil, Amazonas. Mun. Presidente Figueiredo, Reserva Biologica Uatumã, grade do PPBio, Baixio, 10/07/2008, fruits. J.F. Stancik, S. Sakagawa, M.S. Tavares, R.L. da Silva & F.C. Costa 449 (PT: K000771422).