Distribution : Endémique des highlands du Guyana (Mt. Ayanganna et environs, 1100-1650 m). Lachenaud
et al. (Phytotaxa, 531(3):
158-159. 21/01/2022) indiquent que le paratype appartient en fait à
Rudgea graciliflora Standl. 1936*, et qu'en dehors de l'holotype une seule collecte est connue**.
* "The two collections cited in the protologue of this species, the flowering type Tillett
et al. 45182 and the fruiting paratype Tillett
et al. 45023 (K, NY), are not conspecific. The former has stipules without a dorsal keel (the appendages are inserted directly on the sheath), leaves with prominently reticulate tertiary veins, and inflorescences with the lateral flowers of a triad pedicellate. The latter has stipules with a dorsal keel exceeding the sheath, tertiary leaf veins hardly apparent, and sessile fruits; it appears to represent
Rudgea graciliflora Standley (1936: 262) sensu lato, although its secondary leaf veins are more numerous (9-11 pairs) than usual for this species (5-8 pairs). Steyermark’s (1967) description is consequently based on a mixture (the details of the fruits, in particular, do not apply to
R. ayangannensis) and a new description is presented here. Apart from the type, only one collection has been seen that represents true
R. ayangannensis."
** Guyana, Pakaraima Mountains, Mount Wokomung, summit ridge of Ka-mie-wah
pinnacle NE to S pinnacle, "Little Ayanganna", 05°04’N 59°52’W, mixed hardwood cloud forest grading to Guyanan scrub forest on pinnacular escarpments, on sandstone, 1550-1650 m, 17 /11/1993, jeunes fruits. Tree 3 m. Fruit yellowish-green, subglobose, 0,75 cm diam . T. Henkel, R. Williams, S. Fratello & L.
Williams 4471 (K,
P00983456).
Taxonomie : D'après Lachenaud
et al. (Phytotaxa, 531(3):
158-159. 21/01/2022): "The species remains poorly known; no mature fruits have been seen, and it is not known whether its flowers are heterostylous (the only ones seen, on the type, have an included style). […]
Rudgea ayangannensis may be confused with both
R. graciliflora, from which, in addition to the characters discussed above, it also differs in its much shorter corolla tube, and
R. graniticola; for differences with the latter, see that species."
Type : Guyana, Mt. Ayanganna (haute Mazaruni), mixed evergreen forest between first and second cliffs along northeast side, 900-1100 m, 07/08/1960, fleurs. Bushy shrub to 2 m, leaves stiff, brittle, dark green above, lighter beneath, flowers pure white. S.S. Tillett, C.L. Tillett & R. Boyan 45182 (HT:
NY00133206).
Guyana, Mt. Ayanganna (haute Mazaruni), on laterite below talus of cliffs, along northeast side, 762 m, 03 & 05/08/1960, fruits. Small tree to 8 m, 1,5 dm base diam, leaves more or less brittle, dark green above,
lighter beneath, fruits bright orange-red, becoming red at maturity. S.S. Tillett, C.L. Tillett & R.
Boyan 45023 (PT:
L, NY [
Rudgea graciliflora Standl. 1936, fide Lachenaud
et al., Phytotaxa, 531(3):
158-159. 21/01/2022],
RB00543700,
US00643294).
