Eperua reddeniae, E.A. Fortes & Mansano, 2023

Fortes, Elenice A., Dos, Ilka P., Steege, Hans Ter, Aymard, Gerardo, Secco, Ricardo De S., Martins-Da-Silva, Regina Célia V. & Mansano, Vidal F., 2023, A taxonomic revision of the genus Eperua (Leguminosae, Detarioideae, Detarieae), Phytotaxa 617 (1), pp. 1-127 : 83-84

16. Eperua reddeniae E.A. Fortes & Mansano, sp. nov.

( Figures 8 , 48 , 49 , 50 )

Type:— GUYANA. Cuyuni-Mazaruni, Mazaruni River , small islands along river, 90 m elev., 6°0’12.6”N 59°13’28.9”W, 11 October 2004, Redden K. M. et al. 3274 (holotype US [00808373]!, isotypes CAY [109816, 109817] image!, INPA [0220628]!)

Diagnosis: — Eperua reddeniae has short and erect inflorescences, non-tubular corollas, and exserted stamens. It differs from species with the same type of inflorescence, corolla, and stamen by the combination (see Table 3 ): stipules joined at the base, inconspicuous pellucid punctate to epunctate leaflets, slightly revolute margins, coppery inflorescence indumentum, pink to purple petals, stamens joined basally in a diadelphous sheath, dorsal one free, sheath irregularly tomentose in the middle-high portion and glabrous at the base, tomentose ovary, tomentulose fruits with entire margins.

Tree 8–20.0 m tall. Trunk 20.0 cm in diameter, bark not seen. Stipules 10.9–19.2 × 6.3–12.2 mm, joined at the base, foliaceous, persistent. Leaves 4–5-jugate; petioles 1.0– 1.5 cm long; rachis 10.2–15.0 cm long; petiolules 6.2–8.2 mm long; blades 5.3–11.8 × 2.8–5.0 cm, coriaceous, glabrous, pellucid-punctate to epunctate, discolorous, equilateral, lower pair elliptic to ovate, middle pair elliptic, upper pair elliptic, apex attenuate to acuminate, mucronate, base symmetrical to asymmetrical, lower pair base subcordate to obtuse, middle pair base obtuse, upper pair base obtuse, margin flat to slightly revolute, secondary venation with two intramarginal veins, sometimes one, vein closer to the margin not continuous, main vein straight, prominent on the adaxial surface, tertiary veins conspicuous, areoles smaller, concave. Inflorescences terminal or axillary, panicle, erect, tomentose, coppery, 13.1–16.0 cm long, lateral racemes 2.1–11.8 cm long, alternate and distichous; bracts caducous, not seen; bracteoles 2.1–3.8 × 2.3–2.4 mm, ovate, cucullate, apex gland absent, tomentose on both sides, coppery, caducous, attached to the lower middle portion of the pedicels; pedicel 18.4–26.2 mm long, 1.3–2.1 mm in diameter, not twisted, tomentose, coppery; buds 1.1–1.5 cm long, 0.6–0.7 cm in diameter, tomentose, coppery. Flowers: hypanthium 4.3–6.3 mm long, 4.9–6.1 mm in diameter, cup-shaped, equilateral, tomentose, coppery; sepal 1.9–2.7 × 0.6–1.2 cm, elliptic to oblong, unequal, the outer ones larger, cucullate, apex gland absent, green, tomentose externally, coppery, inner sepals scarious marginally; adaxial petal 2.0–2.1 × 3.2–4.0 cm, oblate, non-tubular, apex rounded, base truncate, pink to purple, glabrous; petalodia 0.5–0.8 × 0.8–1.0 mm; stamens, exserted, joined basally in a diadelphous sheath, dorsal one free, longer filaments 4.2–5.0 cm long, shorter filaments 3.0 cm long, sheath equilateral, 5.2–8.0 mm long, sheath irregularly tomentose in the middle-high portion and glabrous at the base, free filaments glabrous, coppery, anthers 5.2–6.6 × 1.0– 1.5 mm, rectangular; ovary 9.2–12.0 × 4.0– 4.2 mm, oblaceolate, tomentose, cream (fresh) to coppery (dried), stipe 8.8–15.0 mm long, tomentose, style 3.5–5.0 cm long, stigma obtuse to capitate. Legumes 21.0 × 7.6 cm, stipe not seen, oblanceolate-falcate, apex acute, apiculate, margin entire, coppery, veins absent, tomentulose, coppery. Seeds, 4.3 × 2.6 cm, ovate to oblong.

Phenology:— Flowering in September and October.; fruiting in October

Distribution:— Guyana (Cuyuni-Mazaruni).

Distribution and habitat:— Floodplain (gallery) forests on mixed brown and white sand soils, at 63–90 m elev.

Conservation status:— Categorized as Data Deficient (DD) according to the IUCN criteria ( IUCN 2012, IUCN Standards and Petitions Committee 2022) as it is known by only two specimens.

Occurrence in protected areas:— Unknown.

Etymology:— The specific epithet is a tribute to Karen Redden, a botanist who studied Detarieae groups and the Guyana Shield Flora, besides collecting a lot of species of Eperua (over eighty specimens and 11 species), including the type specimen of this new species.

Vernacular names:— Described as having the common name “tricel” in the Redden K.M. et al. 3260 collection label. However, a similar name, “trysil”, is the vernacular name of the locally quite common species, Pentaclethra macroloba Kuntze , and likely the name “tricel” was mistakenly coined by the collectors (ter Steege pers. obs.)

Uses:— Unknown.

Taxonomic notes:— Eperua reddeniae , E. froesii , E. cerradoensis , E. duckeana and E. schomburgkiana are the only species with short and erect inflorescences that have non-tubular corolla, exserted stamens, falcate fruit with a 3:1 length/width proportion (vs. tubular corolla, included stamens, non-falcate fruit with a 1:1 to 2:1 length/width proportion in other short and erect inflorescence species). They also share multijugate leaves with straight leaflets and inflorescence with dense indumentum. Additionally, E. reddeniae shares caducous bracteoles and stamens joined in a diadelphous sheath 9+1 with E. duckeana and E. schomburgkiana ; and irregularly tomentose sheath with E. schomburgkiana . Similarities and differences between species of this group are summarized in Table 3 . The flower of E. reddeniae is most similar to E. duckeana by the non-glabrous sheath, ovary, and fruits, and the diadelphous stamen sheath. Besides the allopatric distribution ( E. reddeniae is restricted to Guyana, and E. duckeana to the Central Amazonia, Figure 8 ), E. reddeniae differs from E. duckeana mainly by the coppery inflorescence indumentum (vs. brownish-yellow in E. duckeana ), pink to purple petals (vs. white in E. duckeana ), and irregularly tomentose sheath (vs. entirely tomentose in E. duckeana ).

Specimens examined (Paratypes):— GUYANA. Cuyuni-Mazaruni, Mazaruni River, unnamed falls (possible Carin Crow Falls ), 0.26 miles NW of base camp, 63 m elev., 5°57’25”N 59°18’41.8”W, 09 September 2004, Redden K. M. et al. 3260 ( US [00889812]!).

Figures

FIGURE 8. Geographic distribution of Eperua species with short and erect inflorescence and non-tubular corolla: Eperua cerradoensis, E. duckeana, E. froesii, E. reddeniae, and E. schomburgkiana.

FIGURE 48. Eperua reddeniae: A. flowering branchlet; B., C. foliaceous stipules joined at the base; D. inconspicuous pellucid-punctate blade; E. intramarginal vein, abaxial surface; F. lateral raceme in buds; G. detail of the inflorescence indumentum. Specimen, A, B, D–G: Redden K.M. et al. 3260; C: Redden K.M. et al. 3274. Photos, E.A. Fortes.

FIGURE 49. Eperua reddeniae: A. flower in pre-anthesis and other showing the carpel and stamens (sepals and adaxial petal removed); B. fruit; C. pedicel showing the bracteoles scar (white arrow) on its middle portion; D. sepals; E. detail of the hypanthium, petalodia (white arrow), base of the stamens, and intrastaminal nectaries; F. bud showing the adaxial petal and part of the anthers (sepals removed); G. adaxial petal from a bud; H. anther and part of the filament; I. base of the stamens joined in a diadelphous sheath (free stamen on the left) and tomentose carpel. Specimens, Redden K.M. et al. 3274. Photos, E.A. Fortes.

FIGURE 50. Eperua reddeniae: A. fruiting branchlet; B. joined foliaceous stipules; C. detail of leaflet margin, abaxial side, showing the intramarginal vein; D. detail of a lateral raceme in buds; E. detail of the inflorescence axis indumentum; F. flower in pre-anthesis showing the bracteole scars at the middle portion of the pedicels; G–I. sepals; J. flower showing the stamens joined basally in a diadelphous sheath, the tomentose ovary, and one petalodia right above the hypanthium (sepals and adaxial petal removed); K. detail of the base of the stamens and one petalodia at the bottom right, the free stamen is at the middle, through the sheath aperture it is possible to see the intrastaminal nectaries; L. adaxial petal from a bud; M. anther and part of the filament. Specimens, A, C, D, E: Redden K.M. et al. 3260; B, E–N: young fruit. Illustrated by Marcus Falc„o.