Eperua glabra R.S. Cowan (1957: 251)

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 : 45-50

7. Eperua glabra R.S. Cowan (1957: 251)

( Figures 12 , 26 , 28 )

Type: — GUYANA. Near Chodikar Landing, Amongst Acarai foothills, 250 m elev., 17 October 1952, Guppy N. G. L. 430 (holotype NY sheet I [00004378] image!, & sheet II[00004379] image!; isotypes K sheet I [000555111] image!, & sheet II[000555109] image!, RB sheet I [00539601]!, sheet II[00545384]!, US [00001145]!) .

= Eperua praesagata R.S. Cowan. (1985: 293) syn. nov.

Type: — BRAZIL: Pará: Rio Trombetas , Cachoeira Porteira, estrada que dá acesso para Perimetral Norte, km 7, mata de várzea de igarapé, 8 June 1978, Silva N. T. & Santos M. R. 4758 (holotype MG [061723]!, isotypes MO [1714824] image!, NY [00004377] image!, RB [00141558]!, US [00090950]!) .

Tree 7.0–37.0(–51.0) m tall. Trunk 20.0–60.0 cm in diameter, bark variegated to grey-brown, striate, lenticellate. Stipules free, 10.3–25.0(–30.0) × 6.9–14.0(–20.0) mm, foliaceous, or 0.8–1.4 × 0.4–0.8 mm, free, non-foliaceous, caducous. Leaves 3–5-jugate; petioles 0.8–4.2 cm long; rachis 6.4–19.0 cm long; petiolules (1.3–) 3.7–9.1 mm long; blades 6.0–15.1 × 2.6–7.8 cm, chartaceous to coriaceous, glabrous, epunctate to inconspicuous pellucid-punctate, discolorous, equilateral to inequilateral, lower pair ovate, sometimes lanceolate or elliptic, middle pair ovate to elliptic, sometimes lanceolate, upper pair elliptic, apex acuminate to caudate, base symmetrical to asymmetrical, sometimes slightly asymmetrical, lower pair base subcordate, obtuse, subcordate to rounded, middle pair base obtuse to rounded, upper pair base obtuse to cuneate, rare rounded, margin flat, secondary venation with one or two intramarginal veins, vein closer to the margin continuous or not, main vein straight to slightly curved, prominent to depressed on the adaxial surface, tertiary veins conspicuous to inconspicuous, areoles smaller to larger, concave. Inflorescences terminal, panicle, main axis pendulous, lateral racemes patent to erect, glabrous, 93.0–300.0 cm long, lateral racemes 1.7–5.2 cm long, alternate and spirally arranged; bracts 0.9–1.9 × 2.2–2.3 mm, oblate, cucullate, apex gland absent, glabrous, ciliate, caducous; bracteoles 2.3–2.9 × 1.4–2.5 mm, ovate, cucullate, apex gland absent, ciliate, caducous, attached to the lower portion of the pedicels; pedicel 16.7–27.0 mm long, 1.0– 2.4 mm in diameter, not twisted, glabrous; buds 0.7–1.1 cm long, 0.4–0.6 cm in diameter, glabrous. Flowers: hypanthium 4.5–7.3 mm long, 3.5–7.8 mm in diameter, cup-shaped to tubular, equilateral, glabrous; sepal 1.1–2.2 × 0.5–1.2 cm, elliptic to oblong, unequal, the outer ones larger, cucullate, apex gland absent, purplish-green, glabrous; adaxial petal 1.5–3.0 × 2.2–5.0 cm, flabellate, non-tubular, apex rounded, base truncate, red, rose, pink to cream at base, cream to greenish at the base and pink marginally, glabrous; petalodia 0.5–1.6 × 0.4–0.9 mm; stamens exserted, joined basally in a tube, longer filaments 5.0– 7.8 cm long, shorter filaments 2.3–4.0 cm long, tube equilateral to slightly inequilateral, 2.1–3.8 mm long, anthers 5.0–9.0 × 0.7–2.0 mm, rectangular; ovary 5.2–12.5 × 2.2–3.5 mm, oblanceolate, glabrous, 5 ovules, stipe 5.5–10.9 mm long, glabrous, style 4.2–6.0 cm long, stigma capitate to obtuse. Legumes 17.0–30.5 × 4.8–10.0 cm, stipe 2.1–4.6 cm long, falcate-elliptic to falcate-oblanceolate, apex obtuse, apiculate, margin thickened, sometimes dorsal margin alate, with transversal veins or veins absent, glabrous, dark-brown to reddish-brown. Seeds 4 per fruit, 4.6–5.8 × 2.3–2.6 cm, oblate, oblong, dark-brown.

Phenology:— Flowering in February, May to July, September, and October; fruiting in January, May, and from September to November.

Distribution:— Brazil (Pará and Roraima), Guyana (Upper Takatu-Upper Essequibo, East Berbice-Corentyne, and Upper Demerara-Berbice). One sterile collection made further in Surinam (Oldenburger F.H.F. et al. 1203) was sampled in the full ribosomal phylogeny for the genus ( ter Steege et al. 2023 in press) and was nested within Eperua glabra specimens. It resembles E. glabra by the vegetative characteristics, but fertile collections are needed in Surinam to morphologically confirm the presence of the species in this country.

Habitat:— Upland (terra-firme) and inundated (gallery, and igapó) forests on clayey, brown and white mixed sandy, and brown sandy soils, from 200 to 250 m elev.

Conservation status:— Categorized as Least Concern (LC) according to the IUCN criteria ( IUCN 2012, IUCN Standards and Petitions Committee 2022). The occurrence extent of estimated for the species is 316,238.548 km 2 and the estimated area of occupancy is 40.000 km 2.

Occurrence in protected areas:— Parque Nacional Montanhas do Tumucumaque ( Brazil), Mabura Hill Forest Reserve ( Guyana, Upper Demerara-Berbice).

Etymology:— The specific epithet relates to its entirely glabrous inflorescences and flowers.

Vernacular names:— Brazil: espadeiro (Rodrigues I.A. et al. 1000). Guyana: wallaba (Redden K.M. et al. 1054) [although it is more often used to refer to E. falcata ], wataba (Redden K.M. et al. 1054), wataja ( Guppy N.G. L. 430).

Uses:— Unknown.

Taxonomic notes:— Eperua glabra and E. praesagata were described by Cowan (1957, 1985, respectively). These are the only entirely glabrous species within Eperua . They have long and pendulous inflorescence, non-tubular corolla, and exserted stamens, and share multijugate leaves with equilateral leaflets with E. rubiginosa .

In Cowan`s (1985) diagnosis of E. praesagata , its differentiation from E. glabra was based mainly on organ sizes (including filaments, anthers, stipules, and petioles sizes), besides the number of leaflets, and petal colour (see Table 5 ), but the key characteristics in the genus that allow to differentiate species are related to organ indumentum and bracteole position. Moreover, the organ size variations and leaflets number are not sufficient for distinguishing between the two species, particularly due to the limited number of collections available. Apart from the holotypes of both species, there are three additional flowering collections with entirely glabrous inflorescences and flowers. However, it is not possible to confirm if it is E. praesagata or E. glabra because these new collections have overlapping characteristics between both species (see Table 5 ). There are seven fruiting collections (including the type collection of E. glabra , and one paratype of E. praesagata ) with glabrous fruits in glabrous, long, and pendulous inflorescences. Still we did not recognize a pattern that allows us to separate them into two species.

The type locality of E. glabra is the Acarai Mountains on the Brazil-Guyana border, while the type locality of E. praesagata is in the Trombetas River in Oriximiná, Pará, Brazil (see Figure 12 ). Indeed, Cowan (1985, pg. 293) reported that the type locality of E. glabra is at a “relatively short distance north of the type locality” of E. praesagata . Subsequent collections of entirely glabrous specimens were made in various locations, including at the type locality of E. glabra , in the Acari Mountains and Chokidar river (Henkel T.W. et al. 4655, Redden K.M. et al. 3187, 3192, Smith A.C. 2882); further North from Brazil / Guyana border in the Mabura Hill Forest Reserve region (Polak A.M. 218, Redden K.M. et al. 1054); also, in Marapi River near the type locality of E. praesagata (Pena B.S. 499,); and one collection further West in Roraima state ( Brazil), but also near the border between Guyana and Brazil (Rodrigues I.A. et al. 1000). These two species are indeed sympatric and occupy the same habitat. Collections were made in upland (terra-firme) and inundated (várzea, gallery) forests in the Acarai Mountains and the Chokidar river. The holotype of E. praesagata (Silva N.T. & Santos M.R. 4758) was collected in inundated forests, but the paratype (Cid-Ferreira C.A. et al. 1419) is from upland forests. In conclusion, there is no reason to keep E. praesagata as a different species from E. glabra : their morphology overlaps, as well as their distributions and habitat; and they appeared paraphyletic in the phylogeny when considered different taxa ( ter Steege et al. 2023 in press, Fortes et al. in prep.,). For all these reasons, they are synonymized here.

There is one collection, Silva F.A. et al. 869 (MG[245424]!), from Januari River in the Estaç„o Ecológica Gr„o- Pará, Roraima, Brazil, which bears a resemblance to E. glabra by the long and pendulous inflorescence with glabrous main axis, and glabrous stamens and ovary. However, it differs from E. glabra by its puberulent lateral racemes and bracts, puberulous bracteoles, pedicel, buds, and hypanthium, and puberulent to glabrescent sepals ( Figure 27 ). Phylogenetically, this collection is nested within E. glabra (Fortes et al. in prep.). Further collections and studies are needed to determine this collection’s taxonomic rank.

Selected specimens:— BRAZIL. Pará, Oriximiná, rio Trombetas , Tapagem, margem direita a 15 Km acima da mineraç„o Santa Patrícia, 09 July 1980, Cid-Ferreira C.A. et al. 1419 ( EAFM, INPA, MG, MO, NY, RB, US ); Distrito de Marapi, rio Marapi , ponto 32, 07 September 1974, Pena B.S. 499 ( IAN). Roraima, S „o Jo„o da Baliza , BR 210 , Km 135, a 6Km do rio Jatapú, lado esquerdo , 0°44’14”N 59°15’15”W, 16 January 1983, Rodrigues I.A. et al. 1000 ( IAN). GUYANA. Upper Demerara-Berbice, Waraputa compartment , c. 25 km S of Mabura, 5°15’0”N 58°45’0”W, 09 January 1991, Polak A.M. 218 ( U); Mabura Hill Forest Reserve , 5°9’33.8”N 58°41’51.8”W, 20 October 2002, Redden K.M. et al. 1054 ( U, US). Upper Takatu-Upper Essequibo, Acarai Mts, Watuwau Creek 8–10 km upstream of juncture with Chodikar River, 1°22’0”N 58°42’0”W, 22 February 1994, Henkel T.W. et al. 4655 ( CAY, U, US); Chodikar River , 239 m elev., 1°23’39.3”N 58°47’7.5”W, 04 May 2004, Redden K.M. et al. 3187 ( NY, US); Chodikar River , 243 m elev., 1°24’53.3”N 58°47’43.2”W, 04 May 2004, Redden K.M. et al. 3192 ( US); basin of Chodikar Creek ( Essequibo tributary), 1°18’0”N 58°49’59”W, 8–22 January 1938, Smith A.C. 2882 ( F, P, U, US).

Figures

FIGURE 12. Geographic distribution of Eperua glabra, E. rubuginosa var rubiginosa, and E. rubiginosa var. grandiflora.

FIGURE 26. Eperua glabra: A. glabrous inflorescence; B. detail of a young lateral raceme in buds showing ciliate bracts and bracteoles. Specimens, A, B: Redden K.M. et al. 3192; E: Henkel T.W. et al. 4655. Photos, A, B, E: E.A. Fortes; C, D: H. ter Steege.

FIGURE 27. Eperua aff. glabra: A. flowering branchlet and a young fruit; B. inflorescence indumentum. Specimen, Silva F.A. et al. 869. Photos, E.A. Fortes.

FIGURE 28. Eperua glabra: fruiting branchlet showing the erect lateral racemes. Specimen, Guppy N.G.L. 430 (holotype of E. glabra). Illustrated by Carlos Alvarez.