Eperua schomburgkiana Bentham (1870: 226)

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 : 92-94

18. Eperua schomburgkiana Bentham (1870: 226)

( Figures 8 , 53 )

Type (designated by Cowan 1975 / Fortes & Mansano 2022): — GUYANA. Essequibo & Rupununy, 1838, Schomburgk Rob. Ser. 1 517 (lectotype K[000555112] image!, isolectotypes BM[000065064] image!, G[00365223] image!, G[00365208] image!, K[000555113] image!, K[000555114] image!, P[00252893] image!, W not seen).

Tree (3.0–)4.0–35.0 m tall. Trunk and bark not seen. Stipules (6.2–)10.3–30.0(–44.0) mm, free, foliaceous, persistent to caducous. Leaves (3–)4–7-jugate; petioles 1.0– 3.6 cm long; rachis (7.3–)10.0–23.5(–30.0) cm long; petiolules 5.2– 11.9 mm long; blades 5.9–18.5 × (1.7–) 2.7–7.2 cm, coriaceous, glabrous, pellucid-punctate, sometimes inconspicuous pellucid-punctate, discolorous to not discolorous, equilateral, lower pair elliptic, narrowly elliptic to ovate, rarely lanceolate, middle pair elliptic, narrowly elliptic to ovate, rarely lanceolate, upper pair elliptic to narrowly elliptic, apex attenuate, acuminate to caudate, base symmetrical to asymmetrical, lower pair base obtuse to rounded, sometimes subcordate, middle pair base obtuse to rounded, upper pair base obtuse to cuneate, margin flat, secondary venation with one intramarginal vein, sometimes two intramarginal veins, vein closer to the margin not continuous, main vein straight, prominent only near the base to entirely prominent on the adaxial surface, tertiary veins conspicuous, areoles smaller, concave. Inflorescences terminal, rarely axillary, panicle, rarely raceme, erect, tomentose, coppery, 4.0– 11.5 cm long, lateral racemes 1.9–7.2 cm long, alternate and distichous; bracts 4.1–5.9 × 3.4–5.6 mm, ovate, broadly ovate to orbicular, apex gland absent?, tomentose externally, coppery, caducous; bracteoles 4.5–6.3 × 3.0–5.0 mm, ovate, cucullate, apex gland absent, tomentose externally, coppery, caducous, attached to the middle portion of the pedicels; pedicel 10.8–26.2 mm long, 1.4–2.7 mm in diameter, not twisted, tomentose, copery; buds 1.0– 2.2 cm long, 0.5–1.0 cm in diameter, tomentose, coppery. Flowers: hypanthium 3.8–6.4 mm long, 4.7–7.3 mm in diameter, cup-shaped, equilateral, tomentose, coppery; sepal 1.6–2.6 × 0.4–1.7 cm, elliptic to oblong, unequal, the dorsal one larger, apex gland absent, tomentose externally, coppery, inner sepals scarious marginally; adaxial petal 2.0–3.2 × 2.9–5.0 cm, oblate, non-tubular, apex rounded, base truncate, white, glabrous; petalodia 1.1–1.8 × 1.1–1.6 mm; stamens exserted, joined basally in a diadelphous sheath, dorsal one free, longer filaments 3.0– 4.5 cm long, shorter filaments 2.9–3.5 cm long, sheath equilateral, 7.0–12.0 mm long, sheath irregularly tomentose on both sides to glabrous externally and entirely tomentose in the inner surface, free filaments glabrous, coppery, anthers 4.0–6.1 × 1.0– 2.2 mm, rectangular; ovary 6.0–15.0 × 2.4–5.0 mm, oblanceolate, glabrous, stipe 6.3–13.7 mm long, glabrous, style 2.2–3.7 cm long, stigma capitate, papillose. Legumes 12.0–23.0 × 4.0– 7.5 cm, stipe 1.3–2.0 cm long, oblanceolate-falcate, apex obtuse, apiculate, margin entire, brown to reddish brown, veins absent, glabrous, foveate. Seeds 1–3 per fruit, 3.5–5.0 × 1.8–3.6 cm, elliptic, oblong to irregularly oblong, brown to reddish-brown.

Phenology:— Flowering in March and from June to December, with a peak in September; fruiting throughout the year, except in June and August.

Distribution:— Throughout Guyana (Cuyuni-Mazaruni, East Berbice-Corentyne, Essequibo Islands-West Demerara, Macouria, Potaro-Siparuni, Upper Demerara-Berbice, Upper Takatu-Upper Essequibo) and in Surinam (Nickerie, Sipaliwini).

Habitat:— Mainly in floodplain forests (e.g. Mora forests and swamps), sometimes in wallaba forests, on alluvial soil, predominately white sand, but also brown sand mixed, loamy and laterite soils, from sea level to 130 m elev.

Conservation status:— Categorized as Least Concern (LC) according to the IUCN criteria ( IUCN 2012, IUCN Standards and Petitions Committee 2022). The estimated extent of occurrence for the species is 61,910.701 km 2 and the estimated area of occupancy is 156.000 km 2.

Occurrence in protected areas:— Iwokrama Rainforest Reserve ( Guyana, Potaro-Siparuni) and Conservation International concession on the Essequibo River ( Guyana, Upper Takatu-Upper Essequibo).

Etymology:— The specific epithet is a tribute to Schomburgk, who first collected the species in Guyana ( Bentham 1870).

Vernacular names:— bimiti wallaba (Mori S.A. et al. 8162), clump wallaba (Redden K.M. et al. 6011), cutlass (Redden K.M. et al. 3258, 3272), ituri wallaba (Mori S.A. et al. 8162), machetta (Mori S.A. et al. 8162), maseta (Redden K.M. et al. 3258), museta (Redden K.M. et al. 3272), wallaba (Anderson C.W. 182), water wallaba (Mori S.A. et al. 8162, Pennington R.T. 373, Persuad A.C. 14, 166, 183, Schulz J.P. 7708).

Uses:— unknown.

Taxonomic notes:— Eperua schomburgkiana , E. cerradoensis , E. duckeana , E. froesii , and E. reddeniae are the only short and erect inflorescence species that have non-tubular corolla, exserted stamens, falcate fruit with a 3:1 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. Similarities and differences between species of this group are summarized in Table 3 . Eperua schomburgkiana is a well-differentiated species by the stamens joined basally in a sheath 9+1, irregularly tomentose sheath, glabrous ovary and fruits, besides other vegetative characteristics (see Table 3 ).

Selected specimens:— GUYANA. Cuyuni-Mazaruni, Bartica, Moorie island in the Essequibo River near Bartica , 5–25 m elev., 18 August 1976, Mori S. A . et al. 8162 ( U, US); Essequibo River, Moraballi Creek, near Bartica, 28August 1929, Sandwith N. Y . 142 (RB, P, U, US). W bank of Essequibo River 0–2 km south of Wolga settlement, 0–15 m elev., 6°27’0”N 58°37’59”W, 24 December 1992, Henkel T. W . & Chin M . 669 ( U, US); Marshall Falls, Mazaruni River, 37 m elev., 6°17’5.6”N 58°43’15.5”W, 06 March 2004, Redden K. M . et al. 2115 ( US). East Berbice - Corentyne, Canje River, Cow Savanna E of Digitima Creek , 1–25 m elev., 5°36’0”N 57°35’0”W, 12 April 1987, Pipoly J. J . et al. 11448 (CAY, MO, U, US). Essequibo Islands-West Demerara, Esequibo, along bank of river, 7.5 km. from Lanaballi, 1–10 m elev., 6°60’0”N 57°75’0”W, 10 September 1992, Tiwari S . 851 (NY). Potaro-Siparuni, Iwokrama Forest Reserve, Burro-Burro River, 3.42 miles from Whitewater base camp, 65 m elev., 4°40’58”N 58°50’47.3”W, 02 November 2002, Redden K. M . et al. 1142 ( US); Micobe Road and adjacent forest next to Potaro River, 22 m elev., 5°20’29”N 58°58’51”W, 14 September 2006, Redden K. M . et al. 4231 (NY, US). Upper Demerara-Berbice, Lower 3 km of Macouria River , N and S banks, 15 m elev., 6°25’0”N 58°34’0”W, 07 December 1992, Henkel T. W . & Chin M . 388 ( U, US); Essequibo River , E bank, upstream 2–4 km from Bartica, island shore and mainland, 0–5 m elev., 6°25’0”N 58°35’0”W, 31 March 1993, Henkel T. W . et al. 1798 (US); CI concession, Himara Creek, 130 m elev., 3°22’0”N 58°11’0”W, 14 September 2008, Redden K. M . et al. 6011 (US). Upper Takatu-Upper Essequibo, Conservation International concession on the Essequibo River, 108 m elev., 3°35’18”N 58°17’58”W, 21 January 2007, Redden K. M . et al. 5138 ( F, NY, U, US). Essequibo & Rupununy, 1838, Schomburgk Rob. Ser. I 517 ( BM, G, K, P, W) . SURINAM. Nickerie, Corantijn , ten N . mondingen New River, 01 September 1935, Rombouts H. E . 170 (U). Sipaliwini, Wonatobo falls, Corantijn River, 26 June 1956, Schulz J. P . 7708 (U, US).

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 53. Eperua schomburgkiana: A. habitat; B. pellucid-punctate leaflet blade; C. intramarginal vein, abaxial surface; D. inflorescence; E. detail of the inflorescence indumentum; F. flower, lateral view; G. flower, front view. Specimens, B, C: Anderson C.W. 182; E: Sandwith N.Y. 142. Photos, A, D, F, G: H. ter Steege; B, C, E: E.A. Fortes.