Eperua duckeana R.S. Cowan (1975: 30)

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 : 32-35

4. Eperua duckeana R.S. Cowan (1975: 30)

( Figures 8 , 19 , 20 )

Type : — BRAZIL. Amazonas : Rio Urubú abaixo da cachoeira Iracema, 7 July 1941, Ducke W. A. 732 (holotype US[00001144]!, isotypes F [0057800] image!, IAN [010263]!, MG [017957]!, MO [954041] image!, NY [1171178] image!, R sheet I [000054531]!, & sheet II[000054531a]!, SI [002003] image!) .

Tree 3.5–35.0 m tall. Trunk 5.0–60.0 cm in diameter, bark brownish, reddish-brown to grayish-brown, smooth to striate, lenticellate. Stipules 5.3–38.7 × (1.3–) 3.4–26.9 mm, free, foliaceous, caducous to persistent. Leaves 3–5-jugate; petioles 0.6–2.9 cm long; rachis (3.7–)6.8–19.5(–24.0) cm long; petiolules 3.6–10.4 mm long; blades 4.7–14.7 × 2.0– 10.3 cm, coriaceous, glabrous, pellucid-punctate, rarely inconspicuous pellucid-punctate, discolorous, sometimes slightly discolorous, equilateral, lower pair elliptic, sometimes lanceolate, rarely ovate or broadly elliptic, middle pair elliptic, sometimes lanceolate, rarely narrowly elliptic, upper pair elliptic, rarely lanceolate, obovate, or narrowly elliptic, apex attenuate to acuminate, mucronate, base asymmetrical, rarely oblique, lower pair base cuneate, obtuse, rounded to subcordate, middle pair base obtuse to rounded, sometimes cuneate to subcordate, rarely cordate, upper pair base obtuse to cuneate, margin flat, secondary venation with two intramarginal veins, sometimes one, vein closer to the margin not continuous, main vein straight, very prominent on the adaxial surface, tertiary veins conspicuous, areoles smaller, concave. Inflorescences terminal, rarely axillary or on the branchlets, panicle, sometimes raceme, erect, tomentose, brownish-yellow, 6.0–20.0 cm long, lateral racemes 2.3–18.0 cm long, alternate and distichous; bracts caducous, not seen; bracteoles 1.9–5.0 × 2.3–4.2 mm, ovate, rarely semiorbicular, cucullate, apex gland absent, tomentose externally, glabrous within, brownish-yellow, falling early, attached to the lower middle portion of the pedicels; pedicel 15.0– 23.3 mm long, 1.0– 2.8 mm in diameter, not twisted, tomentose to pubescent, brownish-yellow or coppery; buds 0.8–1.8 cm long, 0.4–0.9 cm in diameter, tomentose, brownish-yellow. Flowers: hypanthium 3.3– 10.6 mm long, 2.9–7.4 mm in diameter, cup-shaped, sometimes tubular, equilateral, tomentose, brownish-yellow; sepal 0.8–1.9 × 0.3–0.9 cm, elliptic, sometimes oblong or ovate, unequal, the outer ones larger, cucullate, apex gland absent, greenish, green, greenish with rose spots, white to cream, tomentose externally, brownish-yellow, inner sepals scarious marginally; adaxial petal 1.2–2.4 × 1.9–3.3 cm, oblate, non-tubular, apex truncate or rounded, base truncate, white, whitish, greenish, cream to white-lilac, glabrous; petalodia 0.4–1.6 × 0.4–1.0 mm; stamens, exserted, joined basally in a diadelphous sheath, dorsal one free, longer filaments 1.7–4.9 cm long, shorter filaments 1.2–3.4 cm long, sheath slightly inequilateral to equilateral, shorter side 3.0– 8.1 mm long, longer side 6.1–8.7 mm long, sheath entirely tomentose, free filaments glabrous, brownish-yellow, shorter stamens anthers 2.7 × 0.7 mm, rectangular, longer stamens anthers 2.2–4.1 × 0.7–1.3 mm, rectangular; ovary 5.9–9.9 × 1.8–4.5 mm, oblaceolate, tomentose, brownish-yellow, stipe 2.9–9.1 mm long, tomentose, style 2.7–4.3 cm long, stigma obtuse to capitate. Legumes 7.5– 22.0 × (1.3–)4.0– 8.4 cm, stipe 1.1–2.5 cm long, with remnants of the androecium, oblanceolate-falcate, apex obtuse, sometimes acute, apiculate, margin entire, dull brown, veins absent, sometimes with inconspicuous transversal veins, tomentulose, rarely tomentose or tomentulose to glabrescent with long scattered trichomes, brownish-yellow. Seeds 2–4 per fruit, 3.1–4.5 × 1.7–3.0 cm, ovate to oblong, reddish-brown.

Phenology:— Flowering in March and from May to December with a peak from August to September; fruiting from January to March and from May to December with a peak in August.

Distribution:— Brazil in the states of Amazonas and Pará.

Habitat:— Mainly terra-firme forest, sometimes in igapó and várzea forests, and campinaranas, on sandy and clayey soil, from 7 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 estimated extent of occurrence for the species is 88,736.968 km 2 and the estimated area of occupancy is 204.000 km 2.

Occurrence in protected areas:— Reserva Florestal Adolpho Ducke ( Brazil, Amazonas).

Etymology:— The specific epithet is a tribute to Adolpho Ducke, who revised and described new species and varieties for the genus Eperua ( Ducke 1932, 1940, Cowan 1975).

Vernacular names:— envira iodo (Marra D.M. & Neves A.F. 78), muirapiranga branca (Coelho D. s.n. INPA 20747, Rodrigues W.A. & Chagas J. 1725, Rodrigues W.A. & Osmarino 6769), muirapiranga da folha miúda (Rodrigues W.A. & Chagas J. 1725, Rodrigues W.A. & Lima J. 2233, Rodrigues W.A. & Osmarino 6769), murajiboia (Mello F.C. de & Ribamar s.n. INPA 58309), pau de óleo (Silva S.F. da 205a).

Uses:— Used in constructions due to its heavy, soft, and resinous wood (Rodrigues W.A. & Chagas J. 1725).

Taxonomic notes:— Eperua duckeana , E. froesii , E. cerradoensis , E. reddeniae , and E. schomburgkiana are the only species with short and erect inflorescence that exhibit a non-tubular corolla, exserted stamens, falcate fruit with a length-to-width ratio of 3:1 (vs. tubular corolla, included stamens, non-falcate fruit with a length-to-width ratio of 1:1 to 2: 1 in other short and erect inflorescence species). They also share multijugate leaves with straight leaflets and inflorescence covered in dense indumentum. Furthermore, E. duckeana stands out as a distinct species due to its stamens fused at the base in a sheath of 9+1, tomentose sheath and ovary, and tomentulose fruits. These features and other vegetative characteristics contribute to its differentiation from other species. Additionally, E. duckeana has a specific distribution in the Central Amazonia region. Please refer to Table 3 for a summary of the similarities and differences among these species.

Selected specimens:— BRAZIL. Amazonas, Itapiranga, rio Pitinga, margem direita, 24 August 1979, Cid-Ferreira C.A. et al. 703 ( INPA, NY, US ). Manaus, Reserva Florestal Adolpho Ducke,, L4 após km 3350, 129 m elev., 2°56’59”S 59°56’10”W, 21 January 2022, Fortes E.A. et al. 190b ( INPA, RB, UEC, US ); Reserva Florestal Adolpho Ducke, Igarapé Ipiranga, pique do INPA , sentido oeste-leste, 2°53’0”S 59°58’0”W, 05 July 1993, Ribeiro J.E.L.S. et al. 1037 (HUEFS, INPA , K, MO, NY, R, RB, SP, U); ZF3, Distrito Agropecuário da SUFRAMA, rodovia BR 174, Km 64, depois 34 Km Leste na ZF3, fazenda Esteio, reserva nº 1302, árvore nº 775, 2°26’0”S 59°48’0”W, 24 September 1981, Nascimento J.R.M. et al. 1302.775 ( INPA, NY ); IFAM, Campus Manaus-Zona Leste, 05 November 2011, Kinupp V.F. et al. 4542 (EAFM). Presidente Figueiredo, no entorno do Lago da Rebio Uatum„, Balbina, 13 August 2008, Silva M.C.R. da et al. 40 ( INPA ). S„o Sebasti„o do Uatum„, RDS Uatum„, Igapó de topografia alta, situado nas margens do rio Abacate, 7 m elev., 2°11’37’’S 58°43’10’’W, 15 May 2016, Lobo G.S. 14 ( INPA ). Pará, Oriximiná, cachoeira da Porteira, entrada Perimetral Norte, 1°3’17.4”S 57°2’28”W, 09 June 2000, Faria S.M. de et al. 2053 (HSTM, RB); Porto Trombetas, rio Mapuera, cachoeira da Égua, Ilha, 11 December 1907, Ducke W.A. 9088 (RB). Rio de Janeiro (cultivated), Seropédica, Embrapa-Agrobiologia, 14 September 2001, Faria S.M. de & C. C.F. da 2186 (RB).

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 19. Eperua duckeana: A. bark; B. sap-wood and heartwood; C. leaves; D. detail prominent main vein on the adaxial surface; E. foliaceous stipules; F. fruits; G. intramarginal veins; H. pellucid-punctate leaflet; I. inflorescence; J. seed. Specimens, A–H, J: Fortes E.A. et al. 191b. Photos, A, B, F–H, J: E.A. Fortes; C: M. Pastore; D, E: F. Farroñay; I: H. ter Steege.

FIGURE 20. Eperua duckeana:A. flowering branchlet; B. adaxial petal; C. carpel with tomentose ovary and stipe, glabrous style, capitate stigma; D. tomentose hypanthium and pedicel, stamens joined in a diadelphous sheath 9+1, tomentose sheath, free filaments glabrous; E. anther and part of the filament. Specimen, A–E: Ducke W.A. 732. Illustrated by Carlos Alvarez.