5. Eperua falcata Aublet (1775: 369)

(Figures 11, 21, 22)

Type (designated by Cowan 1975): — FRENCH GUIANA. Cayenne, s.d. [July 1762 – July 1764], Aublet J. B. C. F. s.n. (lectotype BMinflorescence [000952284] image!) .

≡ Dimorpha falcata (Aubl.) Forsyth (1794: 391) nom. illeg. superfl.

≡ Panzera falcata (Aubl.) Willdenow (1799: 540), nom. illeg. superfl.

≡ Dimorpha falcata (Aubl.) Smith in Rees (1808: 656), nom. illeg. superfl.

Tree 8.0–40.0 m tall. Trunk 20.0–70.0 cm in diameter, bark grayish to reddish, smooth, lenticelate. Stipules 1.4–4.3 × 1.3–3.1 mm, joined, non-foliaceous, caducous to persistent. Leaves (2–)3–4-jugate; petioles 1.2–9.7 cm long; rachis 1.2–11.9 cm long; petiolules 2.5–6.5 mm long; blades 2.6–17.5 × 2.4–6.8 cm, chartaceous, sometimes coriaceous, glabrous, minutely pellucid-punctate, not all areoles have one dot, not discolorous to discolorous, inequilateral, all pairs elliptic-falcate, apex acuminate, sometimes caudate, mucronulate, base asymmetrical, lower pair base obtuse to rounded, middle pair base obtuse, rounded or cuneate, upper pair base obtuse to cuneate, rarely rounded, margin flat, rarely slightly revolute, secondary venation with one intramarginal vein very close to the margin, main vein curved, depressed, rarely prominent near the base on the adaxial surface, tertiary veins conspicuous, areoles larger, plane. Inflorescences terminal, rarely axillary, panicle, main axis and lateral racemes pendulous, main axis strigulose, sometimes glabrous, lateral racemes tomentose, brownish, 66.0–300.0 cm long, lateral racemes (1.1–)2.5–8.8(–11.0) cm long, alternate and spirally arranged; bracts 2.9–3.2 × 1.3–1.8 mm, ovate, apex gland absent, tomentose, brownish, caducous; bracteoles 2.3–6.1 × 2.3–4.0 mm, broadly ovate, sometimes ovate, apex gland absent, tomentose, brownish, caducous, attached to the higher portion of the pedicels; pedicel 8.3–19.3 mm long, 0.7–1.5 mm in diameter, twisted, tomentose, brownish; buds 0.8–1.8 cm long, 0.4–0.9 cm in diameter, tomentose, brownish. Flowers: hypanthium 3.6–5.3 mm long, 3.3–6.3 mm in diameter, cup-shaped, equilateral, tomentose, brownish; sepal 1.0–1.8 × 0.5–1.2 cm, elliptic to oblong, unequal, the outer ones larger, cucullate, apex gland absent, pink, red, redidish-green to greenish, tomentose, inner sepals scarious marginally, brownish; adaxial petal 1.0–2.0 × 1.2–2.5 cm, oblate, non-tubular, apex rounded, base truncate or subcordate, gibbous, pink, pale-pink, purple, reddish, greenish to red, glabrous; petalodia 0.5–1.9 × 0.7–1.2 mm; stamens exserted, joined basally in a diadelphous sheath, dorsal one free, longer filaments 3.7– 4.6 cm long, shorter filaments 1.5–2.4 cm long, sheath equilateral, 2.1–7.3 mm long, sheath and free filaments base villous, middle to upper free filaments glabrous, brownish, anthers 5.7–6.0 × 1.6–2.0 mm, rectangular; ovary 4.7–8.8 × 2.2–4.4 mm, oblong to obovate, sericeous, brownish, stipe 3.6–6.2 mm long, sericeous, style 2.2–4.5 cm long, stigma capitate. Legumes 19.0–38.0 × 5.1–10.8 cm, stipe 1.8–2.6 cm long, elliptic-falcate, sometimes lanceolate-falcate, apex acute, margin entire to slightly thickened, dark brown, veins absent or with some slightly conspicuous veins, strigulose, rarely glabrous, trichomes brownish. Seeds 1–4 per fruit, 3.5–4.6 × 1.9–2.4 cm, oblong, ovate to irregular, dark-brown.

Phenology:— Flowering and fruiting throughout the year, with a flowering peak from September to December and a fruiting peak from October to December.

Distribution:— Occurring throughout the Guyana Shield: Brazil (Amapá), French Guiana (Cayenne, Saint-Laurent-du-Maroni), Guyana (Barima-Waini, Cuyuni-Mazaruni, Demerara-Mahaica, East Berbice-Corentyne, Pomeroon-Supenaam, Potaro-Siparuni, Upper Demerara-Berbice), Surinam (Brokopondo, Coronie, Kabalebo, Nickerie, Para, Paramaribo, Patamaca, Sipaliwini), and Venezuela (Bolívar). Cultivated in Trinidad and Tobago, Indonesia, and Panama.

Habitat:— Non-flooded, inundated and periodically inundated forests, and savannas. It can occur from sea level up to elevations of 500 m, and sometimes even up to 800 meters. It grows mainly on white, brown, and mixed sand soils, although it can also be found on bauxite, laterite, and clayey soils. Along with E. grandiflora, E. falcata comprise the Eperua dominant forest known as wallaba forest in Guyana and Surinam.

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 this species is 501,331.224 km 2, and the estimated area of occupancy is 664.000 km 2.

Occurrence in protected areas:— Parque Nacional Montanhas do Tumucumaque (Brazil, Amapá), Réserve Naturelle des Nouragues (French Guiana, Régina), Iwokrama Rainforest Reserve (Guyana, Potaro-Siparuni), Kaieteur National Park (Guyana, Potaro-Siparuni), Mabura Hill Forest Reserve (Guyana, Upper Demerara-Berbice), Brownsberg Nature Reserve (Surinam, Brokopondo), and Central Surinam Nature Reserve (Surinam, Kabalebo).

Etymology:— The specific epithet is derived from its elliptic-falcate fruits (Bentham 1870).

Vernacular names:— apa (Irwin H.S. et al. 48277, Irwin H.S. et al. 48408, Irwin H.S. & Pires J.M. 48613, Maguire B. et al. 48408), apa-roxo (Pires J.M. & Westra L.Y.T. 48876), bioudou or bi-oudou (BAFOG 51, 7062, 7064, 7254, 7298, Mori S.A. et al. 23384, Petrov I. s.n. P03465196, Vieillescazes A. 616), biouolou-wata (BAFOG 143), birihoedoe (Stahel G. 22), bi-udu or biudu (Hoffman B. 6522, Puig H. 10263, 10285), caraota (Blanco C.A. 603, Meijeraan J.W. 42), falcaha (Angel G. 19), itoeli-walaba (Stahel G. 66), kergwalaba (Jimenez-Saa J.H. 14330), mahomillo-negro (Steyermark J.A. 86692), ouapa (Oldeman 1212), rosa-de-montaña (Foldats E. 2645), soft-wallaba (Berlo M. van collections, Redden K.M. et al. 1050, 1058, 1059), tapaka (Grenand P. 610, Puig H. 10263, 10285), walaba (Berlo M. van collections, Bhikhi C.R. et al. 79, Borsboom N.W.J. 12025, 12044, B.W. 1171, Florsch¸tz J. & Florsch¸tz P.A. 217, Jimenez-Saa J.H. 14275, 43360 (1627), Lindeman J.C. & Roon A.C. 1980/860, Lobato M. 9, Maguire B. 24778, Ogtrop F. van 1, Reuder & Roberts 12329, Sabajo P.H. & Roberts L. 11192, Vreden C.C.J. 13673), walaba-kharemeroe (Stahel G. 22), walaba-koeleroe (Stahel G. 23), walaba-of-bijlhout (Versteeg G.M. 393), wallaba (Andel T. R. van et al. collections, BAFOG 6033, Evans R. et al. 2154, Evans R. & Lewis G. 1871, Kelloff C.L. et al. 1300, Kelloff C.L. & Roesel C.C. 1155, Junker L. 507, Little E.L. Jr. 16825, McDowell T. & Gopaul D. 2451, Persaud A.C. 243, Pipoly J.J. & Boyan R. 8701, Redden K.M. et al. 4572, Stoffers A.L. et al. 62), wapa (Angel G. 19, 158, 176, BAFOG 6033, Dutrève B. 437, Garnier F.A. 138, Hallé F. 4143, Hoff M. 5895, Kodjoed J.-F. 140, Larpin D. 187, Loubry D. 1811, Mori S.A. et al. 23384, Paget D. 49, Petrov I. 124, Prévost M.F. 4221, 4232, Puig H. 10285, Sauvain M. 743, Thiel J. collections, Vieillescazes A. 616), wapa blone (Thiel J. collections), wapa-de-crique (BAFOG 143), wapa-graj ( Bena P. 1274), wapa-gras (BAFOG 1274), wapa-huileux (BAFOG 1274), wapa-rouge (Thiel J. collections), warapa (Andel T. R. van et al. 665), watapa (Andel T. R. van et al. 1007), water-wallaba (Redden K.M. et al. 3265), white-sand-wallaba (Hoffman B. 4599), zwarte-walaba (Stahel G. 22, 22a).

Uses:— Eperua falcata is highly valued for its wood, which is extensively used in Guyana and Surinam for general construction, bridge construction, light and telephone poles, shutter windows, and roof shingles. The following herbarium specimens provided information of the utilization of its wood: Andel T. R. van et al. 665, 1007, 3073, Berlo M. collections, Bhikhi C.R. et al. 79, Redden K.M. et al. 1050, 1058, 1059.

Taxonomic notes:— Eperua falcata is the only species with long and pendulous inflorescences with pendulous lateral racemes (Table 4). Morphologically, it shares the following similarities with E. leucantha and E. venosa: joined stipules, leaflets with secondary venation with one intramarginal vein very close to the margin, long and pendulous inflorescences, non-tubular corolla, exserted stamens joined in a diadelphous sheath, and sericeous ovary. Eperua falcata also shares multijugate leaves with E. leucantha and non-white flowers with E. venosa . However, notable differences set E. falcata apart from these two species. Eperua falcata has smaller adaxial petals (1.0–2.0 × 1.2– 2.5 cm) compared to E. leucantha (1.9–3.3 × 2.9–6.3 cm) and E. venosa (2.5–3.4 × 4.7–6.0 cm). Additionally, E. falcata has minutely pellucid-punctate leaflets with not all areoles having a dot, whereas E. leucantha and E. venosa have pellucid-punctate leaflets with each areola having at least one dot. Further distinctions include the lower and middle pairs of leaflets in E. falcata tending to have less asymmetrical and more rounded to obtuse bases (vs. more asymmetrical, obtuse to cuneate, rarely rounded in E. leucantha), longer [(1.1–)2.5–8.8(–11.0) cm long] and pendulous lateral racemes (vs. shorter [0.5–2.5(–3.1) cm long] and patent to erect in E. leucantha), brownish buds (vs. grayish white in E. leucantha), pink to purple petals (vs. white in E. leucantha), villous sheath (vs. sericeous in E. leucantha). From E. venosa, E. falcata also differs by multijugate leaves (vs. always 1–2(–3)-jugate in E. venosa), brownish buds (vs. grayish-white in E. venosa), glabrous adaxial petal (vs. sericeous at the base in E. venosa), and villous staminal sheath (vs. sericeous in E. venosa).

Eperua falcata and E. leucantha are allopatric species (Figure 11). Eperua falcata occurs in the Guyana Shield, with its westernmost occurrence in the Venezuelan state of Bolívar. It is a widespread and extensively collected species, although no flowering collections have been reported beyond the Bolívar state. In contrast, in Venezuela, E. leucantha occurs exclusively in the southeastern part of the Amazonas state. Eperua falcata is parapatric with E. venosa, which is restricted to the region of Gran Sabana in Venezuela, while E. falcata borders this region (Figure 11).

Selected specimens:— BRAZIL. Amapá, Laranjal do Jari, Parque Nacional do Tumucumaque, 0°16’35”N 53°6’24”W, 14 January 2005, Pereira L.A. & Cardoso J.O. 825 (RB). Oiapoque, nas margens da rodovia BR156 entre Oiapoque e Calçoene, a 21 km de Oiapoque, 3°40’33.2”N 51°46’14.1”W, 04 December 2021, Fortes E.A. & Silva G.S. da 165 (IAN, RB). CAMEROON (cultivated). Victoria Botanical Garden, 12 February 1927, Fairchild D.G. s.n. (US1716064, BR0000017324229). FRENCH GUIANA. Cayenne, Camopi, Trois sauts (haut Oyapock), saut Mansa, 31 December 1974, Grenand P. 610 (CAY, US). Cayenne, Quesnel-Chantier F.R.G., 11 December 1979, J. Thiel 619 (CAY); Exploitation forestière F.R.G., 02 February 1981, Thiel J. 792 (CAY). Kourou, montagne des Singes, 23 November 1981, Cremers G.A. 7659 (CAY, P, US). Montsinéry-Tonnegrande, crique Serpent, rive gauche à 1 m au dessus de la crique, February 1954, BAFOG 143 (U). Régina, station des Nouragues (cam inselberg), trail CE-CO, 40– 20 m elev., 4°5’30”N 52°41’0”W, 23 September 2007, Geiselman C.K. 94 (NY). Roura, placer Boulanger, bassin de la Comté, 12 November 1979, Thiel J. 582 (CAY). Saint-Élie, Saut Takari-Tanté, bassin du Sinnamary, 34 m elev., 4°37’0”N 52°56’0”W, 17 November 1989, Hoff M. 5895 (CAY); Saut Dalles, bassin du Sinnamary, 0 m elev., 4°33’0’’N 52°54’0’’W, 01 November 1991, Loubry D. 1287 (CAY). Saint-Georges, Saut Maripa, bassin de l’Oyapock, August 1973, Garnier F.A.138 (CAY). Saint-Laurent-du-Maroni, Mana, Chantier Laussat—S.F.M., bassin de La Mana, 28 November 1979, Thiel J. 593 (CAY). Maripasoula, rivière Grand Inini, bassin de l’Inini, 3°40’0”N 53°50’0”W, 07 July 1990, Sabatier D. & Prévost M.F. 3070 (CAY). Saint-Laurent-du-Maroni, bassin du Bas-Maroni, 14 April 1961, Aubréville A. 1961/236 (P, U, US). Sa ̧l, Monts La Fumée, 200–400 m elev., 3°37’0”N 53°12’0”W, 12 October 1982, Boom B.M. & Mori S.A. 1985 (CAY). GUYANA. Barima-Waini, Kariakau, Kariako Village, Barama River, 145 m elev., 7°22’0”N 59°42’0”W, 22 December 1995, Andel T. R. van et al. 665 (U, WAG); Morebo, Barima River, N.W. district, December 1908, Anderson C.W. 122 (RB). Cuyuni-Mazaruni, Bartica, Essequibo River, Moraballi Creek, near Bartica, 23 September 1929, Sandwith N.Y. 329 (RB, U, US). Imbaimadai vicinity, Mazaruni River, 0.55 miles South West of Partang River base camp, 485 m elev., 5°41’17”N 60°17’10.2”W, 23 November 2002, Redden K.M. et al. 1238 (U, US); Pakaraima Mts., Mazaruni River, NW of Chi-Chi Falls, along stream between two tepuis, approx. 1.5km above base camp 2, 762 m elev., 5°35’48.6”N 60°12’49”W, 12 February 2004, Redden K.M. et al. 1643 (U, US); Mazaruni River, unnamed falls (possible Carin Crow Falls), 0.67 miles W of base camp, 61 m elev., 5°57’4.3”N 59°19’5.2”W, 09 October 2004, Redden K.M. et al. 3265 (US); Kako River, 536 m elev., 5°31’29”N 60°50’19”W, 12 May 2009, Redden K.M. et al. 6552 (NY, US). Demerara-Mahaica, Soesdyke-Linden Hwy, 0–3 km N Kuru-Kuru Cr, 16–19 km S Georgetown-Timehri Hwy, 10–20 m elev., 6°22’0”N 58°15’0”W, 10 November 1991, Gillespie L.J. 4250 ( INPA, MO, US). East Berbice-Corentyne, White Hill on Corentyne River, 10–50 m elev., 5°6’0”N 57°19’0”W, 24 April 1990, McDowell T. & Gopaul D. 2451 (U, US). Pomeroon-Supenaam, along road between Wyaka and Mainstay, 7°15’0”N 58°31’59.9”W, 23 April 1989, Gillespie L.J. & Persaud H. 1169 (US). Potaro-Siparuni, Iwokrama Rainforest Reserve, N side of Burro-Burro R., 60–90 m elev., 4°33’0”N 58°50’0”W, 27 September 1995, Clarke H.D. 255 (CAY, U, US); Pakaraima Mts, Mt. Wokomung, Suruwabaru Creek, 1–2 km from juncture with Yuarba River, 675–750 m elev., 5°2’0”N 59°54’0”W, 07 November 1993, Henkel T.W. et al. 4142 (CAY, U, US); Kaieteur National Park, above falls, 474 m elev., 5°10’28.0”N 59°28’54.1”W, 29 August 2006, Redden K.M. et al. 3860 (CAY, US). Upper Demerara-Berbice, Berbice, Dubulay ranch, 10 m elev., 5°35’0”N 57°53’0”W, 19 October 1997, Jansen-Jacobs M.J. 5623 (U, US). Mabura Hill Forest Reserve, 13 km S of Mabura Hill, 60 m elev., 5°10’0’’N 58°42’0’’W, 13 April 1996, Clarke H.D. 1633 (CAY, U, US). Upper Takatu-Upper Essequibo, Cut Line AB from Lethem-Kurupukari road on 270°, 75 m elev., 4°34’58”N 58°44’45”W, 21 April 1992, Pennington R.T. et al. 372 (CAY, U, US). INDONESIA (cultivated). Java, Borgor City, cultivated in the Botanic Gardens Buitenzorg-Java, 30 May 1941, Wit I.i. H.C. de 70a (L). PANAMA (cultivated). Panamá, Ciudad de Panamá, Parque Natural Summit, 80 m elev., 15 February 2008, Ibáñez A. et al. 5358 (MA). SURINAM. Brokopondo, Brownsberg, Boschreserve (Forest Reserve), sectie O, 10 September 1917, B.W. 3210 (IAN, U). Coronie, Vosberg, January 1947, Burger D. 8 (U, WAG). Kabalebo, Central Surinam Nature Reserve, lower Rechter Cooppename River, 50–75 m elev., 4°21’41.2”N 56°31’8.2”W, 23 February 2004, Clarke H.D. & Rhodes J. 11085 (U). Nickerie, unknown city, Corantijne, 11 December 1949, Landsbosbeheer 902 (U). Para, Carolina, Blakawatra, 5°22’59”N 54°55’0”W, 28 November 1921, B.W. 5524 (U). Oost, Powakka, Property of Makosi family, 5°26’38.4”N 55°4’37”W, 21 May 2012, Berlo M. van et al. 63 (L). Zuid, Zanderij, September 1942, Stahel G. 22 (IAN, RB, U, WAG); banks of Sabakoe Creek, ca. 100 m W from Zanderrij to Kraka road, 4.9 km from intersection with Zanderij Hwy, 25 m elev., 5°25’0”N 55°11’30”W, 10 July 1994, Evans R. & Lewis G. 1871 (CAY, IAN, INPA, MO, P, RB, U, US). Jodensavanne-Mapane kreek area (Surinam R.), Bij kamp aan Mapane-kreek, 19 September 1953, Lindeman J.C. 4649 (F, U). Paramaribo, Forest surrounding of Carolina, 50 km, South-East of Paramaribo, 11 August 1874, Outer R.W. den 963 (L, U). Patamaca, B.S.H. ekspl. Patamaca, 02 November 1967, Borsboom N.W.J. 12025 (WAG). Sipaliwini, Boven Saramaca, Tafelberg (Table Mountain), 15 September 1944, Maguire B. 24778 (F, U, US). Boven Suriname, Berlijn, January 1844, Focke H.C. 945 (U). Coeroeni, vinicity of camp on W bank of Zuid River, across river from central Surinam Nature Preserve, ca. 10 km straight-line distance SSE of Kayserberg airstrip, 240 m elev., 3°0’3”N 56°27’3”W, 14 June 2003, Rosário C.S. & Rosário D.O. 2011 (MG, MO). Kabalebo, Tafelberg (Table Mountain), summit, trail from Augustus Creek to Lisa Creek, ca. 0.5 km from Lisa Creek, ca. 200 m from western rim of tepuí, 575 m elev., 3°55’0”N 56°12’30”W, 25 June 2001, Evans R. 3209 (MO, US). Nickerie, Fallawatra, 03 November 1971, Jimenez-Saa J.H. 14275 (U). Tapanahony, vicinity of Ulemari River, 13 km upstream from its confluence with Litani River, 150 m elev., 3°13’17”N 54°15’31”W, 04 April 1998, Evans R. & Peckham H. 2814 (L, U). TRINIDAD AND TABAGO (cultivated). Botanical Gardens, 19 August 1927, Broadway W.E. s.n. US1343487 (US). VENEZUELA. Bolívar, El Dorado, ± 65 km S. of El Dorado, 200 m elev., 25 August 1966, Meijeraan J.W. 42 (WAG). 90 km from El Dorado towards Sta. Elena, 28 December 1956, Foldats E. 2645 (US) .