1. Inga bourgonii (Aubl.) DC., Prodr. 2: 434. 1825.

Figs. 2 a-c; 3a-b

Trees, 9–15 m tall; young branches lenticellate, glabrous or glabrescent. Stipules 6–8 mm long, oblanceolate, caducous. Leaves pinnate; petiole 0.7–1.6 cm long, subcylindrical to marginate, 0–0.4 mm wide; rachis 4–9.5 cm long, marginate just below the leaflet pairs, 0.5–3 mm wide; nectaries sessile, patelliform, circular; leaflets in (2–)3 pairs; terminal leaflet pair 9–19.5 × 3.6–8.5 cm, narrowly elliptic, base asymmetric, apex shortly cuspidate; basal leaflet pair 4.8–12 × 2.2–5.5 cm, elliptic, ovate, rarely lanceolate, base asymmetric, apex shortly cuspidate; adaxial and abaxial surfaces glabrous. Inflorescences spiciform, axillary, 1–5; peduncle 1–2 cm long; rachis 2–3.5 cm long. Bracts 0.5–1 mm long, obtrullate, caducous. Flowers sessile to subsessile, 0–0.2 mm long; calyx tubular, sparsely short-sericeous, adpressed, tube 0.8–1.2 mm long, lobes 0.2–0.4 mm long, acute, irregular; corolla infundibuliform, glabrous to glabrescent, tube 3.6–4.2 mm long, lobes 0.5–1 mm long, acuminate, irregular; androecium tube 5–9 mm long, exerted, stamens 28–35, 4–7 mm long, white; nectary disc absent; gynoecium 1-carpellate; ovary 1.2–1.4 mm long, glabrous, style 9.1–15 mm long, stigma cylindrical. Fruit a nucoid legume, 12–20 × 2–3.2 cm, greenish, narrowly elliptic, glabrous, margins evident, surfaces open, transversally striate; seeds with abundant sarcotesta.

Examined material: Alta Floresta, Parque Zoobotânico Leopoldo Linhares Fernandes, 09°51’45”S, 56°04’24”W, 20.VIII.2022, fr., J. M.Fernandes 1902 (HERBAM); 15. I.2023, fr., J. M. Fernandes 1939 (HERBAM); 28.IV.2023, fl., J. M. Fernandes 1950 (HERBAM); 8. V.2023, fl., J. M. Fernandes 1953 (HERBAM). Cotriguaçu, Fazenda São Nicolau, 09°51’55”S, 58°15’59”W, 24.XI.2015, fr., J. P. Santos et al. 382 (HERBAM).ParanaÍta, 09°22’59”S, 56°44’56”W, 19.IV.2012, fl., C. R. A. Soares et al. 6050 (HERBAM).

This species has a distribution restricted to Amazonian forest and occurs from Colombia to the Guianas, as well as in Brazil, Ecuador, Peru, and Bolivia (Pennington 1997). In Brazil, it had only been recorded in the North Region, in the sates of Acre, Amazonas, Amapá, Pará, Rondônia, and Roraima (Pennington 1997; Garcia & Bonadeu 2024). The present work increases its distribution to the state of Mato Grosso, in the Central-West Region, in the municipalities of Alta Floresta, Cotriguaçu and ParanaÍta, in ombrophilous, várzia, gallery, and riparian forests (Fig. 4).

Inga bourgonii is similar to I.pezizifera Bentham (1845: 587) but differs by the shorter petiole, winged leaf rachis, smaller foliar nectaries, and sessile flowers (Pennington 1997).