Inga cinnamomea Spruce ex Benth., Trans.Linn. Soc. London

Fernandes, José Martins, Soares, Célia Regina Araújo, Koch, Ana Kelly, Duarte, Temilze Gomes & Almeida, Anderson Alex Sandro Domingos de, 2025, New records of the mimosoide clade (Caesalpinioideae, Leguminosae) for the state of Mato Grosso, Brazil, Rodriguesia (e 00312024) 76, pp. 1-11 : 6-7

2. Inga cinnamomea Spruce ex Benth., Trans.Linn. Soc. London 30(3): 606. 1875. Fig. 3 c-e

Trees, ca. 7 m tall; young branches lenticellate, glabrescent. Stipules 15–18 mm long, narrowly elliptic, caducous. Leaves pinnate, petiole 5.5–6.6 cm long, cylindrical; rachis 10.5–12 cm long, subcylindrical; nectaries sessile, patelliform, circular; leaflets in 3 pairs; terminal leaflet pair 17.4–23 × 9.5–11 cm, elliptic to ovate-elliptic, base attenuate, apex shortly caudate basal leaflet pair 13–14.7 × 5.7–7.3 cm, elliptic to ovate, base attenuate, apex shortly caudate; adaxial and abaxial surfaces with glandular trichomes. Inflorescences capituliform, globose, axillary, 2–3; peduncle 5.5–6.7 cm long; rachis 2–3 mm long. Bracts 6–7 mm long, narrowly obtrullate, caducous. Flowers pedicellate, 1–1.8 mm long; calyx infundibuliform, tube 4.5–6.5 mm long, glabrous, laterally torn, lobes 0.8–1 mm long, acute to acuminate, irregular, pubescent; corolla infundibuliform, tube 6–6.8 mm long, lobes 1–1.3 mm long, acuminate, regular, pubescent; androecium tube 6.5–8.5 mm long, included, stamens 56–60, 5.5–7 mm long, white; nectary disc absent; gynoecium 1-carpellate; ovary 1.6–2 mm long, trichomes sparse at the apex, style 14.7–15.5 mm long, stigma cylindric. Fruits not seen.

Examined material: Itaúba, resgate da flora da Usina Hidrelétrica ColÍder, lote F próximo a balsa, 19.V.2016, fl., M. E. Engels & A. S. Bezerra 4483 ( HERBAM; photography MBM 413393!).

This species occurs in Amazonia in Bolivia, Brazil, Colombia, Ecuador, French Guiana and Peru, always below 500 meters elevation ( Pennington 1997). In Brazil, it is only cited for states in the North Region (Acre, Amazonas, Amapá, Pará and Rondônia) in riparian, gallery, terra firme, and várzia forests ( Pennington 1997; Garcia & Bonadeu 2024). Here, we increase the distribution to Mato Grosso, in the municipality of Itaúba, where it is found in areas of the Planalto dos Parecis in transition vegetation between Amazonia and the Cerrado ( Fig. 4 ).

Inga cinnamomea is a well-defined species morphologically; it is not similar to any other species in Brazil. According to Pennington (1997), is similar to I. jinicuil G. Don (1832: 391) that occurs in Mexico, Central America and Ecuador, but I. cinnamomea differs by having a petiole 2.9–7 cm long, leaflets with 8–13 veins, and a calyx tube 2.75–5 mm long.

Figures

Figure 3 – a-b. Inga bourgonii – a. leaf nectary; b. flower. c-e. I. cinnamomea – c. branch with leaf and inflorescences; d. leaf nectary; e. flower. f-i. I. duckei – f-g. leaf nectaries; h. inflorescences; i. flower. j-n. I. huberi – j. leaf; k. leaf nectary; l. inflorescence; m. flower; n. fruit. (a-b. Fernandes 1950; c-e. Engels & Bezerra 4483; f-g. Fernandes 2052; h-i. Soares et al. 1329; j-m. Souza & Felito 1036; n. Zanin et al. 1182).

Figure 4 – Distribution of Inga bourgonii, I. cinnamomea, I. duckei Inga huberi, Macrosamanea pubiramea var. pubiramea and Piptadenia pteroclada in Mato Grosso.