Martiodendron, Gleason. Phytologia, 1935

Falcão, Marcus José De Azevedo, Torke, Benjamin M., Garcia, Gabriel Santos, Silva, Guilherme Sousa Da & Mansano, Vidal De Freitas, 2023, A Taxonomic Revision of the Neotropical Genus Martiodendron (Fabaceae: Dialioideae), Phytotaxa 578 (1), pp. 11-56 : 20

Identification key to species in Martiodendron

1. Leaflets (3–)5–6(–7), the terminal ones (3.2–)5–9(–11) cm wide; anthers pubescent; carpel laterally glabrous, pubescent only at its suture; samaras 5.5–9(–10) cm long, with the seminiferous nucleus 6–10 times wider than the narrow wings, occupying most of the fruit; riparian forests, savannas and campinaranas in Guyana and Brazil (Roraima) ............................ Martiodendron excelsum

- Leaflets (4–)6–11(–13), the terminal ones (1.1–)1.5–5.3(–8) cm wide; anthers pubescent or glabrous; carpel fully pubescent; samaras (7–)7.5–17(–20) cm long, with the seminiferous nucleus 1.5–3(–4) times wider than the expanded wings, occupying only the central part of the fruit; dense rainforests to seasonal semideciduous forests and savannas in French Guiana, Suriname, Venezuela, Bolivia, and Brazil..........................................................................................................................................................2.

2. Leaflets (4–)6–7(–8); axillary buds ovate, (2–)2.7–4.3(–5) mm long, apex almost always acute; floral buds curved along their entire length, often falcate, 1.1–1.5(–1.8) cm long; anthers pubescent and curved; Suriname, French Guiana, and Brazil (Amapá, northern Pará and northeastern Amazonas)............................................................................................. Martiodendron parviflorum

- Leaflets (6–)7–11(–13); axillary buds elliptical to oblong, (1.3–) 4–11 mm long, apex almost always acuminate to cuspidate; floral buds straight or with only the apex curved, 1.3–2.5 cm long; anthers glabrous and straight; Venezuela, Bolivia, and Brazil (Acre, Rondônia, Mato Grosso, southwest, and east of Pará, Northwestern and south Amazonas, Eastern Brazil) ...................................3.

3. Large trees, 30–45(–50) m tall; leaflets (7–)9–11(–13), the terminal ones usually narrowly oblong, (6–)7–15(–17) cm long, ca. (2.4–)3–4.6 times longer than wide; axillary buds (6–) 7.7–11 mm long; samaras (1.8–)2.7–3.8 times longer than wide; Amazonian areas of Venezuela, Bolivia, and Brazil (Acre, Amazonas, Rondônia, Mato Grosso, and southwestern and western Pará) ............... ......................................................................................................................................................................... Martiodendron elatum

- Shrubs to medium-sized trees 2–25(–32) m tall; leaflets (6–)7–9(–11), the terminal ones usually ovate to elliptical to oblong, (2.5–)5–9.5(–12) cm long, ca. (1.3–)2–3.8 times longer than wide; axillary buds (1.3–)4–7(–10) mm long; samaras 2–2.8(–3.5) times longer than wide; northeastern and eastern Brazil (extreme east of Pará, Tocantins, Piauí, Maranh ã o, Minas Gerais, Espírito Santo and Rio de Janeiro)..................................................................................................................................................................4.

4. Medium-sized trees, (8–)18–25(–32) m tall; inflorescences axillary or terminal, 4.2–10 cm long, branching directly into cymes, without elongated primary and secondary axes; stamens 5, more rarely 4+1 staminode, very rarely 4 stamens; fruits generally larger and wider, (7–)10–15 × 4–6.5 cm; coastal humid forests of eastern Brazil (Rio de Janeiro and Espírito Santo) ..................... ................................................................................................................................................................... Martiodendron fluminense

- Shrubs to medium trees 2–20(–25) m tall; inflorescences only terminal, 7–16 cm long, with elongated primary and secondary axes from which cymes form; stamens 4, more rarely 4+1 staminode, very rarely 5 stamens; fruits generally smaller and narrower, 7.5–10.5(–14) × (2.7–)3.4–5(–5.7) cm; seasonal semideciduous forests and savannas in the Cerrado, Caatinga and Amazonian ecotonal regions of northeastern and eastern Brazil (eastern of Pará, Tocantins, Piauí, Maranh ã o, and Minas Gerais) ..................... ............................................................................................................................................................ Martiodendron mediterraneum