Macrosamanea Britton & Rose ex Britton & Killip, Ann. New York Acad. Sci. 35: 131. 1936.

Bruneau, Anne, de Queiroz, Luciano Paganucci, Ringelberg, Jens J., Borges, Leonardo M., Bortoluzzi, Roseli Lopes da Costa, Brown, Gillian K., Cardoso, Domingos B. O. S., Clark, Ruth P., Conceicao, Adilva de Souza, Cota, Matheus Martins Teixeira, Demeulenaere, Else, de Stefano, Rodrigo Duno, Ebinger, John E., Ferm, Julia, Fonseca-Cortes, Andres, Gagnon, Edeline, Grether, Rosaura, Guerra, Ethiene, Haston, Elspeth, Herendeen, Patrick S., Hernandez, Hector M., Hopkins, Helen C. F., Huamantupa-Chuquimaco, Isau, Hughes, Colin E., Ickert-Bond, Stefanie M., Iganci, Joao, Koenen, Erik J. M., Lewis, Gwilym P., de Lima, Haroldo Cavalcante, de Lima, Alexandre Gibau, Luckow, Melissa, Marazzi, Brigitte, Maslin, Bruce R., Morales, Matias, Morim, Marli Pires, Murphy, Daniel J., O'Donnell, Shawn A., Oliveira, Filipe Gomes, Oliveira, Ana Carla da Silva, Rando, Juliana Gastaldello, Ribeiro, Petala Gomes, Ribeiro, Carolina Lima, Santos, Felipe da Silva, Seigler, David S., da Silva, Guilherme Sousa, Simon, Marcelo F., Soares, Marcos Vinicius Batista & Terra, Vanessa, 2024, Advances in Legume Systematics 14. Classification of Caesalpinioideae. Part 2: Higher-level classification, PhytoKeys 240, pp. 1-552 : 1

Macrosamanea Britton & Rose ex Britton & Killip, Ann. New York Acad. Sci. 35: 131. 1936.

Figs 265 , 266 , 273

Pithecellobium ser. Coriacea Benth., Trans. Linn. Soc. 30: 589. 1875. Type: Pithecellobium adiantifolium (Kunth) Benth., nom. illeg. [≡ Macrosamanea discolor (Willd.) Britton & Killip]

Type.

Macrosamanea discolor (Humb. & Bonpl. ex Willd.) Britton & Rose ex Britton & Killip. [≡ Inga discolor Humb. & Bonpl. ex Willd.]

Description.

Unarmed shrubs (sometimes semi-scandent), trees or lianas. Stipules caducous. Leaves bipinnate, extrafloral nectaries absent or present in basal or median region of petiole, sometimes between pairs of pinnae, sessile, elliptic, patelliform, scutiform, round; pinnae 1-17 pairs; leaflets 2-31 pairs, opposite, variable in size and shape. Inflorescence units capitate or spicate, congested, lax, or umbelliform, axillary or terminal, rarely cauliflorous (Fig. 265H ); bracts with patelliform nectaries (Fig. 265I ) or nectaries absent. Flowers homomorphic, pedicellate or sessile; 4-5-merous; sepals 4-5, gamosepalous, the calyx green, to pinkish or brown, cylindrical to campanulate; petals 4-5, gamopetalous, the corolla white, greenish-white, rarely pinkish or brown, infundibuliform; stamens 45-248, filaments fused into a tube, stemonozone present or absent, anthers rimose; pollen in 16, 20, 24, 32 (35)-celled polyads; gynoecium 1, rarely 2-7-carpellate. Fruit a follicle, dehiscing along one margin only (Fig. 266I ), or when mature dehiscing through both margins, the body plano-convex, straight or curved. Seeds elliptic, oblong or obovate, pleurogram absent.

Chromosome number.

Unknown.

Included species and geographic distribution.

Twelve species distributed in northern South America (Brazil, Colombia, Guyana, Peru, Suriname, Venezuela), mostly in Amazonia (Fig. 273 ).

Ecology.

Riparian habitats, and in forests and open areas subject to seasonal flooding in the Amazon basin (savanna or “campinarana”).

Etymology.

From Greek, macro (= great), and Samanea (from the aboriginal samán = rain tree).

Human uses.

Unknown.

Notes.

Macrosamanea was described by Britton and Killip (1936) based on Pithecellobium sect. Samanea ser. Coriacea Benth. and later included in the Inga alliance by Barneby and Grimes (1996). Molecular analyses have supported the monophyly of Macrosamanea (Iganci 2016; Silva 2017; Koenen et al. 2020a; Ringelberg et al. 2022) and morphologically the genus is unique among the genera of Neotropical ingoid legumes in having extrafloral nectaries on the floral bracts (Lewis and Rico Arce 2005) [all except M. kegelii (Meisn.) Kleinhoonte and M. macrocalyx (Ducke) Barneby & J.W.Grimes ( Silva 2017)].

Taxonomic references.

Barneby and Grimes (1996); Britton and Killip (1936); Lewis and Rico Arce (2005); Silva (2017, 2020).

Figures

Figure 265. Foliage, inflorescence and fruits in Inga clade A, B Blanchetiodendron blanchetii (Benth.) Barneby & J. W. Grimes A flowering branch showing the capitate inflorescences clustered in efoliate pseudoracemes B detail of the heteromorphic capitate inflorescence C Leucochloron limae Barneby & J. W. Grimes leafless branch showing homomorphic capitate inflorescences and follicle fruits D Abarema diamantina E. Guerra, Iganci & M. P. Morim with axillary homomorphic capitate inflorescences E, F Robrichia schomburgkii (Benth.) A. R. M. Luz & E. R. Souza E young branch with the characteristic rusty pubescent indumentum F detail of a homomorphic capitate inflorescences G Osodendron altissimum (Hook. f.) E. J. M. Koenen detail of a homomorphic capitate inflorescence H, I Macrosamanea amplissima (Ducke) Barneby & J. W. Grimes H flowering branch with a homomorphic capitate inflorescence I bracts with showy extrafloral nectaries and visiting ants. Photo credit: A, B, D D Cardoso C GP Lewis E G Perez Huertas F F Oviedo-Brenes G E Bidaut H, I J Iganci.

Figure 266. Fruit diversity in Inga clade A young pod of Blanchetiodendron blanchetii (Benth.) Barneby & J. W. Grimes B, C Leucochloron incuriale (Vell.) Barneby & J. W. Grimes B dehisced follicular fruits exposing the seeds (C) D lomentiform fruit of Osodendron altissimum (Hook. f.) E. J. M. Koenen E indehiscent and internally septate pod of Osodendron leptophyllum (Harms) E. J. M. Koenen F auriculiform indehiscent pod of Robrichia schomburgkii (Benth.) A. R. M. Luz & E. R. Souza G young fruit of Abarema cochliacarpos (Gomes) Barneby & J. W. Grimes H dehisced twisted pod of Abarema diamantina E. Guerra, Iganci & M. P. Morim exposing the reddish endocarp and bicoloured seeds I dehisced follicle of Macrosamanea amplissima (Ducke) Barneby & J. W. Grimes J Young fruits of Zygia brenesii (Standl.) L. Rico K dehisced pods of Zygia cognata (Schltdl.) Britton & Rose L-O Indehiscent pods of Inga, with fleshy and sweety sarcotesta around the seeds L Inga grazielae (Vinha) T. D. Penn. M Inga capitata Desv. N Inga ingoides (Rich.) Willd. O Inga edulis Mart. Photo credits A, H LP Queiroz B NA Escobar C J Vieira D D Harris E P Latham, www. africanplants. senckenberg. de F LCampbell G, M, N RT Queiroz http: // rubens-plantasdobrasil. blogspot. com / I J Iganci J F Chinchila Romero K S de Jesus Calva L, O D Cardoso.

Figure 273. Distribution of Macrosamanea based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.