Osodendron E.J.M. Koenen, PhytoKeys 205: 456. 2022.

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

Osodendron E.J.M. Koenen, PhytoKeys 205: 456. 2022.

Figs 265 , 266 , 268 , 272

Type.

Osodendron altissimum (Hook. f.) E.J.M. Koenen [≡ Albizia altissima Hook. f.]

Description.

Trees, rarely shrubs, 5-35 m tall (Fig. 268F ), unarmed or sometimes with spine-like projections; indumentum usually dense ferruginous pubescent. Stipules deltoid, elliptically oblong, lanceolate to linear, sometimes asymmetrical, caducous leaving scars. Leaves bipinnate; leaf glands usually present; pinnae (3) 5-30 (34) pairs, opposite, sometimes the lowermost pair sub-opposite and usually distinctly shorter than other pairs; leaflets (7) 13-40 (48) pairs. Inflorescence units sub-globose dimorphic and axillary capitula (Fig. 265G ). Flowers 4-5-merous, sessile or shortly stipitate, green, greenish-white to white; calyx gamosepalous; corolla gamopetalous; stamens with 10-25 filaments basally united into a staminal tube, white; pollen in 32-celled polyads; ovary 1-3 mm long, pubescent, puberulent or with a few scattered hairs. Fruit indehiscent, tardily breaking up into one-seeded articles or not, straight, slightly curved to coiled (Fig. 266D, E ). Seeds orbicular to nearly elliptic, with a hard testa; pleurogram U-shaped or O-shaped.

Chromosome number.

2 n = 26 ( Cave 1960).

Included species and geographic distribution.

Three species, O. altissimum , O. dinklagei (Harms) E.J.M. Koenen and O. leptophyllum (Harms) E.J.M. Koenen, in tropical West and Central Africa, from Senegal and Guinea Bissau to Zambia and Angola (Fig. 272 ).

Ecology.

Osodendron is found mainly in tropical wet forests extending to the savanna belt. Osodendron dinklagei and O. leptophyllum can also be found in swampy areas, forest edges or gallery forest ( Koenen 2022b).

Etymology.

The word " oso " refers to a recipe from African cuisine, mainly from the area of Ghana and Guinea, which uses O. altissimum seeds as a base for preparation of a local fermented food (Jolaoso 2014).

Human uses.

Osodendron is important for food in Africa, where O. altissimum seeds are used in cooking and human nutrition (Jolaoso 2014). The leaves of this species also have anti-inflammatory and analgesic properties, confirmed by phytochemistry and animal testing ( Aderibigbe et al. 2015).

Notes.

The species currently assigned to Osodendron were placed in Cathormion (Benth.) Hassk. and Albizia , but the phylogenomic study of Koenen et al. (2020a) indicated that the type species of Cathormion belonged to the Albizia clade. Subsequently, Ringelberg et al. (2022) revealed that the three species assigned to Osodendron are more closely related to the genus Robrichia than to Albizia providing support for the recognition of the new genus Osodendron ( Koenen 2022b).

Osodendron species are restricted to Africa, whereas Robrichia species have a Neotropical distribution, and they can be differentiated from Robrichia mainly by the shape of their fruits, which are straight, slightly curved, coiled and/or twisted (vs. contorted or “ear-shaped” in Robrichia ) ( Koenen 2022b). The three Osodendron species can be distinguished by the number of pinnae, presence of leaf glands and fruit shape and articulation ( Koenen 2022b).

Taxonomic references.

Jolaoso (2014); Koenen (2022b).

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 268. Habitat and habit diversity in Inga clade A Abarema cochliacarpos (Gomes) Barneby & J. W. Grimes, arborescent shrub in sandy coastal scrub B Robrichia schomburgkii (Benth.) A. R. M. Luz & E. R. Souza, buttressed emergent tree in rainforests C Leucochloron incuriale (Vell.) Barneby & J. W. Grimes, tree with thick corky bark in semi-deciduous forests D Inga bifoliolata D. B. O. S. Cardoso & Amorim, scandent treelet of rainforest understory E Zygia juruana (Harms) L. Rico treelet of the Amazonian inundated forests (igapo) F Osodendron dinklagei (Harms) E. J. M. Koenen, giant tree from the Guinean forests in West tropical Africa. Photo credits A RT Queiroz https: // rubens-plantasdobrasil. blogspot. com / B G Perez Huertas C F Ventura D, E D Cardoso F W Hawthorne.

Figure 272. Distribution of Osodendron based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.