Pseudosamanea Harms, Notizbl. Bot. Gart. Berlin-Dahlem 11(101): 54. 1930.

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

Pseudosamanea Harms, Notizbl. Bot. Gart. Berlin-Dahlem 11(101): 54. 1930.

Figs 241 , 244 , 245

Type.

Pseudosamanea guachapele (Kunth) Harms [≡ Acacia guachapele Kunth]

The phylogenetic position of Pseudosamanea is not well resolved in the Mimoseae phylogeny ( Koenen et al. 2020a; Ringelberg et al. 2022). The genus is placed in a large, putative hard polytomy in the ingoid clade (Fig. 241 ), but its exact position is difficult to ascertain, and differs across phylogenetic analyses ( Koenen et al. 2020a). Pseudosamanea is therefore not treated as part of any clade within Mimoseae and is here recognised as a single genus lineage.

Description.

Unarmed trees 6-30 m, with wide spreading crown; bark fissured and exfoliating in irregular rectangular layers. Stipules triangular to lanceolate, sericeous, caducous. Leaves bipinnate, extrafloral nectaries usually present near the petiole base, another between the terminal pair of pinnae and less frequently along the rachides; pinnae 3-13 pairs, paraphyllidia present, caducous; leaflets 5-30 pairs, obovate, elliptic or lanceolate. Inflorescence units heteromorphic umbelliform capitula, 2-6-fascicled in leaf axil, the terminal flower sessile and stouter. Flowers 5 (6-7)-merous; calyx gamosepalous, ferruginous villose; corolla gamopetalous, campanulate, lobes triangular, canescent to yellowish villose; stamens numerous, the filaments basally united into a tube; pollen in 24-32-celled polyads; ovary ovoid. Fruits indehiscent or dehiscent through one margin, oblong, laterally compressed, valves papery, puberulent, margins slightly thicker. Seeds ovoid, laterally compressed, pleurogram present (Fig. 244 ).

Chromosome number.

2 n = 26 [ P. carbonaria (Britton) E.J.M. Koenen and P. guachapele ] (Rico Arce 1992).

Included species and geographic distribution.

Three species known to date: P. carbonaria , P. cubana (Britton & P. Wilson) Barneby & J.W. Grimes and P. guachapele . Pseudosamanea species occur from the south of Mexico to the north of Peru, with one species in Cuba (Fig. 245 ; Barneby and Grimes 1996). The native range of P. carbonaria is not known with certainty, but it is presumed to be native from Colombia, Panama and Venezuela from 700-1800 m elevation and introduced in Indonesia (Koenen 2022), Central America, the Greater Antilles, Peru and Brazil ( Barneby and Grimes 1996; under Albizia carbonaria Britton). Pseudosamanea cubana is endemic to the south coast of Cuba to 50 m elevation ( Barneby and Grimes 1996). Pseudosamanea guachapele is present from the south of Mexico to the north of Peru between 0-1000 m and introduced in Brazil and Cameroon and probably elsewhere ( Barneby and Grimes 1996).

Ecology.

Pseudosamanea carbonaria grows in dry and humid forests ( Barneby and Grimes 1996), usually near water courses, its seeds are usually dispersed with the fruit by barochory and hydrochory (pers. obs.). Pseudosamanea cubana grows in riverine forests and savannas with palms ( Barneby and Grimes 1996). Pseudosamanea guachapele grows in dry forests ( Barneby and Grimes 1996). Little is known about the interactions with ants, floral visitors and pollinators.

Etymology.

From the Greek pseudo (= false) and Samanea , due to the similarity to that genus (Lewis and Rico Arce 2005).

Human uses.

The three species can be used as timber. Pseudosamanea carbonaria is cultivated for shading coffee crops, P. guachapele is used as living fencing in Colombia, and both are used as ornamentals ( Barneby and Grimes 1996).

Notes.

As defined by Barneby and Grimes (1996), Pseudosamanea included two species of macrophyllidious trees (Fig. 244F ), P. cubana and P. guachapele . The phylogenomic analyses of Ringelberg et al. (2022) showed Albizia carbonaria to be sister to Pseudosamanea , rather than grouping with species of Albizia section Arthrosamanea (Britton & Rose) Barneby & J.W. Grimes (now the genus Pseudalbizzia Britton & Rose; Peraza et al. 2022), where it had previously been classified. Albizia carbonaria was combined in Pseudosamanea based on molecular and morphological evidence ( Koenen 2022a). Although P. carbonaria is a microphyllidious tree (Fig. 244E ), it shares with the other two species of Pseudosamanea exfoliating bark (Fig. 244B, D ), heteromorphic umbelliform inflorescences (Fig. 244E, F ) in which the central flower is bigger and sessile, and oblong laterally compressed papery legumes (Fig. 244G, H ) ( Koenen 2022a). Pollen also supports this recircumscription, P. carbonaria having pollen with 32-celled polyads as in P. guachapele ( Koenen 2022a).

Taxonomic references.

Barneby and Grimes (1996); Koenen (2022a); Lewis and Rico Arce (2005).

Figures

Figure 241. Phylogenetic position of Cedrelinga and Pseudosamanea in tribe Mimoseae. For description of phylogeny and support values, see Fig. 6 caption (page 63).

Figure 244. General morphology in Pseudosamanea species A, B, E, G Pseudosamanea carbonaria (Britton) E. J. M. Koenen (left) A habit B exfoliating bark E bipinnate microphyllidious leaves and umbelliform capitula G papery oblong laterally compressed pods C, D, F, H Pseudosamanea guachapele (Kunth) Harms (right) C habit D exfoliating bark F bipinnate macrophyllidious leaves and umbelliform capitula H papery oblong laterally compressed fruits. Scale bars: 2 cm (E); 4 cm (F); 3 cm (G); 2.5 cm (H). Photo credits A Bioexploradores Farallones, iNaturalist (https: // www. inaturalist. org / photos / 30575576) B, D, H A Fonseca-Cortes C Juan Manuel de Roux, iNaturalist (https: // www. inaturalist. org / photos / 112891215) E Juan Manuel de Roux, iNaturalist (https: // www. inaturalist. org / photos / 54043095) F Cynthia Tercero, iNaturalist (https: // www. inaturalist. org / photos / 59667691) G Juan Carlos Delgado Madrid, iNaturalist (https: // www. inaturalist. org / photos / 64538395).

Figure 245. Distribution of Pseudosamanea based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.