Ebenopsis Britton & Rose, N. Amer. Fl. 23: 33. 1928.

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

Ebenopsis Britton & Rose, N. Amer. Fl. 23: 33. 1928.

Figs 217 , 224

Hoopesia Buckley, Proc. Acad. Nat. Sci. Philadelphia 13: 453. 1862. Type: Hoopesia arborea Buckley [= Ebenopsis ebano (Berland.) Barneby & J.W. Grimes]

Siderocarpos Small, Bull. New York Bot. Gard. 2: 91. 1901, nom. illeg., non Siderocarpus Pierre, Not. Bot. Sapot.: 31. 1890 ( Sapotaceae ). Type: Siderocarpos flexicaulis (Benth.) Small [≡ Acacia flexicaulis Benth. (= Ebenopsis ebano (Berland.) Barneby & J.W. Grimes)]

Type.

Ebenopsis ebano (Berland.) Barneby & Grimes [≡ Mimosa ebano Berland.]

Description.

Trees and shrubs, 2-8 (20) m. Stipules early lignescent, persistent. Leaves bipinnate, extrafloral nectaries interpinnal, cupular, short-stipitate; pinnae 1-4 pairs; leaflets 2-7 pairs per pinna, opposite, oblong, oblong-obovate rhombic-oblong, obovate-elliptic to suborbicular, venation palmate. Inflorescences spikes or capitula arising from brachyblasts. Flowers sessile, homomorphic, 5-merous; calyx campanulate; corolla tubular, lobes erect; stamens 32-66, the tube included or barely exserted from the corolla; pollen in 16-celled polyads, more or less isodiametric; intrastaminal disc lobed or small callosities. Fruits massive, compressed sausage-like, erect or slightly curved legumes, the woody valves produced inwardly as pithy interseminal septa, the exocarp in age breaking into polygons; dehiscence tardy, inert, the sutures at first separating at each end of pod but not gaping, ultimately separating through their whole length. Seeds transverse on straight, subterete funicle, irregularly globose, resembling chickpeas, red-castaneous in colour.

Chromosome number.

Unknown.

Included species and geographic distribution.

Three species. Markedly disjunct across Mexico in Baja California, Sonora-Sinaloa, north-eastern Mexico, and the northern half of the Yucatán Peninsula, the genus almost endemic to Mexico, but extending into south Texas (Fig. 224 ).

Ecology.

In tropical and subtropical arid thickets and dry forests and adjacent desert hillsides and desertic fringes in Baja California and Sonora, mostly below 500 m, cultivated in Florida. Often locally abundant as a shrubby treelet forming thickets in thorn scrub and chaparral on impermeable caliche substrates in parts of Tamaulipas and Baja California. The fruits ripen and open slowly and are sometimes described as indehiscent, but after falling, often entire, the valves are eventually fully dehiscent shedding their seeds passively on the ground.

Etymology.

From the words Diospyros ebano ( Diospyros crassiflora Hiern, Ebeneaceae ) and ópsis ( “aspect”, “appearance”). The wood resembling African ebony in appearance.

Human uses.

In Mexico, the hard wood is used for fence posts and provides high quality charcoal, perhaps accounting for the scarcity of larger trees.

Notes.

Britton and Rose (1928) provided the first taxonomic revision of the genus, which was subsequently updated by Barneby and Grimes (1996). The fruit and seeds of Ebenopsis are striking and easily distinguish the genus from all other members of the Pithecellobium clade being generally straight and lignescent, septate internally, with thickened woody valves which are black and finely fissured in a polygon pattern, with plump irregularly subglobose, red-castaneous seeds.

Taxonomic references.

Barneby and Grimes (1996) with illustration; Britton and Rose (1928); Tamayo-Cen et al. (2022).

Figures

Figure 217. Morphology of selected species of the Pithecellobium clade A Ebenopsis ebano (Berland.) Barneby & J. W. Grimes, fruit B, C Havardia albicans (Kunth) Britton & Rose B leaves C inflorescence D Gretheria campylacantha (L. Rico & M. Sousa) Duno & Torke, fruit E Ricoa leptophylla (DC.) Duno & Torke, inflorescence and young flowers F Painteria elachistophylla (A. Gray ex S. Watson) Britton & Rose, fruit G Pithecellobium dulce (Roxb.) Benth. habit H Pithecellobium unguis-cati (L.) Benth. inflorescence I Pithecellobium lanceolatum (Humb. & Bonpl. ex Willd.) Benth. pod and seeds J Pithecellobium winzerlingii Britton & Rose pod and seed K Sphinga acatlensis (Benth.) Barneby & J. W. Grimes flowers L Sphinga platyloba (Bertero ex DC.) Barneby & J. W. Grimes flowers. Photo credits A, E, F, H R Duno de Stefano B, C, J GA Romero Gonzalez D, I, K CE Hughes G D Pedersen L C Ramirez.

Figure 224. Distribution of Ebenopsis based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.