Havardia Small, Bull. New York Bot. Gard. 2: 91. 1901.

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

Havardia Small, Bull. New York Bot. Gard. 2: 91. 1901.

Figs 217 , 220

Pithecolobium sect. Ortholobium Benth., Trans. Linn. Soc. London 30: 592. 1875. Type: Pithecellobium albicans (Kunth) Benth. [≡ Acacia albicans Kunth (≡ Havardia albicans (Kunth) Britton & Rose)]

Type.

Havardia brevifolia (Benth.) Small [≡ Pithecellobium brevifolium Benth. (= Havardia pallens (Benth.) Britton & Rose)]

Description.

Trees or bushy treelets 2-9(-12) m. Stipules spinescent. Leaves bipinnate, extrafloral nectaries sessile, shallowly cupular, thick-rimmed, inserted near or below mid-petiole, rarely 2, rarely at very base, sometimes a little above mid-petiole, sometimes rudimentary; pinnae 1-11 (13) pairs; leaflets 7-36 pairs per pinna, alternate, rarely opposite, linear, linear-oblong, to narrowly oblong-obovate, venation simple or pinnate. Inflorescence 6-37-flowered capitula or capituliform racemes. Flowers sessile or very shortly pedicellate, homomorphic, 5-merous; calyx hemispherical, shallowly campanulate to deeply campanulate, teeth deltoid; corolla campanulate, narrowly vase-shaped to subcylindrical, lobes recurving to erect; stamens (28) 30-52; pollen in 16-celled polyads, more or less isodiametric; intrastaminal disc 5-lobed or simple callosities; ovary subsessile or shortly stipitate, slenderly ellipsoid, style about as long as stamens, the stigma poriform. Fruits oblong to broad-linear, straight, plano-compressed legumes, 8-13-seeded, valves framed by a bluntly 3-angulate suture, valves chartaceous or thinly coriaceous, stiffly papery, low-convex over each seed on one face or on both, externally veinless, the cavity continuous; dehiscence tardy, inert, through both sutures. Seeds transverse, orbicular or oblong-elliptic, compressed-disciform and flattened around the periphery, funicle distally sigmoid, pleurogram U-shaped to closed.

Chromosome number.

Unknown.

Included species and geographic distribution.

Three species, almost entirely distributed in Mexico mainly in the north and the Yucatan peninsula, extending marginally north into the USA (south Texas), and south into northern Guatemala and Belize (Fig. 220 ).

Ecology.

Largely confined to seasonally dry, drought deciduous woodland and arid thorn scrub and arid mattoral in the Sonoran desert, Tamaulipan plains and coastal thickets on sand, secondary forest, and extending weakly into lowland rainforest, occasionally on limestone. In parts of Mexico, abundant. For example, H. albicans (Kunth) Britton & Rose is very common in the peninsula of Yucatán, and H. pallens is abundant in parts of northern Mexico.

Etymology.

Named after Dr. Valery Havard (1846-1927), U.S. Army, a diligent student of the North American flora.

Human uses.

The boiled wood of H. albicans is used in the chemical industry to colour cement (e.g., for swimming pools; Duno 2014) and it has been used as an addition to the fermented psychoactive drink Pulque. In addition, the stem of H. pallens is used in the construction of fences and the wood is used for the manufacture of furniture.

Notes.

Britton and Rose (1928) provided the first taxonomic revision of Havardia including three other species which are now ascribed to Sphinga . The fruits of the two genera are similar. Barneby and Grimes (1996) updated this taxonomic treatment recognising five species, but Havardia , as circumscribed by Barneby and Grimes (1996), is not supported as monophyletic in the analyses of Koenen et al. (2020a), Ringelberg et al. (2022) or Tamayo-Cen et al. (2022), prompting assignment of two species to the new segregate genus Gretheria ( Tamayo-Cen et al. 2022), based on floral characters.

Taxonomic references.

Barneby and Grimes (1996); Britton and Rose (1928); Calderón de Rzedowski (2007); Small (1991); 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 220. Distribution of Havardia based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.