Haematoxylum L., Sp. Pl. 1: 384. 1753.

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

Haematoxylum L., Sp. Pl. 1: 384. 1753.

Figs 36 , 38 , 51

Haematoxylon L., Philosophia Botanica: 34. 1764, orth. var.

Cymbosepalum Baker, Bull. Misc. Inform. Kew 1895 (100-101): 103. 1895. Type: Cymbosepalum baronii Baker [= Haematoxylum campechianum L.]

Type.

Haematoxylum campechianum L.

Description.

Multi-stemmed shrubs to medium-sized trees, armed with scattered straight conical spines, and short, lateral spinescent shoots; mature trees with conspicuously fluted trunks, shrubs often with ribbed branches. Stipules minute, acuminate, caducous. Leaves pinnate or bipinnate (both can be present on the same individual in some species), eglandular; pinnate leaves with 2-6 pairs of leaflets; bipinnate leaves with 1-3 pairs of pinnae plus a terminal pinna, each pinna with 2-5 (6) pairs of opposite leaflets. Inflorescence a terminal or axillary raceme or panicle. Flowers bisexual, actinomorphic to zygomorphic; the short hypanthium persisting in fruit as a small cup; sepals 5, free, the lower sepal cucullate and slightly covering the other 4 in bud, sepals caducous; petals 5, yellow to pale yellow or white, free; stamens 10, free, filaments pubescent, particularly on the lower half; ovary glabrous to pubescent. Fruit laterally flattened, membranous to chartaceous, dehiscing along the middle of the valves, or near the margin of the fruit, but never along the sutures, 1-3-seeded. Seeds oblong to reniform, flattened.

Chromosome number.

2 n = 24 ( H. campechianum ) ( Fedorov 1969).

Included species and geographic distribution.

Five species: two in Central America (Salvador to Costa Rica), Mexico, South America (Colombia and Venezuela) and the Caribbean (perhaps introduced), two endemic to Mexico, and one in Southern Africa (Namibia; Fig. 51 ).

Ecology.

Deserts, seasonally dry tropical semi-deciduous scrub and thorn scrub, sandy riverbeds, and dry rocky hillsides. One species ( H. campechianum ) is known to grow in frequently inundated marshy areas by rivers.

Etymology.

From Greek, haemato - (= bloody) and xylon (= wood), alluding to the blood-red heartwood of H. campechianum which produces a brilliant red dye.

Human uses.

The heartwood of H. campechianum is the source of a colourless chemical, haematoxylin, which upon oxidation turns to haematein, a commercial dark violet dye used for wool, silk, cotton, fur, leather, bone and synthetic fibre dying, and with iron chromium mordants to obtain red and black; also used as a stain in microscopical preparations (particularly to show up cell nuclei), and ink for writing and painting and the rich red colour has been used to adulterate wine. Species are also used medicinally, as ornamentals and living hedges and the bee flowers yield a high-quality honey ( Lewis 2005b).

Notes.

This genus is easily diagnosable by the ascending secondary veins of its leaflets, which form a sharp angle with the primary vein. There is a key to species by Durán and Sousa (2014).

Taxonomic references.

Barreto Valdés (2013); Curtis and Mannheimer (2005); Durán and Ramírez (2008); Durán and Sousa (2014); Gagnon et al. (2016); Lewis (2005b); Ross (1977); Roux (2003); Standley and Steyermark (1946).

Figures

Figure 36. Fruits of Caesalpinieae A Hererolandia pearsonii (L. Bolus) Gagnon & G. P. Lewis, Namibia, Sesriem Canyon B Haematoxylum brasiletto H. Karst., Mexico (Lewis 2057) C Lophocarpinia aculeatifolia (Burkart) Burkart, Paraguay, (Fortunato 8650) D Hoffmannseggia arequipensis Ulibarri, Peru, Arequipa, (Hughes et al. 2342) E Balsamocarpon brevifolium Clos, Chile (Baxter et al. DCI 1859) F Zuccagnia punctata Cav., Argentina, Mendoza G Cordeauxia edulis Hemsl., Somalia H Erythrostemon coccineus (G. P. Lewis & J. L. Contr.) Gagnon & G. P. Lewis, Mexico, Oaxaca (Lewis et al. 1802) I Paubrasilia echinata (Lam.) Gagnon, H. C. Lima & G. P. Lewis, Brazil J Libidibia paraguariensis (Parodi) G. P. Lewis, Bolivia, Santa Cruz (Hughes 2475) K Coulteria mollis Kunth, Guatemala (Lewis et al. 1714) L Cenostigma pluviosum var. cabralianum (G. P. Lewis) Gagnon & G. P. Lewis, Brazil (Lewis et al. 2019) M Pomaria jamesii (Torr. & A. Gray) Walp., USA. Photo credits A AA Dreyer B, I, K, L GP Lewis C RH Fortunato D, H, J CE Hughes E P Baxter F Italo Specogna, Flora mendocina (http: // www. floramendocina. com. ar / clase _ 3 / zuccagnia _ punctata _ p 9558. html) G M Thulin M P Alexander, SEINet Arizona Chapter (https: // swbiodiversity. org / seinet / imagelib / imgdetails. php? imgid = 253949).

Figure 38. Vegetative traits of the Caesalpinieae A Hoffmannseggia minor (Phil.) Ulibarri, Bolivia B Hererolandia pearsonii (L. Bolus) Gagnon & G. P. Lewis, Namibia, Sesriem Canyon C Moullava spicata (Dalzell ex Wight) Nicolson, India, Maharastra D Cordeauxia edulis Hemsl., undersurface of leaflets showing glands, Somalia E Pomaria austrotexana B. B. Simpson, USA, Texas F Small tree of Erythrostemon nicaraguensis (G. P. Lewis) Gagnon & G. P. Lewis, Nicaragua, Esteli (Hawkins et al. 4) G Leopard bark of Libidibia paraguariensis (D. Parodi) G. P. Lewis, Bolivia, Santa Cruz (Hughes 2475) H Lenticelled bark of Erythrostemon nicaraguensis (G. P. Lewis) Gagnon & G. P. Lewis, Nicaragua, Esteli (Hawkins et al. 4) I Young flush of leaves of Cenostigma pluviosum var. intermedium (G. P. Lewis) Gagnon & G. P. Lewis, Brazil, Bahia (Lima et al. 7901) J Fluted trunk of Haematoxylum brasiletto H. Karst., Mexico, Oaxaca, (Hughes 1947) K Prickles on woody protuberances on a young trunk of Paubrasilia echinata (Lam.) Gagnon, H. C. Lima & G. P. Lewis, Brazil, Bahia (Lima et al. 7909) L Recurved spines of Biancaea decapetala (Roth) O. Deg., Peru, Ancash, (Hughes et al. 3055). Photo credits A GP Lewis B AA Dreyer C Shivaprakash, iNaturalist (https: // inaturalist. ca / observations / 81864757) D M Thulin E WR Carr F-H, J CE Hughes I, K, L E Gagnon.

Figure 51. Distribution of Haematoxylum based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.