Erythrostemon Klotzsch in Link, Klotzsch & Otto, Icon. Pl. Rar. Horti. Berol. 2: 97, t. 39. 1844.

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

Erythrostemon Klotzsch in Link, Klotzsch & Otto, Icon. Pl. Rar. Horti. Berol. 2: 97, t. 39. 1844.

Figs 35 , 36 , 38 , 47

Poincianella Britton & Rose, N. Amer. Fl. 23(5): 327. 1930. Type: Poincianella mexicana (A. Gray) Britton & Rose [≡ Caesalpinia mexicana A. Gray (≡ Erythrostemon mexicanus (Rose) Gagnon & G.P. Lewis)]

Schrammia Britton & Rose, N. Amer. Fl. 23(5): 317. 1930. Type: Schrammia caudata (A. Gray) Britton & Rose [≡ Hoffmannseggia caudata A. Gray (≡ Erythrostemon caudatus (A. Gray) Gagnon & G.P. Lewis)]

Type.

Erythrostemon gilliesii (Hook.) Klotzsch [≡ Poinciana gilliesii Hook.]

Description.

Shrubs or small to medium-sized trees, occasionally suffrutices, unarmed (except E. glandulosus (Bertero ex DC.) Gagnon & G.P. Lewis). Stipules ovate-lanceolate, ovate, or orbicular, acute to acuminate, sometimes foliaceous, cordate and auriculate at the base, caducous or less often persistent. Leaves bipinnate, usually ending in a single terminal pinna; pinnae in 1-6 (15), opposite pairs; leaflets in 2-13 (20) opposite pairs per pinna, leaflet blades eglandular or with conspicuous black sessile glands along the margin, these sometimes sunken in the sinuses of the crenulated margin. Inflorescence an axillary or terminal raceme. Flowers bisexual, zygomorphic; hypanthium persistent as a wide or narrow, shallow or deep cup, or sometimes abscising to form a free ring around the pedicel apex as the fruit matures; sepals 5, lower sepal cucullate in bud, all sepals caducous; petals 5, free, bright golden yellow to creamish yellow, salmon pink or pink-scarlet, the median petal often with red-orange markings, the corolla diverse in form; stamens 10, free, filaments pubescent, eglandular or with stipitate glands; ovary pubescent, eglandular or with sessile or stipitate glands. Fruit a chartaceous to coriaceous or slightly woody, laterally compressed legume, elastically dehiscent with twisting valves, eglandular or with stipitate glands, (1) 2-7 (8)-seeded. Seeds yellow to ochre-brown or mottled with grey and black.

Chromosome number.

2 n = 24 [ E. exostemma (Moc. & Sessé ex DC.) Gagnon & G.P. Lewis, E. gilliesii , E. hughesii (G.P. Lewis) Gagnon & G.P. Lewis, E. melanadenius (Rose) Gagnon & G.P. Lewis, E. mexicanus (Rose) Gagnon & G.P. Lewis, E. nelsonii (Britton & Rose) Gagnon & G.P. Lewis, E. yucatanensis (Greenm.) Gagnon & G.P. Lewis] ( Fedorov 1969; Cangiano and Bernardello 2005; Mata-Sucre et al. 2020).

Included species and geographic distribution.

Thirty-four taxa in 31 species: 22 species are found across the southern USA, Mexico, and Central America, one occurs in the Caribbean (Cuba and Hispaniola), and eight occur in South America (Fig. 47 ).

Ecology.

Seasonally dry tropical forests across the Neotropics; also occurring in deserts, yungas-puna transition zones, and chaco-transition forests (Argentina, Bolivia, Chile, Paraguay).

Etymology.

From Greek, erythro - (= red) and stemon (= stamen), the type species E. gilliesii has long red exserted stamens, but this is unusual in the genus as circumscribed here.

Human uses.

Erythrostemon gilliesii is widely cultivated as a garden ornamental and is hardy in Mediterranean and temperate regions ( Lewis 2005b).

Notes.

Originally described as a monospecific genus, its circumscription was recently emended to include many species previously placed in Central American and Mexican Poincianella ( Gagnon et al. 2016).

Taxonomic references.

Britton and Rose (1930); Burkart (1936); Gagnon et al. (2016); Lewis (1998, 2005b); Queiroz (2009); Ulibarri (1996).

Figures

Figure 35. Flowers of Caesalpinieae A Tara spinosa Britton & Rose, Peru, Ancash (Hughes et al. 3043) B Cenostigma pluviosum (DC.) Gagnon & G. P. Lewis var. pluviosum, Bolivia, Santa Cruz (Wood et al. 26552) C Caesalpinia bahamensis Lam., Cuba (Lewis 1853) D Hultholia mimosoides (Lam.) Gagnon & G. P. Lewis, India E Pomaria burchellii (DC.) B. B. Simpson & G. P. Lewis, Botswana Ghanzi district F Erythrostemon coccineus (G. P. Lewis & J. L. Contr.) Gagnon & G. P. Lewis, Mexico, Oaxaca (Lewis et al. 1802) G Caesalpinia pulcherrima (L.) Sw., Honduras H Erythrostemon melanadenius (Rose) Gagnon & G. P. Lewis, Mexico, Oaxaca (Hughes et al. 2091) I Pterolobium stellatum (Forssk.) Brenan, Africa J Guilandina bonduc L., India K Gelrebia trothaei (Harms) Gagnon & G. P. Lewis, Tanzania. Photo credits A E Gagnon B, F-H CE Hughes C GP Lewis D VR Vinayaraj, India Biodiversity Portal (https: // indiabiodiversity. org / group / wild _ orchids _ of _ india / observation / show / 335155), the basionym of Hultholia mimosoides E O Bourquin, Flora of Zimbabwe (https: // www. zimbabweflora. co. zw / speciesdata / image-display. php? species _ id = 127200 & image _ id = 6) I P Van Wyk J M Sanjappa K PJ Cribb.

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