Chloroleucon (Benth.) Britton & Rose, N. Amer. Fl. 23(1): 36. 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

Chloroleucon (Benth.) Britton & Rose, N. Amer. Fl. 23(1): 36. 1928 nom. cons.

Figs 253 , 255

Pithecellobium sect. Chloroleucon Benth., Lond. J. Bot. 3: 197, 221. 1844. Type: Pithecellobium vincentis Benth. [≡ Chloroleucon mangense var. vincentis (Benth.) Barneby & J.W. Grimes]

Type.

Chloroleucon vincentis (Benth.) Britton & Rose [≡ Pithecellobium vincentis Benth. (≡ Chloroleucon mangense var. vincentis (Benth.) Barneby & J.W. Grimes)]

Description.

Trees and shrubs, with dimorphic vegetative branches, the bark usually smooth and a patchwork of grey, white, and green (Fig. 253G ), usually randomly armed with solitary or paired axillary spines (modified sterile peduncles), with characteristic striate resting buds and flowering usually preceding leafing; brachyblasts often present. Stipules subulate, filiform, linear, or oblanceolate-elliptic, caducous, often lacking. Leaves bipinnate (Fig. 253I-J ), partly or wholly caducous, extrafloral nectaries present on petiole, and leaf and pinnae rachides; pinnae 1-9 pairs, opposite; leaflets (4) 7-46 pairs, opposite or subopposite, reduced to 1 pair in Ch. chacoënse (Burkart) Barneby & J.W. Grimes. Inflorescences solitary or fasciculate, pedunculate, capitate (Fig. 253I ) or densely shortly racemose-spicate, emerging from a cone of imbricate, striately veined, caducous perules. Flowers of each inflorescence either homomorphic or commonly dimorphic (Fig. 253I ) and then the terminal (central) one stouter and with a modified androecium, perianth usually 5-merous, calyx narrowly campanulate, short-toothed, corolla narrowly tubular, androecium with 10-30 stamens (up to 52 in Chloroleucon chacoënse), exserted or not from the corolla, filaments white to greenish; pollen in 16, 18, 24 or 32-celled polyads with almost smooth ornamentation; ovary sessile, stigma minutely dilated. Fruits linear or narrowly oblong, straight, falcate (Fig. 253J ), or coiled into a compressed or open helix (Fig. 253H ), or erratically twisted, the valves woody or coriaceous, dehiscence tardy and inert through one or both sutures. Seeds compressed-lenticular, testa hard, pleurogram present.

Chromosome number.

2 n = 26 [ Ch. tenuiflorum (Benth.) Barneby & J.W. Grimes; Darlington and Wylie (1956); Fedorov (1969)].

Included species and geographic distribution.

Ten species, north-west Mexico (one species) to the Antilles (two species), with the remaining species in South America as far south as Argentina and south-east Brazil (Fig. 255 ). Chloroleucon mangense (Jacq.) Barneby & J.W. Grimes was separated into six varieties by Barneby and Grimes (1996).

Ecology.

Warm temperate and tropical lowland, less often in submontane seasonally dry forest, xeromorphic brush-woodland, coastal thicket, wooded grassland, shrubland and desert.

Etymology.

From Greek, chloro - (= greenish yellow) and leuco - (= white), probably referring to the patchwork bark of most species.

Human uses.

Used for construction timber, as a medicinal tea, and the fruits as human food [ Ch. dumosum (Benth.) G.P. Lewis in Bahia, Brazil; Queiroz (2009)].

Notes.

Record (1927) was the first to publish the generic name Chloroleucon and cited Ch. guatemalense Britton & Rose ex Record [now Ch. mangense var. leucospermum (Brandegee) Britton & Rose] as the generic type. However, it was not validly published because he did not provide a generic description.

The species of Chloroleucon separate into two well supported groups based on whether the flowers in the inflorescence are homomorphic or heteromorphic (Almeida et al., in prep.). Barneby and Grimes (1996) provide a key to the ten species and to the six varieties recognised in Ch. mangense .

Taxonomic references.

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

Figures

Figure 253. Flower, fruit and vegetative characters of the Samanea clade A Samanea inopinata (Harms) Barneby & J. W. Grimes, tree, Brazil B, C Samanea saman (Jacq.) Merr. B inflorescences in bud and mature flower, El Salvador (Hughes 1241) C bipinnate leaves, Sri Lanka D Samanea inopinata, rough bark of trunk and main branches, Brazil E, F Samanea saman E flowers, cultivated in Hawaii F fruits G Chloroleucon mangense (Jacq.) Barneby & J. W. Grimes, trunk bark, Comayagua valley, Honduras H, I Chloroleucon acacioides (Ducke) Barneby & J. W. Grimes H fruits, Mato Grosso, Brazil I foliage and inflorescences, Brazil J Chloroleucon foliolosum (Benth.) G. P. Lewis, foliage and fruit, Bahia, Brazil (Lewis 1972). Photo credits A, D, F E Ner B, G CE Hughes C P Rajatewa E GD Carr H D Sasaki I D Cardoso J GP Lewis.

Figure 255. Distribution of Chloroleucon based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.