Dimorphandra Schott, Syst. Veg. [Sprengel] 4(2): 404. 1827.

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

Dimorphandra Schott, Syst. Veg. [Sprengel] 4(2): 404. 1827.

Figs 88 , 89 , 90

Type.

Dimorphandra exaltata Schott

Description.

Unarmed small or medium trees 3-5 (7) m, to canopy trees 40 (50) m; trunk buttressed or not; brachyblasts absent; usually pubescent in all parts with reddish to dark or light brown hairs. Stipules present or absent, caducous. Leaves bipinnate, rachis 5-90 cm long; pinnae 1-40 or more pairs; leaflets 1-50 pairs, opposite or alternate, commonly glabrous above and pubescent below, venation brochidodromous. Inflorescences short or elongated spiciform racemes, often arranged in paniculate or corymbose synflorescences; bracteoles caducous or absent. Flowers small, pale yellow to cream or dark orange to reddish, fragrant, 5-merous, diplostemonous; calyx cupuliform, tubular or campanulate; petals obovate, oblong or spatulate, glabrous or pilose; fertile stamens 5, filaments thin, with oblong, dorsifixed anthers, anther glands absent; staminodes 5, spatulate, free or connate forming a dome, with or without a rudimentary anther at the apex, usually deciduous at anthesis; pollen tricolpate monads; ovary sessile, subsessile, or stipitate, multi-ovulate, glabrous or densely hairy, style short to absent, stigma conical, terminal. Fruit dehiscent or indehiscent legumes, linear-oblong, curved or suborbicular, flat, valves leathery or woody. Seeds orbicular, flat, cylindrical or oblong.

Chromosome number.

2 n = 28 ( Muniz et al. 2020).

Included species and geographic distribution.

26 species, including four subspecies ( Silva 1986; Silva 2019), restricted to the Neotropics, occurring mostly in Brazil (23 species) and also in Bolivia, Colombia, Guyana, Peru and Venezuela (Fig. 90 ).

Ecology.

Predominates in tropical rainforests, including both terra firme and seasonally flooded ( igapó) forests, white-sand forests (campinarana), savannas, and less often in seasonally dry forests. Fruits of D. mollis Benth. are important food resources for tapirs ( Bizerril et al. 2005).

Etymology.

Dimorphandra refers to the androecium that has five stamens alternating with five staminodes, that is, two morphological forms of the stamens.

Human uses.

Dimorphandra species have the ability to fix nitrogen ( Fonseca et al. 2012) and are therefore important for improving soil fertility. Fruits are used in traditional medicine ( Féres et al. 2006). Extracts from D. gardneriana Tul. and D. mollis fruits containing the bioflavonoids rutin and quercetin are used by cosmetic and pharmaceutical industries, sometimes causing decline in natural populations ( Filizola 2013).

Notes.

The genus is classified into three subgenera: Dimorphandra (11 species), Phaneropsia Tul. (5 species) and Pocillum Tul. (10 species), which can be differentiated by leaf morphology, inflorescence architecture and fruit shape ( Silva 1986; Silva 2019). Dimorphandra seeds are dispersed by authocory, hydrochory or zoochory ( Silva 1986). Dimorphandra is not recovered as monophyletic in recent phylogenomic analyses (Fig. 87 ) in which representatives of subgenera Phaneropsia and Pocillum ( D. davisii Sprague & Sandwith and D. macrostachya Benth., respectively) form a clade independent from subgenus Dimorphandra Dimorphandra ( D. gardneriana ). Other studies with increased taxonomic sampling found similar results, but relationships were uncertain because of phylogenetic conflict ( Rocha et al. 2024). Future studies with an expanded taxonomic sample and robust topology are required for a new circumscription of the genus.

Taxonomic references.

Bentham (1840); Ducke (1925); Ragonese (1973); Silva (2019); Silva and Hopkins (2018); Silva (1981, 1986); Taubert (1894).

Figures

Figure 87. Generic relationships in tribe Dimorphandreae. For description of phylogeny and support values, see Fig. 6 caption (page 63).

Figure 88. Leaves and inflorescences of tribe Dimorphandreae A Mora paraensis (Ducke) Ducke (Simon 1663) B Stachyothyrsus staudtii Harms C Burkea africana Hook. D Dimorphandra mediocris Ducke (Simon 4209) E Dimorphandra cuprea Sprague & Sandwith (Farronay 1804) F Dimorphandra parviflora Spruce ex Benth. (Simon 1176) G Dimorphandra mollis Benth. H Dimorphandra pennigera Tul. I Dimorphandra ignea Ducke J Dimorphandra vernicosa Spreng. ex Benth. (Cardoso 3279) K Burkea africana L Dimorphandra gardneriana Tul. (Silva 21). Photo credits A, D, F, G MF Simon B Nicolas Texier (CC-BY-NC-ND- 3.0) C AR Lecuona (CC-BY-NC- 4.0) E, H, I F Javier Farronay Pacaya J D Cardoso K AE van Wyk and S Malan L G Sousa da Silva.

Figure 89. Flowers and fruits of the tribe Dimorphandreae A Dimorphandra cuprea Sprague & Sandwith (Farronay 1804) B Dimorphandra pennigera Tul. C Dimorphandra vernicosa Spreng. ex Benth. (Cardoso 3279) D Dimorphandra ignea Ducke E Stachyothyrsus staudtii Harms F Dimorphandra gardneriana Tul. (Simon 2715) G Dimorphandra macrostachya Benth. (Silva 540) H Dimorphandra cuprea Sprague & Sandwith (Farronay 1804) I Stachyothyrsus staudtii Harms J Burkea africana Hook. K-M Mora paraensis (Ducke) Ducke (K, L Costa 28). Photo credits A, B, D, H F Javier Farronay Pacaya C D Cardoso E Flora of the world F MF Simon G G Sousa da Silva I N Texier (CC-BY-NC-ND- 3.0) J C Sydes (CC-BY-NC- 4.0) K, L J Barbosa Pedrosa Costa M A Rocha Dantas.

Figure 90. Distribution of Dimorphandra based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.