Microlobius C. Presl, Abh. Koenigl . Boehm . Ges. Wiss. ser. 5, 3: 496. 1845.

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

Microlobius C. Presl, Abh. Koenigl. Boehm. Ges. Wiss. ser. 5, 3: 496. 1845.

Figs 172 , 173 , 175

Goldmania Rose ex Micheli, Mém. Soc. Phys. Genève 34: 274. 1903. Type: Goldmania platycarpa Rose [= Microlobius foetidus (Jacq.) M. Sousa & G. Andrade]

Type.

Microlobius mimosoides C. Presl [= Microlobius foetidus (Jacq.) M. Sousa & G. Andrade]

Description.

Trees or shrubs, indumentum composed of simple and granular trichomes, brachyblasts present; branches and leaves unarmed, with a strong garlic odour. Stipules caducous. Leaves bipinnate, extrafloral nectaries between pinnae pairs, and sometimes also between leaflets, but never on the petiole; pinnae 1-2 (3) pairs, opposite; leaflets 1-2 pairs, opposite, obovate or elliptic, with or without a tuft of trichomes at the base of the abaxial surface. Inflorescence units cylindrical spikes, arranged in fascicles of 2-5 spikes in pseudoracemes. Flowers 5-merous, white to yellow; calyx gamosepalous, campanulate; corolla gamopetalous, narrowly campanulate; stamens 10, anthers with an apical gland; pollen in 8-grained polyads; ovary included in the corolla. Fruit a follicle, subfalcate; valves coriaceous. Seeds obovate, wingless, white, pleurogram present.

Chromosome number.

2 n = 26 ( Goldblatt 1981a).

Included species and geographic distribution.

Monospecific ( M. foetidus ), with two varieties. Microlobius foetidus var. foetidus occurs in Mexico, Honduras and Venezuela, and M. foetidus var. paraguensis (Benth.) M. Sousa & G. Andrade is restricted to Bolivia, Paraguay, Brazil and Argentina (Fig. 175 ).

Ecology.

Seasonally dry tropical forests and woodlands.

Etymology.

From Greek, micro (= small) and lobos (= pods), in reference to the small lignified ovaries present in the original material, which were thought to be mature fruits ( Sousa and Andrade 1992).

Human uses.

Unknown.

Notes.

The status of Microlobius as a distinct genus has been questioned since its description (as Goldmania ), particularly in comparison to the original, more ample circumscription of Piptadenia ( Sousa and Andrade 1992; Mimosa clade, page 332). Phylogenetic evidence reinforced such doubts, indicating that Microlobius could be synonymised under Stryphnodendron ( Simon et al. 2016; Lima et al. 2022). Notwithstanding, morphological and ecological evidence, as well as diagnosability, supported the dismembering of Stryphnodendron into distinct genera and the maintenance of Microlobius as a monospecific genus ( Lima et al. 2022).

Among members of the Stryphnodendron clade, Microlobius is diagnosed by the following combination of characters: presence of garlic odour in the wood and leaves, petioles without extrafloral nectaries, leaves with a single pair of pinnae, opposite leaflets, and fruits follicles with white seeds ( Lima et al. 2022).

Taxonomic references.

Burkart (1969); Sousa and Andrade (1992); Lima et al. (2022).

Figures

Figure 172. Flowering branches in the Stryphnodendron clade A Gwilymia coriacea (Benth.) A. G. Lima, Paula-Souza & Scalon (Simon 3482) B Microlobius foetidus (Jacq.) M. Sousa & G. Andrade C Stryphnodendron adstringens (Mart.) Coville D S. gracile Rizzini & Heringer E Marlimorimia bahiana (G. P. Lewis & M. P. Lima) L. P. Queiroz & L. M. Borges F Pityrocarpa moniliformis (Benth.) Luckow & R. W. Jobson G Parapiptadenia blanchetii (Benth.) Vaz & M. P. Lima H Naiadendron duckeanum (Occhioni) A. G. Lima, Paula-Souza & Scalon (Simon 1457). Photo credits A, H MF Simon B T Iwane C, D H Moreira E LP Queiroz F D Cardoso G PG Ribeiro.

Figure 173. Habit and fruits in the Stryphnodendron clade A Marlimorimia psilostachya (DC.) L. P. Queiroz & Marc. F. Simon showing the tree habit B Stryphnodendron platyspicum Rizzini & Heringer (Simon 2017) showing the geoxyle subshrub habit C Gwilymia coriacea (Benth.) A. G. Lima, Paula-Souza & Scalon (Simon 3730) D Microlobius foetidus (Jacq.) M. Sousa & G. Andrade E Stryphnodendron rotundifolium Mart. fruit, manually opened revealing internal septa and seeds F Marlimorimia contorta (DC.) L. P. Queiroz & P. G. Ribeiro G Naiadendron duckeanum (Occhioni) A. G. Lima, Paula-Souza & Scalon (Pereira-Silva 15692) H Parapiptadenia rigida (Benth.) Brenan showing a yellow inflorescence and dehiscing fruit I Pityrocarpa leptostachya (Benth.) L. P. Queiroz & P. G. Ribeiro. Photo credits A R Aguilar B, C, E MF Simon D H Hulsberg F G Carvalho-Sobrinho G G Pereira-Silva H RT Queiroz https: // rubens-plantasdobrasil. blogspot. com / I LM Borges.

Figure 175. Distribution of Microlobius based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.