Pseudosenegalia Seigler & Ebinger, Novon 25(2): 199. 2017.

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

Pseudosenegalia Seigler & Ebinger, Novon 25(2): 199. 2017.

Figs 192 , 194

Type.

Pseudosenegalia feddeana (Harms) Seigler & Ebinger [≡ Acacia feddeana Harms]

Description.

Unarmed trees (some to 12 m) or shrubs; bark white to grey-white and smooth; brachyblasts present at some or all nodes. Stipules small, persistent or falling late, not spinescent. Leaves bipinnate, not sensitive; pinnae 1-7 pairs; paraphyllidia absent; leaflets opposite, 11-26 pairs per pinna; gland present at apex of petiole and (when leaves multijugate) on rachis below the uppermost 1-2 pinna pairs, sessile. Inflorescences comprising pedunculate, loosely flowered spikes, 1 or 2 in leaf axils; peduncles lacking a multi-bracteate involucre. Flowers hermaphrodite, uniform, 5-merous, with a basal nectariferous disk, sessile, white or pale creamy white; perianth connate, valvate, scarious; stamens numerous (100-150), free; anther glands absent; pollen not studied; ovary stipitate. Fruits dehiscent along both sutures, flattened or elliptic in cross-section, valves coriaceous, twisting after dehiscence. Seeds not winged, exarillate; pleurogram U-shaped (open at hilar end) or absent in P. feddeana (Fig. 192H, K ).

Chromosome number.

Unknown.

Included species and geographic distribution.

Two species, endemic to Bolivia (Fig. 194 ).

Ecology.

In seasonally dry tropical forest, dry scrub and thorn-scrub between 1300 and 3300 m elevation.

Etymology.

The generic name Pseudosenegalia is from Greek pseudo (= false) + Senegalia , in reference to a superficial resemblance to that genus.

Human uses.

Pseudosenegalia feddeana is important locally as a forage plant and its wood is used as a fuel; also, its seeds are edible and used as a coffee substitute ( Rico-Arce 2007, as Acacia ).

Notes.

Seigler et al. (2017) described Pseudosenegalia as a segregate of Senegalia for two New World species which lack prickles, namely, P. feddeana and P. riograndensis (Atahuachi & L. Rico) Seigler & Ebinger. In that work the two species were comprehensively described and illustrated, and an identification key provided. A phylogenetic study based on plastid and nuclear sequence data supported the monophyly of Pseudosenegalia which was resolved as sister to a clade containing Parasenegalia and Mariosousa ( Seigler et al. 2017). A revised key that included all species of both genera is given in Seigler and Ebinger (2018).

Both species of Pseudosenegalia were originally described under Acacia and subsequently transferred to Senegalia by Seigler et al. (2006a) and Seigler and Ebinger (2009). Prior to the recognition of Pseudosenegalia as a distinct genus, these two species had never been treated together as a distinct taxonomic unit, nor had they been included in former major classifications such as those of Bentham (1875) or Britton and Rose (1928) or assigned to an informal species group.

Species of Pseudosenegalia are readily distinguished from those of the more speciose and widespread Parasenegalia by their extremely small leaflets (1-3 × 0.5-1 mm compared with normally (3) 5-18 × 0.5-11 mm in Parasenegalia ), the presence of brachyblasts on branchlets, the absence of anther glands and by a scarious-textured perianth. The latter trait is otherwise unknown in the Senegalia grade. Even in the very large genus Acacia (1082 species), only one species, A. unifissilis Court, is described as having a scarious calyx ( Court 1978).

Taxonomic references.

Seigler and Ebinger (2009, 2018); Seigler et al. (2006a, 2017).

Figures

Figure 192. Morphology of Mariosousa, Parasenegalia and Pseudosenegalia A Mariosousa acatlensis (Benth.) Seigler & Ebinger spicate inflorescences (Seigler 16002) B M. coulteri (Benth.) Seigler & Ebinger bark not papery C M. dolichostachya (S. F. Blake) Seigler & Ebinger branchlet unarmed (Seigler 16035) D-F M. salazari (Britton & Rose) Seigler & Ebinger D exfoliating papery bark (Seigler 16057) E habit F fruits (Seigler 15978) G M. usumacintensis (Lundell) Seigler & Ebinger leaf (Seigler 16027) H Pseudosenegalia feddeana (Harms) Seigler & Ebinger fruits (Atahuachi 1146) I, J Parasenegalia miersii (Benth.) Seigler & Ebinger (Terra, Coutinho & Dalvi 667) I branch showing unusual leaves (i. e., pinnae few and leaflets large) J inflorescences K Pseudosenegalia feddeana contorted tree habit. Photo credits A-G B Maslin H, K CE Hughes I, J V Terra.

Figure 194. Distribution of Pseudosenegalia based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.