Viguieranthus Villiers, Legum. Madagascar: 271. 2002.

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

Viguieranthus Villiers, Legum. Madagascar: 271. 2002.

Figs 204 , 205 , 207

Type.

Viguieranthus alternans (Benth.) Villiers [≡ Calliandra alternans Benth.]

Description.

Unarmed shrubs or trees to 25 m, with trunks up to 80 cm diameter. Stipules coriaceous, not spinescent, more or less persistent. Leaves bipinnate, rarely pinnate; petioles with an extrafloral nectary at the apex, sometimes also present on the rachis tips, sometimes the petioles and rachis with narrowly winged margins; pinnae of bipinnate leaves 1 pair; leaflets alternate to opposite, sometimes 1 or 3 per pinna, 1 pair per leaf in pinnate leaves, up to 7.7 × 4.6 cm, but frequently more numerous (to 34 per pinna), and smaller (9-35 × 2-15 mm). Inflorescences spherical heads, elongate spikes or racemes, pedunculate, solitary or fasciculate, arising from leaf axils, sometimes organised in pseudopanicles, homomorphic. Flowers hermaphrodite; calyx usually cup-shaped, less frequently broadly obovoid, obconical or hemispherical, 4-5-lobed; corolla obconical, with the petals connate into a tube, 4-5-lobed; stamens numerous, long exserted from the corolla, white, always with the base fused forming a tube inserted in the corolla, anthers eglandular; pollen in 16-grained polyads, acalymmate, discoid, heteromorphic, without eccentric lens-shaped thickenings on the central cells; ovary sessile or short-pedicellate; stigma funnel-shaped or capitate. Fruits linear-oblanceolate, linear-elliptic, or linear-obovate to narrowly obovate, flattened, straight or slightly curved, with thickened margins, the valves chartaceous, coriaceous or ligneous, dehiscing along both margins. Seeds ovoid, oblong or rhomboid, without a pleurogram.

Chromosome number.

Unknown.

Included species and geographic distribution.

Eighteen species occurring in Madagascar, all endemic (except V. subauriculatus Villiers also recorded from Comoro Islands) (Fig. 207 ).

Ecology.

Most species are reported from the eastern, humid, evergreen forests in Madagascar. However, some species grow in areas covered by dry deciduous woodland or xerophytic scrubland. Populations are reported from sea level to 1600 m ( Villiers 2002).

Etymology.

Named after René Viguier (1880-1931), French botanist.

Human uses.

The wood of some species is reported to be used as firewood, and for house construction and joinery ( Villiers 2002).

Notes.

In the original description of Viguieranthus , published in The Leguminosae of Madagascar one year after J.F. Villiers’ death ( Villiers 2002), it was mentioned that the genus comprises 23 species distributed in Madagascar and Asia. However, only 18 species were considered, including new combinations and new species. As concluded by Souza et al. (2016), the five remaining species not considered by Villiers correspond to five Asian species: three currently recognised under Thailentadopsis ( Lewis and Schrire 2003); to Calliandra cynometroides Bedd., later transferred to Sanjappa ( Souza et al. 2016); and C. umbrosa (Wall.) Benth., one species from India, Bangladesh and Myanmar. The latter species certainly does not belong to Calliandra in its current concept (see Calliandra clade, page 358), and its generic placement is awaiting critical evaluation4.

In light of the previous considerations, Viguieranthus is a Madagascan genus, characterised by constantly having leafy (not spinescent) stipules; bipinnate leaves with only 1 pair of pinnae; a variable number of opposite or alternate pairs of leaflets per pinna, sometimes reduced to one leaflet per pinna ( V. unifoliolatus Villiers and V. brevipennatus Villiers); and homomorphic inflorescences ( Villiers 2002). The polyads, described as Type A polyads by Guinet and Hernández (1989), are 16-grained, acalymmate, discoid, heteromorphic, and lack the eccentric, lens-shaped thickenings on the central cells, characteristic of Zapoteca . Viguieranthus is probably a monophyletic genus (further sampling is required; Souza et al. 2013, 2016) and sister to a clade that includes Faidherbia , Sanjappa and Thailentadopsis ( Ringelberg et al. 2022).

Taxonomic references.

Villiers (2002).

Figures

Figure 204. Morphological features of the Zapoteca clade A, B Faidherbia albida (Delile) A. Chev. A habit B leaves C, D Sanjappa Calliandra cynometroides (Bedd.) E. R. Souza & M. V. Krishnaraj C habit D pinnate leaves and inflorescence in bud E Zapoteca aculeata (Spruce ex Benth.) H. M. Hern. foliage and inflorescences at anthesis (Neill 18437) F Zapoteca formosa subsp. schottii (Torr. ex S. Watson) H. M. Hern. habit and dehisced fruits G Viguieranthus glaber Villiers leaves and inflorescences post-anthesis. Photo credits A Gobabeb - Namib Research Institute B Dave U C, D G Suresh E D Neill F D Beckman G C Davidson.

Figure 205. Inflorescence and fruit morphology in the Zapoteca clade A, B Faidherbia albida (Delile) A. Chev. A inflorescences at anthesis B indehiscent fruit C, D Sanjappa Calliandra cynometroides (Bedd.) E. R. Souza & M. V. Krishnaraj C inflorescence post-anthesis D pinnate leaves and immature fruit E Thailentadopsis tenuis (Craib) Kosterm. inflorescence F Viguieranthus perrieri (R. Vig.) Villiers inflorescence at anthesis G Viguieranthus alternans (Benth.) Villiers foliage and fruits before dehiscence H Viguieranthus brevipennatus Villiers inflorescence at anthesis (Randrianarivony 175) I Zapoteca tetragona (Willd.) H. M. Hern. inflorescence at anthesis J Zapoteca portoricencis (Jacq.) H. M. Hern. subsp. portoricensis inflorescence at anthesis (Amith 74438) K Zapoteca formosa subsp. schottii (Torr. ex S. Watson) H. M. Hern. dehisced fruit. Photo credits A S Piry B B Adkins C, D G Suresh E https: // marketingoemoffice. com / Data _ Pithecellobium. html F F Ratovoson G F Rakotoarivony H T Randrianarivony I FJ Gomez Marin J J Amith K D Beckman.

Figure 207. Distribution of Viguieranthus based on quality-controlled digitised herbarium records. See Suppl. material 1 for the source of occurrence data.