PlantaeDB Logo
Login Sign-up

Genus Mariosousa in Subfamily Caesalpinioideae

In botanical taxonomy, a genus (plural genera) is a rank used to group closely related species within a family. In the hierarchy, genus sits below family and above species.

Genera are defined by shared morphological, anatomical, and genetic characteristics (for example, features of flowers, fruits, seeds, or leaves) that indicate a close evolutionary relationship among the species they contain.

Each genus can include one or more species. Examples include Rosa (roses) and Solanum (nightshades, including tomato and eggplant).

Do you wish to read more about plant taxonomy? Click here!

Genus Description

Suggest a correction!

Mariosousa (Acaciinae, Fabaceae) comprises approximately 12–13 species of trees and shrubs native to the Mexican highlands and northern Central America, with centers of diversity in the Balsas Depression, Sierra Madre Occidental and Oriental, and the Trans-Mexican Volcanic Belt (Seigler & Ebinger, 2006; Miller et al., 2017; POWO, 2024). The genus was segregated from the former “Acacia” sensu lato to reflect the molecularly defined clade containing the New World Acacia species with bipinnate leaves and spicate inflorescences (Seigler & Ebinger, 2006). Mariosousa millefolia (Vahl) Seigler & Ebinger is generally cited as the type species (POWO, 2024). Most members are thornless trees with corky or warty branchlets; leaves are bipinnate with one to several pairs of pinnae, minute or caducous stipules, and numerous small leaflets; inflorescences are spikes or spikes in panicles; flowers are bisexual with a gamosepalous calyx, 5 united petals, numerous exserted stamens, and a superior ovary; the fruit is a dehiscent pod or sometimes constricted between seeds (Seigler & Ebinger, 2006). Diversity is centered in seasonally dry tropical forests, thorn scrub, and riparian woodlands between roughly 600 and 2,200 m; M. centralis and M. digitifera exemplify the northwestern and southern Mexican distributions, while M. millefolia extends into the Yucatán Peninsula, and M. mollis reaches Central America (Seigler & Ebinger, 2006; GBIF, 2024).

Pollination is primarily entomophilous and dispersal is by endozoochory; seeds are strophiolate and arillate, a feature associated with myrmecochory in the Acacia alliance (Le Roux et al., 2018). Chromosome counts are not consistently reported; a base number of x = 26 has been proposed for the Acacia alliance but remains tentative for Mariosousa (Dabrowska, 1995). Taxonomically, Mariosousa is widely accepted as distinct from Senegalia (most New World Acacia with capitula or phyllodia) and Vachellia (species with paired stipular spines), although some treatments retain these groups within Acacia (Maslin et al., 2003; Butcher et al., 2013). Recent revisions have reduced species numbers through synonymization, for example M. centralis now includes M. tehuacana (Pedraza-Negrete & Ojeda-Durán, 2022). Several taxa remain poorly differentiated morphologically, and genetic sampling remains incomplete relative to Vachellia and Senegalia (Miller et al., 2017).

Species are occasionally used locally for fuelwood, shade, and live fences; the genus contributes to restoration plantings for degraded drylands but is not a major commercial timber or ornamental group (Seigler & Ebinger, 2006). Most taxa are widespread and common, although region-specific declines in dry forest cover are evident in parts of western and central Mexico (Maslin et al., 2003). Targeted population monitoring and integrative taxonomy are required to clarify species limits and conservation priorities.

Pick a Species to see its components: