Mimosa arenosa
(elegant mimosa)

Preferred Common Name

• elegant mimosa

Other Scientific Names

• Acacia arenosa Willd.
• Acacia malacocentra Mart.
• Mimosa malacocentra (Mart.) Benth.
• Mimosa xantholasia Benth.

International Common Names

• Spanish: tepehuiste

Local Common Names

• Brazil: calumbí; calumbí-de-vaqueiro; jurema-branca
• Mexico: cucharita de cerro
• Nicaragua: tepehüiste
• Venezuela: cují y narauli; cujicillo; ñaragato; ñarauli

• Domain: Eukaryota
•     Kingdom: Plantae
•         Phylum: Spermatophyta
•             Subphylum: Angiospermae
•                 Class: Dicotyledonae
•                     Order: Fabales
•                         Family: Fabaceae
•                             Subfamily: Mimosoideae
•                                 Genus: Mimosa
•                                     Species: Mimosa arenosa

Fabaceae is one of the largest families of flowering plants. This family includes about 766 genera and 19,580 species growing in a great variety of climates and habitats worldwide (Stevens, 2017). Mimosa is a monophyletic genus within the subfamily Mimosoideae comprising about 540 species, most of which (~490 species) are native to the Americas. Mimosa species are recognized by a set of characters including bipinnate leaves with sessile leaflets, spicate or capitulate inflorescences of trimerous to pentamerous flowers, haplostemonous or diplostemonous androecia with white, pinkish or yellow filaments, and anthers without apical glands (Simon et al., 2011; Dourado et al., 2013; Stevens, 2017). The most recent classification of Mimosa proposed by Barneby (1991) divided the genus into five sections, 41 series and 37 subseries.

Thorny shrub or tree, usually 3 to 5 m (up to 12 m) in height. Stem diameters of 15 cm or more. Young and undisturbed plants have a single stem that may branch several times near the ground. As trees become older and heavier, they tend to lie down and produce new, vertical sprouts. Stems are covered by dark brown, shallowly furrowed bark. The inner bark is green. Twigs are greenish brown with 3 to 4 mm, curved spines. The alternate, compound leaves commonly have 4 to 22 pinnae each with 15 to 35 pairs of leaflets. Inflorescences are 6 cm spikes with paniculiform branching bearing many tiny, white flowers. The fruits, which are borne in clusters, are linear-oblong, flat, brown legumes, 4-5 cm by 5-6 mm in size. The seeds are yellow, flattened, and are approximately 4.5 mm by 5 mm in size (Francis, 2004).

In Venezuela and Brazil, the leaflets of M. arenosa vary from glabrous ciliolate to pubescent on both faces. In Brazil pubescent leaflets seem to occur only locally in north-central Minas Gerais and are commonly accompanied by cauline aculei curved upward. In arid zones in northeastern Colombia and northwestern Venezuela the species is represented by plants in which the leaf-formula is quite plastic and leaflets include glabrous and villosulous forms (Barneby, 1991). 

Soil drainage

• seasonally waterlogged

Soil reaction

• acid
• neutral

Soil texture

• heavy
• light
• medium

M. arenosa is a fast-growing weedy species that rapidly forms thorny and almost impenetrable thickets that inhibit the germination and establishment of seedlings of other species, including native plants, and alter natural successional patterns. It is also an aggressive invader of abandoned pastures, rangeland, and disturbed open areas. As a nitrogen-fixing species, M. arenosa has the potential to change soil nitrogen levels, impacting nutrient balances and cycling in invaded areas (Francis and Liogier, 1991; Francis, 2004; Romero-Duque et al., 2007; Joseph and Abati, 2016).

M. arenosa forms dense thickets that alter successional processes and outcompete native plant species, with a consequent reduction in native biodiversity. Across the Caribbean islands (i.e., Puerto Rico and Martinique), this species is invading mostly disturbed sites within dry forest, one of the most threatened ecosystems in the world (Murphy and Lugo, 1986; Francis, 2004; Romero-Duque et al., 2007; Joseph and Abati, 2016).

• Proved invasive outside its native range
• Abundant in its native range
• Highly adaptable to different environments
• Is a habitat generalist
• Tolerates, or benefits from, cultivation, browsing pressure, mutilation, fire etc
• Pioneering in disturbed areas
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Gregarious

• Altered trophic level
• Modification of nutrient regime
• Modification of successional patterns
• Monoculture formation
• Reduced amenity values
• Reduced native biodiversity
• Threat to/ loss of endangered species

• Competition - monopolizing resources
• Rapid growth
• Produces spines, thorns or burrs

Within its native distribution range, M. arenosa is occasionally used for restoration of degraded habitats. The leaves and fruits are widely used as fodder for cattle and goats, especially in the dry season when there is no pasture. The wood is used used as firewood and fencing stakes (Francis, 2004; Grandtner and Chevrette, 2013).