Huisachillo

Perennial, Shrubs, Woody throughout, Nodules present, Stems or branches arching, spreading or decumbent, Stems less than 1 m tall, Stems 1-2 m tall, Trunk or stems armed with thorns, spines or prickles, Stems solid, Stems or young twigs sparsely to densely hairy, Stems hairs pilose or spreading, Leaves alternate, Leaves petiolate, Extrafloral nectary glands on petiole, Stipules inconspicuous, absent, or caducous, Stipules spinose or bristles, Leaves compound, Leaves bipinnate, Leaf or leaflet margins entire, Leaflets alternate or subopposite, Leaflets 10-many, Leaves glabrous or nearly so, Inflorescences racemes, Inflorescences globose heads, capitate or subcapitate , Inflorescence axillary, Bracts very small, absent or caducous, Flowers actinomorphic or somewhat irregular, Calyx 5-lobed, Calyx glabrous, Petals united, valvate, Petals white, Stamens numerous, more than 10, Stamens completely free, separate, Stamens long exserted, Filaments glabrous, Style terete, Fruit a legume, Fruit unilocular, Fruit tardily or weakly dehiscent, Fruit elongate, straight, Fruit exserted from calyx, Fruit compressed between seeds, Fruit hairy, Fruit 3-10 seeded, Seed with elliptical line or depression, pleurogram, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black.

Vachellia tortuosa, the twisted acacia , poponax or huisachillo, is a woody, leguminous thorn tree of the Caribbean, Florida, southern Texas, northeastern and central Mexico, and northern South America. It is found in tropical and desert habitats, such as the Rio Grande Valley, Central Mexican Plateau, and Colombian Tatacoa Desert.