Senna rizzinii

Senna rizzinii is a scandent shrub with tomentose, inermous branches. The plant features lateral, acicular stipules and paripinnate leaves with four opposite, lanceolate leaflets. The venation is brochidodromous, and there is no translucid punctuation. The inflorescence is a terminal and axillary raceme with pedicellate, zygomorphic flowers. The calyx is dialysepalous with five sepals, and the corolla is dialypetalous with five yellow petals. The androecium is dialystaminous and heterodinamous, with poricidal anthers. The ovary is superior, sessile, and pluriovulate. The fruit is a stipitate, linear, cylindrical berry with a straight margin and a tomentulose, brown epicarp. The seeds are obovate, plane, with a black coat and a basal hilum.

Senna rizzinii is found in the semi-arid region of northeastern Brazil, particularly in the state of Paraíba. It thrives in conservation units within this arid environment, where it likely plays a role in local ecosystems by contributing to plant diversity and providing resources for pollinators and seed dispersers.

Cultivation of Senna rizzinii is not well documented, but given its native habitat, it likely requires well-drained soils and a dry, warm climate. As a member of the Fabaceae family, it may have the potential to fix nitrogen, which could be beneficial in arid or degraded soils. Propagation could be attempted through seeds, though specific germination requirements are not known.

Currently, there are no known economic or traditional uses of Senna rizzinii. However, as a member of the Senna genus, which includes species used in herbal medicine and as ornamental plants, there may be potential for future research into its medicinal properties or horticultural value. Its ecological role in the semi-arid regions of Brazil may also be significant in terms of biodiversity conservation.