Annona tomentosa is a species of plant in the family Annonaceae. It is native to Bolivia and Brazil.[1] Robert Elias Fries, the Swedish botanist who first formally described the species, named it after the dense woolly hairs (Latin: tomentosus in Latin) covering its branches and leaves.[2]
It is a bush reaching 0.5-1.5 meters in height. The younger branches are covered in yellow-brown, dense, woolly hairs. Its internodes are 1-4 centimeters long. Its petioles are 3-4 millimeters long and covered in dense woolly hairs. Its oblong to oval leaves are 7-19 by 3.5-9 centimeters. The leaves are rounded or indented at their base and come to a tapered point at their tip. The leaves are covered in dense hair on their upper and lower surfaces. The leaves have 8-18 secondary veins emanating at an acute angle from either side of the midrib. Inflorescences emerge between nodes and have 1-2 flowers. Its pedicels are 1.5 centimeters long and have two kidney-shaped bracts that enclose their base. Its rounded sepals come to a point at the tip, are covered in dense woolly hairs on their outer surface, and are hairless on their inner surface. Its outer petals are 1.7 by 2 centimeters and come to a taper point or have blunt tips. The outer surfaces of the outer petals are covered in dense grey-yellow hairs. Its inner petals are 0.6-0.7 by 2 centimeters, have a keeled back and come to a point at their tip. Its stamens are 3 millimeters long. Its ovaries are covered in dense white hairs.[3]
The pollen of Annona tomentosa is shed as permanent tetrads.[4] Pollinators include Cyclocephala beetles.[5]
It has been observed in fields with dry sand dunes.[3]
It is used in Brazilian traditional medicine and extracts from the leaves have been reported to provide antinociceptive pain relief and have anti-inflammatory activity in studies with mice.[6]