Sour horn (Tamarindus indica Linn): sour horn, also known as sour beans, tamarind, sour plum (Hainan), "Mukhan" (Dai), sweet eye can, through the blood figure, for the family of hematite sour horn of the genus of tropical, subtropical evergreen tree, the genus contains only 1 species of sour horn, there are two types: sweet and sour type. Winter and spring seasons, the sky is high, the wind is clear, into the Daijia village in Xishuangbanna , it is easy to see a local people especially favorite fruit tree - sour horn, evergreen tree, 6 ~ 25m high, diameter at breast height up to 1.6 m. Bark dark gray, into a sheet-like cracking. Branchlets with downy; skin porous, brown. Leaves pinnately compound, leaflets opposite. Panicles terminal or racemes axillary; wood with hard heart, dark red, rounded tender yellow.

Flowers: bisexual, calyx cylindrical-spiral-shaped, apex 4-lobed; petals 5, upper 3 developed, yellow with purplish-red stripes, lower 3 degenerated into scales, stamens 3, united below the middle of the filaments, the rest of the 3-5 degenerated into bristles; gynoecium stalked. The pods are plump, straight or slightly curved, cylindrical, 7-20cm long and 2-3cm wide, with a brown exocarp, thin, brittle and crusty; the mesocarp is thick, fleshy and edible; the fruit is reddish-brown when ripe and has a sour taste; hence its name, "Sour Horn". Seeds yellow-brown, 3-10, nearly oblong, dark red shiny, enclosed in thick mucilaginous mesocarp. Flowering period is from May to June, and the fruiting period is from August to December. It is a tall tree with a rough trunk and sparse foliage, with bunches and bunches of brown, curved, hook-shaped pods 5-12 centimeters long and 1.5 centimeters wide hanging from the branches. There are usually 2-6 fruits in a pod. Flowers in axillary racemes or terminal panicles; calyx tube turbinate, lobes 4, lanceolate; corolla yellow with purplish-red stripes, upper 3 petals well developed, lower 2 reduced to scales; stamens 3, united below the middle of filaments, with 3-5 spiny staminodes; ovary stalked, ovules numerous.

The Cape Sour Tree is an evergreen tree, 6-25 m tall, with dark gray bark that splits irregularly. Leaves even-pinnate, alternate; petiole short and stout; leaflets 14-40, blade oblong, 1-2.4cm long, 4-9mm wide, apex obtuse or retuse, base subrounded, oblique, both surfaces glabrous, entire. Ovules numerous. Pods plump and fleshy, cylindrical, straight or slightly curved, gray-brown, 3-6cm long, about 2cm wide, reddish-brown when the fruit is ripe, with a sour taste. Seeds 3-10, suboblong, reddish brown, glossy. Flowering February-August, fruiting August-December to April of the following year. Sour horn evergreen tree, 6-20 m tall, with dark gray bark, irregularly fissured. Evenly pinnately compound leaves, alternate; petiole short and stout; leaflets 14-40, blade oblong, 1-2.4cm long, 4-9mm wide, apex obtuse or retuse, base subrounded, oblique, both surfaces glabrous, entire.

Sour hornbeam pods are plump and fleshy, cylindrical, straight or slightly curved, gray-brown, 3-6cm long, about 2cm wide, reddish-brown when the fruit is ripe, with a sour taste. Seeds 3-10, suboblong, reddish brown, glossy. Flowering period May-August, fruiting period July-December to May of the following year.