Tridactyle gentilii is usually an epiphytic orchid that grows stems to 80 cm. The stems become pendent with age as mature plants form tangled masses. The roots are smooth, up to 4 mm in diameter. Numerous leaves are grown that have unequally bilobed tips. The leaves become up to 20 cm long.
The inflorescences have from 7 to 15 flowers each. The flowers are white, pale green or cream and strongly fragrant. The sepals are oblong to obovate with obtuse tips, up to 9 mm long and 5 mm wide. The lateral sepals are oblique, the tips of all three curve back. The lateral petals are linear to lanceolate, 9 mm wide and 2 mm wide.
The lip is three-lobed, the lateral lobes longest and fringed at their tips. The spur becomes up to 8 cm long. The column is only up to 3 mm long.
The pollinators are probably moths. Flowering happens in spring and summer.
The species is distributed from KwaZulu-Natal into tropical Africa as far as Uganda and Ghana. The habitat is wet woodland to elevations of 2200 m in high humidity. The species is not considered to be threatened in its habitat early in the twenty first century (www.africanorchids.dk; www.orchidspecies.com; www.redlist.sanbi.org).