Sir Henry Nicholas Ridley named this begonia species in honour of its discoverer, Dr. F. W. Foxworthy, who was the first chief research officer of the Forest Research Institute (FRI) in Malaya. (It is now named the Forest Research Institute Malaysia or FRIM for short).
Begonia foxworthyi is endemic to Peninsular Malaysia and is distributed in Kelantan, Terengganu, Pahang and Negeri Sembilan. Begonia foxworthyi grows in shaded and damp conditions where it creeps on granite, shale or limestone rocks or on limestone-derived soil in lowland forest.
Foxworthy's begonia has asymmetric leaves with the broadest side of the leaf blade up to 17.5 cm wide. The leaf is plain green or variegated with a light bronzy hue and has a pale red stalk with woolly hairs. Woolly red hairs also densely decorate the leaf margin and undersurface. Flowers with two or four petals gracefully dangle on the inflorescence that emerges from the rhizomatous stem.
Begonia foxworthyi shows several variations in leaf shape, colour, pattern, and in tepal number and colour, and the colour of the ovary. Some variants in leaf shape and pattern are so distinct they would easily confuse beginners in plant identification into thinking they belonged to difference species.
Like all begonias, Begonia foxworthyi is a monoecious plant, having separate male and female flowers on the same inflorescence. Its male flowers bloom before the female flowers so by the time the female flowers are open for pollination, most of the male flowers have wilted and dropped. This natural timing is effective in promoting cross-pollination between plants (xenogamy).
From observations on plants growing in the nursery, we know a mature Begonia foxworthyi plant often has 3-8 inflorescences in different stages of flowering at the same time. Initially its inflorescence will blossom with 15-44 male flowers in a slightly bending position, after about 4 weeks the inflorescence will form 10-15 female flowers in a hanging position due to the weight of the ovary. However, although self-pollination (autogamy) is not possible in unisexual flowers, cross-pollination (geitenogamy, that is, pollination between flowers of the same plant) is possible, because of the availability of inflorescences at different stages so some may have male flowers, while older inflorescences may have female flowers. After fertilization, a Begonia foxworthyi female flower takes about 26 days to form a dry winged fruit capsule with seeds ready for germination.