There are many different kinds of Begonias and because of their variety they are classified by their root type.
One of the most popular kinds of Begonias is Begonia Corallina de Lucernaл. Its stem could go higher than 1 m. The leaves are not symmetrical, they are lightgreen with tiny silvery spots If you look at it at a certain light and angle the leaves get coloured in crimson.
You can propagate it by dipping a cluster in water. The plant needs a lot of light and plenty of water. It blooms in pink.