I have sighted Henckelia platypus numerous times in primary forests of Malaysia and Thailand and it seemed to prefer slopes near the water. This is one of the habitat of the plant, perched on a rocky bank beside the stream. It is supposedly still found in Singapore BTH but it must be very rare now.
It has a trunk up to waist high with a rosette of textured leaves, which in itself would be quite attractive. When in full flowering glory however, the plant is magnificent. The flowers may be white or mauve with yellow stripes at the throat.
There is also smaller relative of this plant growing in my plot which has similar flowers but extremely crinkly leaves. It is very neat - but I have yet to find a name for it since these plants are so little known and literature is scarce.
Cultivation of these interesting gesneriads are not widespread however, as they like hot humid environment which are not easily replicated at home. On top of that, their sensitive foliage is very sensitive to stagnant water and chemicals.