The Plant Kingdom is incredibly diverse, and although relatively few species are suitable for use indoors they still provide a wide range of shapes, colours, textures and styles that can be used in a variety of indoor environments.  For practical purposes these could be described as follows:

Jungly plants with large amounts of lush, glossy foliage. Often with big leaves and an informal habit.
Bushy palm plants with a bushy habit and no defined trunk. Fronds grow from stems that emerge straight from the ground.
Tree-shaped plants with a defined trunk and dense crown of foliage.
Palm-shaped plants with long trunks and a crown of foliage emerging from the top.
Trailing / climbing plants that climb up frames or trail over edges. They may require some support or a structure around which to grow.
Bushy plants with dense foliage but no defined trunk. The foliage may be on many stems or appear straight from the ground.
Ground-cover plants with a spreading habit ideal for covering bare soil in landscape beds.
Spiky plants that have a spiky habit.
Upright plants that have an upright habit with little spread.

Try to find plant species that fit into each of the above categories by going to the Specifiers’ Guide.