Cannabis
Cannabis may be sold in the form of the dried female heads of the plants, and is often referred to as 'bush' or 'green'. It may be combined with tobacco in a 'joint' or smoked on its own in a bong. It can also be brewed into tea or added to cakes to make 'space cakes' or has cookies.
Alternatively the sticky resin may be extracted from the heads of the plants and compressed in to blocks. Similarly 'resin' as its called may be smoked alone, added to a joint, smoked in a wide varieties of pipes (including bongs, chillums and has pipes).
This is a joint ....
... and this is Michael Phelps demonstrating a bong ...