Tom,
There are several types of D.binata in Australia. The basic "T" form
only produces the normal forked twice leaf that you have obviously
observed. The second is the D.binata var dichotoma. These plants
produce up to four forks on each leaf. Anything above this is known a
D.binata var "multifida", which may branch up to 36 times. This gives
the plant a very attractive appearance. I have representatives of all
the D.binata.
Hope this helps,
Russell Elliott