Question
I'm trying to grow a wild black seeded anise that is extremely more flavor than the commercial green varieties and endangered in the wild. There is next to nothing available concerning propagation.  One of the few black anise plant I've managed to grow has produced seed. I read that green anise( a different species) requires cross pollination.  I can't belive i don't know this and can't find the answer easily but do plants that require cross pollination not produce seed or do they produce non-viable seed.

Answer
Hi Ronald,
Thanx for your question.  In general, plants that cross-pollinate will produce seed which results in a hybrid of the two.  Occasionally, the seed will be sterile or the the ovaries will fail to produce seed.

Green anise is also simply known as anise (Pimpinella anisum).  There is also Anise Hyssop (Agastache foeniculum).  Black anise is also Pimpinella anisum.  A lot of plants are not self-pollinating so more than one plant would be required in order to produce seeds.  Anise requires pollination by bees or other insects which may be where you got the reference regarding cross pollination.  One reference I read indicated that "black anise" only grows in the Calabria region of Italy and so is very difficult to find in the U.S.  I know nothing about this.  

I hope this helps.
Tom