| Wikipedia has a tolerable article on the topic (odd errors here and there, inevitably) Resin |
Here is a link that might be useful: http://en.wikipedia.org/wiki/Pollination
| Some plants produce seed w/o pollenation--- essentially identical to the parent plant. I think Citrus commonly comes true to seed for this reason. |
Here is a link that might be useful: apomictic seed in citrus