Question
The truffle (the part you eat) does not rise above ground to spread its spores.
What is its function and what scientific name does the part you eat have? Thank you.

Answer
Truffles are fungi, not plants, but I happen to know a little about them.  The part you eat is the fruiting body, or the spore containing structure.  It just doesn't rise above the soil like other fungi.  In truffle fungi, the fruiting body is called an ascoma.

Trey