Tuber oregonense (on the left) has an opaque peridium that develops prominent reddish-orange tints
and fissures as it matures. Their season is from October through February. On the right, Tuber gibbosum
has a very thin, almost translucent peridium. It can have some reddish tones but they are not nearly as
predominent as in T. oregonense The fruiting season of T. gibbosum is from February through June.