You must be lost

Last year, I made a resolution to use at least one vegetable-type ingredient per month that I had never cooked with before. I think I made it to March with red and yellow beets, chayote, and yucca root. There may have been others I inadvertently added throughout the year, but I didn't mentally take stock of them as counting towards my goal of 12 new ingredients.

I'm going to attempt it again this year and hopefully with more success. This month (well, tonight actually): spaghetti squash. I found a Southwestern casserole-type recipe that sounds really tasty and above all, really easy. It seems pretty retarded actually that I've not cooked or even eaten spaghetti squash before. I've liked every other type of squash I've tried, why not this one? In fact, I think this is the last type of readily available winter squash that I've not tried.

Also on the list:
Brussels Sprouts - because I recently found out I like them when they're prepared well
Swiss Chard
Broccoli Rabe
Jicama

Then I'm going to have to do some research.

ETA: Suggestions from arymetore:
kohlrabi
cassava
salsify (if it can be found)
sorrel
prickly pear

ETA2: One I thought of while in the grocery earlier:
Celeriac

And with that, I'm almost to 12, but I will keep looking for more. I think having them in mind ahead of time will be helpful. Maybe I need to go wander around Whole Foods.