WHAT are these?

I bought them last week at the market under the freeway in Stockton. The man said camotes. I recognized the word, said yeah yeah and forgot about them. But no, these are not Ipomoea batatas (sweet potatoes). Nor are they Jerusalem artichokes or crosnes. Nor oca. Though they are similar to all these. Finger sized. Starchy and sticky and very crunchy raw. Cooked reminiscent of a potato. I still have NO idea what they are. Any ideas?

Dioscorea opposita, aka Chinese yam. a cousin of the true yam. Grated raw is wicked slimy and would indeed make a good sex lubricant. Fried in oil it makes one of the best latkes I've ever eaten. See. It's the base for okonomiyaki! Thanks to my old pal Brian and his wife! You win a recipe for okonomiyaki. Grate these like for latkes, mix in shredded cabbage, scallions, ginger, crushed peanuts and salt. Then fry like a big pancake. If you're not vegan add egg and raw shrimp finely chopped.