Here are some things I found at this site regarding oxalic acid content:
Pretty much nothing is oxalic-free...this should be a good chart to compare levels in different foods.
Vegetable Oxalic acid
(g/100 g)
Amaranth 1.09
Asparagus .13
Beans, snap .36
Beet leaves .61
Broccoli .19
Brussels sprouts .36
Cabbage .10
Carrot .50
Cassava 1.26
Cauliflower .15
Celery .19
Chicory .21
Chives 1.48
Collards .45
Coriander .01
Corn, sweet .01
Cucumbers .02
Eggplant .19
Endive .11
Garlic .36
Kale .02
Lettuce .33
Okra .05
Onion .05
Parsley 1.70
Parsnip .04
Pea .05
Pepper .04
Potato .05
Purslane 1.31
Radish .48
Rutabaga .03
Spinach .97
Squash .02
Sweet potato .24
Tomato .05
Turnip .21
Turnip greens .05
Watercress .31
Taken from this website: http://www.nal.usda.gov/fnic/foodcomp/Data/Other/oxalic.html
Thanks for giving me that link to check out! I appreciate it!