Here are some of the most common tinders around me (Midwest) weather permitting.
Left to Right: goldenrod, thistle, milkweed ovum, cattail, and a birds nest (happened to come by an old one)
Some of these are flash tinders meaning that you better have a secondary tinder ready right quick. They will all work charred except for goldenrod, I cannot get goldenrod to take a spark but it burns long and hot when in the raw, go figure. I also have some cedar for inner bark but many trees will provide useful inner bark.
Now I'll share my big secret with you all... you don't need to look for tinder regardless of the conditions. There is ALWAYS dry tinder right under your nose. Inner heartwood scrapings from any standing dead wood will provide everything you need for a fire including tinder, kindling, and fuel. Just split it down to get to the inside and scrape the blade of your knife at a 90 degree angle to make fine scrapings (not feathers, that's the next step).
The following picture is a test of some wood I was experimenting with, there should be a much larger pile to start a fire but that wasn't the intent here.