That is a pretty good source. Use that for a starting idea of what natives (seems they're not listing non-natives, at least for my area), check outside to see if they are indeed actually in bloom, and then perhaps cross-check with wiki pollen source
for pollen color confirmation.
After a record cold/snowy Winter, we've had quite a few semi-warm (50-60°F) days so far this year. In January-Feb mine were bringing in Hazelnut pollen (orchards are quite close by) and now they are also bringing in Alder and, possibly, the first dandelion. Next the dandelions will really come in with the Willow and Maples and that first black pollen from all the tulips. That's the real start of the season here and then it just accelerates with all the fruit trees, etc.,. Yeah Spring!! I can't wait!