The first week in May 2010 will be Iowa Native Plant Society's first Iowa Wildflower Week. Events are listed here. When I find a geocache (with kids or alone), being able to identify wildflowers has enriched my hiking. Maybe it's the way I grew up, but nature has always had a prominent place in my life. I see Iowa Wildflower Week as a great way to celebrate our spring ephemerals.
There are two Tuesday evening events. One at Margo Frankel Woods, home to GC19164 Back in Black and GC1Q3FR The BarnStormer and another at Jester Park. Jester Park Lodge has no nearby caches, but the park is home to several geocaches. I like to go early to event sites for some geocaching, and I make sure to photograph any unknown flowers. I look them up later with my field guides. I also keep a lifelist, which I'll discuss in the future.