Sep 01 2011
Though it has five petals and sepals, the flower is slightly irregular in shape. The two upper petals have crenellated stripes, the lower three have feathery edges. Together they form a bowl but the bowl is porous. If you pull on a petal you can see that the petals and sepals aren’t connected.
Like many flowers, nasturtiums raise their stamens and pistil at different times in the blooming period. These line up behind the feathery lower petals and force visiting hummingbirds to hover rather than perch. No problem for hummers!
I say “hummingbirds” because the nectar in this flower is inaccessible to bees. It’s not in the bowl but in the long, narrow nectar tube whose entrance is a tiny hole. When I looked at the nectar tube I said “Aha!” It’s the same shape and size as a hummingbird’s bill.
We humans see the nasturtium’s face — and so does the hummingbird — but the real goal is that insignificant tube.
(photo from Wikimedia Commons. Click on the photo to see the original)