When five is four

Five is the normal number of petals for the flowers of Solanum elaeagnifolium, known as silverleaf nightshade. Five is what every field guide I’ve looked at says. Five is how many petals I’ve always seen in the two decades I’ve known this common Texas wildflower.

Nevertheless, on September 2 at a property along Lost Horizon Dr. that’s getting houses built on portions of it, I found a silverleaf nightshade flower with just four petals. Because of the way adjacent petals in this kind of flower are fused at their edges, it doesn’t seem possible that the specimen started out with five petals and then lost one. Below is a slightly downward view from the other side of the flower that once again clearly shows four 90° angles rather than the expected five 72° angles.

For comparison, here’s the back of a regular silverleaf nightshade flower at the same location.

© 2018 Steven Schwartzman