I guess I took it as a challenge – a friendly one, but a challenge none-the-less. A friend of mine was hanging out in the back museum yard as I was doing a public program about autumn. He happened by at the point where I was asking the families to look for different colored leaves. In particular I wanted them to find at least one yellow one, one red one, a red-speckled one, and a dead brown one since I use these colors to tell an autumn legend. At that point my beneficent tormentor loudly suggested that we should look for something impossible “like a blue leaf.”He plastered one of those “S.E.” smiles across his face as he waited for my reaction. I donned a matching smile and replied “Well, smart aleck, there are some blue autumn leaves but I just don’t happen to want one right now.” He laughed, I laughed and we went about our ways. Unfortunately, I just knew he’d be back at me later to find out what this blue leaf plant was and I would have to back up my statement with a picture.
The autumn leaf landscape is indeed painted with a varied palette, but it favors (not counting the original green shades) the red, orange and yellow end of the spectrum. Blues and violets are left to flower petals and fruits. Now, leaves of Ash, Red-panicled dogwood, Nannyberry and the like do turn a really deep purpley brown but the shade never really leaves the maroon family. There is no way I could argue that a deep maroon leaf was really blue. It had been a while, but I know (at least I was pretty sure) that I’d seen some Nightshade leaves with a beautiful true blue/violet hue in the autumn. The question, however, was if I could actually find one again.
Just in case, I went to the internet to see if I could come up with a picture of one of those blue-leaved Nightshades. Certainly other folks had noticed this. Unfortunately, for a medium that brings us pictures of dogs dressed up in Halloween costumes and portraits of blue frogs, there was not one mention of, or image of, a blue-leaved autumn nightshade. Perhaps my memory was a shade off. I mean, if the internet doesn’t have it – does it truly exist? Thinking that my species memory, not the color memory, was wrong, I tried a lame search for “blue autumn leaves” to turn up something else. No luck. I would have to find my own blue leaf and get a picture of it. I only had a few weeks before I’d have to face my tormentor and produce the goods. Heck, fall itself wouldn’t even last a few more weeks. Maybe I’d have to break out the indigo ink bottle and inject a maple leaf or something!
Just when I had given up all honest resolutions, personal salvation finally came at an unexpected location. While exploring the woodlands across the lake from our West Branch cottage, I shoved through the thick brush that led down to the marshy shore and came upon the remnants of an old beaver canal. There, tucked back among the scrub alders along the edge of the waterway sat a singular blue nightshade (see above and larger version here). This plant was even bluer than I remembered. It fairly glowed in the shade. I got my picture and was satisfied that all my faculties had not yet abandoned me.
The “exotic” plant in question is actually an introduced European plant called the Bittersweet Nightshade. It can become a noxious weed in pastures but it pretty much keeps a low profile. The fact that it requires saturated soils keeps it confined to wetlands. Slightly poisonous, this viney plant produces a chemical called Solonine – a toxin shared by many other members of the Nightshade family such as potatoes, egg plants, and tomatoes (yes, I said tomatoes, but you needed worry since it takes a different form in our garden variety plants). Nightshades produce tiny red fruits that taste so bad that very few things eat it by accident. Though sharing a surname, the Bittersweet Nightshade has nothing to do with the highly toxic Deadly Nightshade of crime & mystery novel fame.
I realize the question remains as to why Nightshades turn blue when no other local plant does. Unfortunately I have no real answer for you or my sarcastic tormentor. Sure, I can say that the hue results from the anythocyanins in the leaf but little else. It does appear to relate to the particular situation in which a plant is growing. Those growing in open sunny areas don’t seem to turn blue while those within shaded situations do. Even on the same plant there are some leaves that take on the hue while others stick to their green & yellows.
As it turned out, I later found a few more of the plants closer to home (frighteningly close to where the initial smart aleck remark was first made). Armed with these photos and the confirmation that not all my memories are false (although I still believe my dad called off a tornado once) I am ready when I next see my nature heckler.