Non-aroid query: Ruellia amoena

From: Steve Marak samarak at arachne.uark.edu> on 2001.02.22 at 20:28:19(5968) I hope you will forgive this breach of aroidal relevance (made worse by my being one of the listowners!); I spent some time trying to decide where to post this, concluding it didn't fit on any list to which I belong. But I know there are many people on Aroid-L who grow many things beside aroids, and who have incredibly wide-ranging knowledge, and I know several of them grow this plant. Seven or eight years ago, Phil Mueller sent me a piece of a ruellia which he said "grew all over the place" in New Orleans to see the bright red flowers. I rooted the piece and have been enjoying it ever since. I tentatively identified it as R. amoena (for a close-up of a flower, see: http://www.csdl.tamu.edu/FLORA/mi14/mi14048.jpg or of the entire plant: http://www.csdl.tamu.edu/FLORA/mi14/mi14047.jpg ) Though not hardy here, and a bit sprawly, and of course being a ruellia it shoots seeds everywhere, I like it - it's in full flower now, and it's a real bright spot in the greenhouse. But one mystery I haven't solved: what is that stuff that forms all over the leaves when it's inside for the winter? And why does it form? And does it do that for anyone else who grows it? It's a white substance, maybe very very slightly sticky but mostly just feels gritty, forms on both surfaces of the leaves, doesn't seem to be there when the plant is outside in summer (or maybe it's just washed away by the sprinkler), doesn't seem to be contagious, and doesn't seem to do the plant a bit of harm. It wasn't apparent when the lopped-off piece arrived, but appeared within a month or two. When I bring the plant(s) in in the fall, it's not present but appears within a couple of months at most. Although it didn't look like any of the usual insect pests to me - mealybugs, scale, spider mites (and being nearsighted, spider mites are usually perfectly visible to me), etc. - my initial assumption was "something bad". But as I say, there seems to be no harm to the plant - no loss of vigor, or color - and it doesn't spread to anything nearby. Today, having some time, I started with a magnifying glass, working past 20x hand lens up to a cheap microscope. Best results seem to be at 50-100x, where it appears to be almost crystalline in nature. It has no detectable smell or taste to me, although one of my cats seems interested in it (but doesn't eat the plant). It certainly doesn't look insect-like in any way. Does anyone have any ideas? Thanks, Steve +More -- Steve Marak -- samarak@arachne.uark.edu

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