Re: Non-aroid query: Ruellia amoena

From: Lester Kallus lkallus at earthlink.net> on 2001.02.23 at 03:57:52(5972) Although I have no idea what this stuff is, I can tell you that I see something that exactly mimics what you've described growing on my Medinilla (the non-aroid plant that aroiders helped identify with just a verbal description). I don't see it on the plant when I grow it outside, but I do see it on the undersides of the leaves and on the stems. I've tasted it and found no taste. I wonder if it's the same thing as on your plant. It sure sounds like it. Les +More At 02:29 PM 2/22/01 -0600, you wrote: >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 > >-- Steve Marak >-- samarak@arachne.uark.edu

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