!. Not all viruses are causing sickness. Actually most viruses don't and some may be even helpful. 2. It is known that in species crosses sometimes the nucleus does not fit the chloroplast from the other species. This can result in a variegated F1. I have seen this often in cacti. 3. Yes viruses can give stripes too. 4. If it is a virus you must be able to infect another plants by rubbing ( bring fluid from one to the other plant) Ben J.M.Zonneveld Nationaal Herbarium Nederland POBox 9514 2300 RA Leiden, The Netherlands telf 071 5274738 E-mail: Zonneveld@NHN.Leidenuniv.nl