The multicoloured flowers of Mirabilis jalapa (pronounced, invariably, in England with a J :) ), in whatever form they are (i.e several colours in one flower or different coloured flowers on the same plant), are caused by transposons or jumping genes. See Wikipedia for further info on how they work. Essentially they cause mini-mutations during the colour production process. Jim Waddick mentioned Ipomoea 'Flying saucers' and roses as other plants with similarly flaky flowers, but one could add Geranium pratense 'Striatum' and various antirrhinums to the list. Other factors causing variation in flower colour may be virus, as in tulips (which probably works in much the same way as transposons) and possibly tissue chimaeras. John Grimshaw Dr. John M. Grimshaw Sycamore Cottage Colesbourne Cheltenham Gloucestershire GL53 9NP Tel. 01242 870567 ----- Original Message ----- From: "piaba" <piabinha@yahoo.com> To: <pbs@lists.ibiblio.org> Sent: Sunday, September 14, 2008 8:04 PM Subject: [pbs] Mirabilis jalapa > but, john, what causes this phenomena? the ones that produce both color > flowers are in one particular corner. all others i have seen are just > magenta-flowered. is it a virus like the streaked tulips? > > ========= > tsuh yang > > > > > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://www.pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ -------------------------------------------------------------------------------- No virus found in this incoming message. Checked by AVG - http://www.avg.com/ Version: 8.0.169 / Virus Database: 270.6.21/1671 - Release Date: 14/09/2008 07:16