John: Great point. The rate at which speciation occurs certainly affects the loss of winter hardiness in many plants moved around by nature. T. underwoodii could simply be speciating faster than T. lancifolium and therefore loosing it's original hardiness faster. Fred Case also says that that T. underwoodii is the one of the only southern trillium species that causes problems for him in zone 4b for the reason you mention. Another plant from the same area which shows the opposite trait is Baptisia simplicifolia. Even in the Florida Panhandle, it doesn't emerge until June. The emergence date stays virtually the same when it is grown in zone 5. That trait certainly isn't typical for a plant "originally" native to Florida. At 12:22 PM 6/27/2004 -0400, you wrote: >Tony A wrote "Most plants in the Florida panhandle have hardiness to at >least zone 6 and some further north. Originally, many of these plants >resided in the Ohio or Delaware Valleys and were relocated during the last >ice age. They never bothered to lose their winter hardiness." > >But some of them did adapt to their new deep south environment such they no >longer are effectively 'hardy' in zone 6 even though their rhizomes may not >be killed directly. Trillium underwoodii from around Chattahoochee and >Trillium decipiens from a little further north in Georgia are perfect >examples. Their rhizomes are indeed 'hardy' but they have adapted to the >deep south winters and they put up leaves as early as December here in Exton >(zone 6b/7), pretty much irrespective of local climatic conditions. They >seem to respond to a calendar - and of course here this new top growth is >rapidly trashed by temperatures below about 15F. A couple of years of this >and they are no more. It is interesting to note that Trillium lancifolium, >which grows in the same woods as T. underwoodii near Chattahoochee, has >learnt to keeps its head down longer, and so fares better here without >protection. > >J. > > > >_______________________________________________ >pbs mailing list >pbs@lists.ibiblio.org >http://www.pacificbulbsociety.org/list.php > Tony Avent Plant Delights Nursery @ Juniper Level Botanic Garden 9241 Sauls Road Raleigh, NC 27603 USA Minimum Winter Temps 0-5 F Maximum Summer Temps 95-105F USDA Hardiness Zone 7b email tony@plantdelights.com website http://www.plantdel.com/ phone 919 772-4794 fax 919 772-4752 "I consider every plant hardy until I have killed it myself...at least three times" - Avent