Jim, I think the current overlap of Sequoiadendron and Trillium derive from both favoring moist habitats - the affinity goes no deeper. The disjunct populations are likely the result of migration out of the Sierra Nevada through the Transverse and Coastal ranges during the milder, wetter climate of previous ice ages. Of course, there needn't be "migration" at all if both the Sierra Nevada and SLO are themselves relicts of a much broader former distribution. As for Sequoiadendron, I know of no fossil evidence of it occurring near the San Luis Obispo or San Diego County populations. -|<ipp > Date: Tue, 2 Apr 2013 18:16:04 -0700 > From: jamesamckenney@verizon.net > To: pbs@lists.ibiblio.org > Subject: Re: [pbs] ID requested for Trillium cf. chloropetalum > > Dylan, is there fossil evidence of Sequoiadendron in the Coon Creek area - or anywhere between the San Luis Obispo County trillium populations and existing Sequoiadendron populations in the Sierra Nevada? i wonder if those trillium are a relic population from ancient Sequoiadendron forests. > > Jim McKenney > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/