1. TROPICAL HIBISCUS (ZONES 9, 10);
HARDY HIBISCUS (ZONES 5-8);
others: Hibiscus moscheutos, Hibiscus sabdariffa

http://www.floridata.com/ref/h/hibisc_r.cfm
http://www.geocities.com/~jimclatfelter/hibiscus.html http://edis.ifas.ufl.edu/scripts/htmlgen.exe?DOCUMENT_MG020
http://www.trop-hibiscus.com
http://www.csdl.tamu.edu/FLORA/imaxxmlv.htm

HARDY HIBISCUS - Hibiscus syriacus Zones 5 - 8

http://www.hcs.ohio-state.edu/hcs/TMI/Plantlist/hi_iacus.html
http://members.tripod.com/~h_syriacus/cultivar_list.htm
http://members.tripod.com/h_syriacus/links.htm
http://www.dipbot.unict.it/orto/0067-1.html
http://www.suite101.com/article.cfm/cottage_gardening/9188

DIFFERENCES BETWEEN TROPICAL AND HARDY HIBISCUS

http://www.trop-hibiscus.com/gindr.html

OTHER SPECIES OF HIBISCUS

HIBISCUS MOSCHEUTOS Zone 9 (ssp. palustris; Marvels Zone 5)

http://www.suite101.com/article.cfm/enabling_garden/6434 (link to cultivar Lord Baltimore)
http://www.pp.clinet.fi/~mygarden/hibimos.htm
http://www.msue.msu.edu/msue/imp/modop/00000726.html
http://home.att.net/~SHA-IV/index.htm
http://www.assateague.com/ros-mal.html
Hibiscus x "Lord Baltimore" Rose Mallow (Zone 5)
http://aggie-horticulture.tamu.edu/PLANTANSWERS/96promotions/LordBalt.html
HIBISCUS SABDARIFFA Zone 10