Tools for the conservation of the threatened species, var. .

conservation is critical for hedging against the loss of plant diversity. For those species (exceptional species) that cannot be conserved long-term in standard seed banks, alternative methods are required, often involving culture and cryopreservation, or storage in liquid nitrogen. var. is a federally threatened perennial native to Utah and Arizona. It is classified as an exceptional species, because it produces few seeds, and, thus, propagation and cryopreservation were investigated as tools for its propagation and preservation. Shoot-propagating cultures were established from both seedling and wild-collected shoots, but cultures from both sources displayed an extreme form of the physiological disorder, hyperhydricity. This phenotype could be at least partially normalized by the use of vented closures, as well as by using agar, rather than gellan gum, in the medium. The hyperhydric (HH) phenotype had a lower dry weight, more branching, minimal leaf development and more poorly developed vascular tissue than the more normal (MN) phenotype. Only more normalized shoots could be rooted and the resulting plants acclimatized. Both HH and MN shoots also provided shoot tips capable of surviving cryopreservation using the droplet vitrification method. These and cryopreservation methods provide tools that can be used for propagating plants of var. for research and restoration, as well as for supplying shoot tips for the conservation of this species. The two distinct phenotypes also provide a useful system for studying factors involved in the HH response of this dryland species .