Tissue culture propagation protocols have been developed at CREW (Cincinnati Zoo & Botanical Garden) and have been used to initiate in vitro cultures of multiple genotypes. These are being used to provide plants for ex situ living collections at the Arboretum at Flagstaff and at the CZBG.

Tissue culture propagation protocols have been developed at CREW (Cincinnati Zoo & Botanical Garden) and have been used to initiate in vitro cultures of multiple genotypes. These are being used to provide plants for ex situ living collections at the Arboretum at Flagstaff and at the CZBG.

Tissue culture propagation protocols have been developed at CREW (Cincinnati Zoo & Botanical Garden) and have been used to initiate in vitro cultures of multiple genotypes. These are being used to provide plants for ex situ living collections at the Arboretum at Flagstaff and at the CZBG. Shoot tip cryopreservation protocols have also been developed and genotypes initiated into culture are also being cryopreserved and stored in liquid nitrogen in CREW's CryoBioBank. Shoot tips showed good survival after 13 years of storage in liquid nitrogen. Since there are few or no seeds produced by H. todsenii, shoot tip cryopreservation provides an alternative method for long-term ex situ conservation for this species (Pence et al., 2009; Pence et al., 2017). Research on improving in vitro growth and rooting of H. todsenii is continuing at CREW. Research on cryopreservation protocols for shoot tips of this species has shown improved survival using droplet vitrification, compared with encapsulation dehydration and encapsulation vitrification (Pence et al., 2017).

Research on improving in vitro growth and rooting of H. todsenii is continuing at CREW.  Research on cryopreservation protocols for shoot tips of this species has shown improved survival using droplet vitrification, compared with encapsulation dehydration and encapsulation vitrification (Pence et al., 2017).  Genetic analysis of shoot tips after up to 13 years of storage in LN showed little change (Pence et al., 2027).  Despite the lack of seed production, H. todsenii populations do show some genetic diversity (Pence et al., 2009; Philpott et al., in prep.).  Further genetics work is underway at CREW to guide collecting and ex situ conservation of shoot tips (Philpott et al., unpubl.).

Tissue culture propagation protocols have been developed at CREW (Cincinnati Zoo & Botanical Garden) and have been used to initiate in vitro cultures of multiple genotypes.  These are being used to provide plants for ex situ living collections at the Arboretum at Flagstaff and at the CZBG.  Shoot tip cryopreservation protocols have also been developed and genotypes initiated into culture are also being cryopreserved and stored in liquid nitrogen in CREW's CryoBioBank.  Shoot tips showed good survival after 13 years of storage in liquid nitrogen.  Since there are few or no seeds produced by H. todsenii, shoot tip cryopreservation provides an alternative method for long-term ex situ conservation for this species (Pence et al., 2009; Pence et al., 2017).

This edaphic species is known from 32 locations in the San Andres and Sacramento mountains of south central New Mexico. The plants are locally abundant but restricted to limited suitable habitat. The plants primarily spread by cloning, but also by limited sexual reproduction.

Natural threats currently appear to be greater than threats from human activities, because populations are relatively inaccessible. Grazing by livestock and wild ungulates impacts plants, but drought is probably a more serious threat.

18 populations are found on federal lands in the San Andres and Sacramento Mountains of New Mexico.

In an attempt to determine if genetic or pollination factors were limiting seed set in the wild, Huenneke (1993) did pollination and genetic studies of Todsen's pennyroyal, however the genetic results do not clearly explain patterns of poor seed set seen in the wild.

Todsen's pennyroyal habitat on BLM-lands has been recommended for designation as an Area of Critical Environmental Concern. On USFS lands, the plant's habitat is not authorized for logging or fuelwood harvest and the grazing allotment has been withdrawn.

More research is needed on factors responsible for low sexual reproduction.

The species has been successfully propagated vegetatively through traditional and tissue-culture techniques, however because no or few seed is produced in the wild, plants can only be kept ex situ through vegetative propagation.