Ligusticum porteri

Ligusticum porteri is very similar to, but clearly distinct from, L. filicinum. L. porteri has leaves with broader ultimate segments and the terminal umbel is usually subtended by a whorl of 3-8 lateral umbels, and occasionally with up to 12 or more umbels. In unusual cases there may only be two lateral umbels but then they are always opposite and not alternate. The similarity between these two species has led to confusion as to the range of L. porteri in Utah (Welsh et al. 1993).

Apparently the common name, osha, is also applied to Ligusticum canbyi, which may also be collected for medicinal purposes (Tilford 1997).

Ligusticum porteri is found over a relatively wide range and is relatively abundant. However, substantial commercial exploitation is evident. The absence of cultivation to meet the needs of the growing herbal industry is a concern. Collection now must meet the needs of not only the local herbal stores and individual healers but also of national and international markets. If the present commercial demands continue at the same level, or increase, it is likely that some populations of Ligusticum porteri will be in jeopardy of extirpation.

Ligusticum porteri occurs in the mountains of Arizona, Colorado, New Mexico, Utah, and Wyoming, U.S. It has also been reported from Elko and White Pine counties in Nevada, in Twin Falls county, Idaho, and in Montana (Cronquist et al. 1997, Kartesz 1999). In addition, it occurs in Chihuahua, Mexico (Kearney and Peebles 1960).

Over 100. Wyoming: 25+; Arizona: 20+; New Mexico: 20+; Utah: 21+; Colorado: 50+.

The Wyoming Natural Heritage Program records 25 extant occurrences and 10 historical occurrences. There may be more than that according to the Atlas of the Vascular Flora of Wyoming.

The Utah Natural Heritage Program records that it has been collected in 21 of 29 counties.

Number of populations from New Mexico is an estimate considering the number of collections (herbaria) and anecdotal reports.

There are records for 500 sites in a 5,000 square mile area collected over a 40 year period in southern Colorado (R. Hartman, personal communication). This area is the same as that from which many collections were made by Ryberg in 1906. However, it is unknown how many populations are still extant or how many plants these sites represent. Many sites may be within contiguous habitat and make up one occurrence, although each site was estimated to cover from one to four square miles.

The Arizona Natural Heritage Program reports that L. porteri is found in Apache, Coconino, Graham, Cochise counties at approximately 6,500 -11,500 feet. They report that it may also occur in Pima and Yavapai counties.

Juanita Ladyman has personally seen evidence of wild-collection in New Mexico and Arizona. In Chihuahua, Mexico, it was reported to be commonly sold in the markets (Bye 1986). Searches on the internet have revealed additional evidence of collection in New Mexico and Colorado. It is the roots that are used for medicinal purposes and so commercial harvests are very likely to be harmful to local populations.

All Ligusticum porteri is wild-collected. The plant is not in cultivation. It is very difficult to cultivate this plant and the seeds are difficult to germinate. There is broad concern about overcollection within the medicinal plant industry (e.g., http://chili.rt66.com/hrbmoore/ and http://www.frontiercoop.com/). The United Plant Savers organization has included Ligusticum porteri in their list of the 19 most threatened plants within the U.S.

Wild plant collection must be quite extensive because all Ligusticum porteri is wildcrafted and it is sold extensively over the web as well as in local herb stores. Unfortunately, companies such as "mothernature.com" do not give out information about the quantities sold. It is a best-seller at many stores in New Mexico and Arizona, especially those with customers of Spanish and Mexican origin (Chang 1998 and personal communication with herb stores). Plants collected in New Mexico may be destined for export to Mexico. In addition, material is used to manufacture pills and tinctures.

Typical collection for personal use involves filling a bushel basket (Moore 1979).

Activities associated with livestock grazing and logging are potential threats. Ligusticum porteri grows in damp areas so any land use that results in drying out such areas would be detrimental. Damp meadows are threatened habitats in many parts of the western U.S. In addition, livestock grazing itself is a potential threat to small populations as Ligusticum porteri is palatable forage (Kearney and Peebles 1960) and is a highly valued range plant in both aspen stand and weed communities in old subalpine spruce burns (U.S. Forest Service 1988).