Cupressaceae

Juniperus deppeana var. sperryi Correll

Endemic to northern Mexico and southern USA where there are very few locations which are threatened by grazing and fire

Distribution

USA, W Texas, described from two trees in the Davis Mountains and a collection made in 1931 in the Guadalupe Mountains. Zanoni & Adams (1979) cite a collection from Sonora, Mexico (T. A. Zanoni 2872, CS, n.v.) under this taxon. Other scattered trees probably exist in canyons of the semiarid mountains in the region. Adams (2011) has given a map with points in Arizona and New Mexico, as well as western Texas and one locality in NE Sonora, Mexico

Whilst more specimens are being discovered, some far distant from the original trees in Trans Pecos Texas, this variety (or form) of Juniperus deppeana remains very rare, mainly known from large, solitary trees

Habitat and Ecology

This variety is found in rocky soils on mountain slopes and in basins, usually in grassland. Found at an altitude of 1800–2000m.

Conservation Status

Global status

Critically Endangered D

Global rationale

For a long time this taxon was only known from the type, a lone tree in the Davis Mountains of Trans Pecos Texas. Later, some more trees were found in the area, but now Adams (2011) shows occurrences in Arizona, New Mexico and one locality in NE Sonora, Mexico. The number of mature trees is very limited and regeneration is almost absent. Despite the increase of known trees due to intensive surveys, it is still Critically Endangered under criterion D.

Global threats

There is an apparent lack of sufficient regeneration possibly due to fire and overgrazing.

Conservation Actions

Some trees are found within protected areas or are protected by landowners.

References and further reading

  1. Adams, R.P. (1973). Reevaluation of the biological status of Juniperus deppeana var. sperryi Correll. Brittonia 25(3): 284-289.
  2. Adams, R.P. (2011). Junipers of the World: The genus Juniperus. Trafford Publishing Co., Bloomington, Indiana.
  3. Correll, D.S. (1966). Cupressaceae. In: C.L. Lundell (ed.) Flora of Texas 1. Texas Research Foundation, Renner.
  4. Correll, D.S. (1966).  Two new plants in Texas. Wrightia 3(8): 188-191.
  5. Farjon, A. (2005). A Monograph of Cupressaceae and Sciadopitys. Royal Botanic Gardens, Kew.
  6. Farjon, A. (2013). Juniperus deppeana var. sperryi. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 06 July 2013.