Juniperus ashei

Juniperus ashei (Ashe juniper, mountain cedar, blueberry juniper, post cedar, or just cedar) is a drought-tolerant evergreen tree, native from northeastern Mexico and the south-central United States to southern Missouri. The largest areas are in central Texas, where extensive stands occur. Ashe juniper grows up to 10 metres (33 feet) tall, and over time can reach 15 m (49 ft), and provides erosion control and year-round shade for wildlife and livestock.

Juniperus ashei
J. ashei shedding pollen: mature male on right, immature tree on left, mature green females in background
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnosperms
Division: Pinophyta
Class: Pinopsida
Order: Cupressales
Family: Cupressaceae
Genus: Juniperus
Species:
J. ashei
Binomial name
Juniperus ashei
J. Buchholz
Natural range of Juniperus ashei
Synonyms

J. sabinoides (H.B.K.) Nees sensu Sargent
J. mexicana Spreng
J. monticola Martinez
Sabina sabinoides (H.B.K.) Small [2]

Description

The feathery foliage grows in dense sprays, bright green in color. The leaves are scale-like, 2 to 5 millimetres (1⁄16 to 3⁄16 inch) long, and produced on rounded (not flattened) shoots. It is a dioecious species, with separate male and female plants. The seed cones are round, 3 to 5 mm (1⁄8 to 3⁄16 in) long, and soft, pulpy and berry-like, green at first, maturing purple about 8 months after pollination. They contain one or two seeds, which are dispersed when birds eat the cones and pass the seeds in their droppings. The male cones are 3–5 mm long, yellow, turning brown after pollen release in December to February.

Scientific name

The specific name ashei pays homage to American forester and botanist William Willard Ashe.[3]

As an invasive species

Despite being native to Texas, ashe juniper is often considered an invasive species and weed by many landowners and ranchers. It is commonly believed that they use more water than live oaks, but more recent research suggests the reverse.[4][5][6][7][8]

Ashe juniper thrives on ranches, as cattle avoid the bitter-tasting seedlings. In contrast to the redberry juniper, ashe juniper does not resprout when cut.[9]

Allergens

Ashe juniper pollen, along with that of the related Juniperus virginiana, can cause a severe allergic reaction. Consequently, what begins as a winter allergy may extend into spring, as the pollination of J. virginiana follows that of J. ashei. Colloquially, many Texans refer to the allergy as cedar fever.

Uses

Spanish explorers who arrived in what is now Texas in the mid-18th century built Hill Country missions using ashe junipers for roof beams. Poor land management, due to decades of clearcutting and overgrazing, led to soil erosion and a preponderance of caliche. The ashe juniper was one of the few plants that could thrive in the rocky soil.

The wood is naturally rot-resistant and provides raw material for fence posts. Posts cut from old-growth Ashe junipers have been known to last in the ground for more than 50 years. Over 100 years ago, most old-growth Ashe junipers were cut and used not only for fence posts, but also for foundation piers, telegraph and telephone poles, roof framing, and railroad ties.[10][11][12][13]

The berry-like cones are eaten by a number of wildlife.[14][15] The endangered golden-cheeked warbler uses the shredding bark of older Mountain Cedars to build its nests and old-growth cedar brakes and juniper-oak woodlands as habitat.

References
  1. Farjon, A. (2020). "Juniperus ashei". IUCN Red List of Threatened Species. 2020: e.T42224A179047527. doi:10.2305/IUCN.UK.2020-3.RLTS.T42224A179047527.en. Retrieved 13 November 2021.
  2. United States Forest Service
  3. Coker, W. C.; Holmes, J. S.; Korstian, C. F. (1932). "WILLIAM WILLARD ASHE". Journal of the Elisha Mitchell Scientific Society. 48 (1): 40–47. ISSN 0013-6220.
  4. Fannin, Blair, 2008. “Research Could Change Perception of Woody Species Use of Water in Edwards Plateau,” AgriLife Today online. July 30.
  5. Hauwert, Nico M. and Jack M. Sharp, 2014. “Measuring Autogenic Recharge over a Karst Aquifer Utilizing Eddy Covariance Evapotranspiration,” Journal of Water Resource and Protection. Volume 6:869-879.
  6. Gregory, Lucas Frank, 2006. Water Budgets and Cave Recharge on Juniper Rangelands in the Edwards Plateau. Texas A&M University Thesis.
  7. Owens, Keith M., Robert K. Lyons, and Chris L. Alejandro. 2006. “Rainfall Partitioning within Semiarid Juniper Communities: Effects of Event Size and Canopy Cover,” Hydrological Processes. Volume 20: 3179-3189.
  8. Schwinning, Susanne, 2008. “The Water Relations of Two Evergreen Tree Species in a Karst Savanna,” Oecologia. Volume 158: 373-383.
  9. McGinty, Allan (18 March 1997). "JUNIPER ECOLOGY". unidentified. Archived from the original on 16 April 2009. Retrieved 2009-01-10.
  10. Bray, William L., 1904. Forest Resources of Texas, U.S. Department of Agriculture, Bureau of Forestry, Bulletin No. 47. Government Printing Office: Washington D.C.
  11. Roemer, Dr. Ferdinand, 1983. Roemer’s Texas 1845 to 1847. German-Texas Heritage Society. Eakin Press: Austin.
  12. Brown, Frank, 1875. Annals of Travis County and of the City of Austin: From the Earliest Time to the Close of 1875, Vol. 6. Austin History Center.
  13. Austin Daily Democratic Statesman, September 10, 1874.
  14. Little, Elbert L. (1980). The Audubon Society Field Guide to North American Trees: Eastern Region. New York: Knopf. p. 307. ISBN 0-394-50760-6.
  15. Chavez-Ramirez, Felipe, 1992. The Role of Birds and Mammals in the Dispersal Ecology of Ashe Juniper in the Edwards Plateau. Texas, A&M University Thesis.

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