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SPECIES:  Garrya wrightii
Wright's silktassel in fruit. Image by Russ Kleinman, Pinos Altos Range, used with permission of the Western New Mexico University Department of Natural Sciences and the Dale A. Zimmerman Herbarium.



SPECIES: Garrya wrightii
AUTHORSHIP AND CITATION: Uchytil, Ronald J. 1990. Garrya wrightii. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: [].
ABBREVIATION: GARWRI SYNONYMS: NO-ENTRY NRCS PLANT CODE: GAWR3 COMMON NAMES: Wright's silktassel Wright silktassel silktassel quinine-bush coffeberry-bush coffee berry bearberry feverbush grayleaf dogwood TAXONOMY: The currently accepted scientific name of Wright's silktassel is Garrya wrightii Torr. (Garryaceae) [12,13]. LIFE FORM: Shrub FEDERAL LEGAL STATUS: No special status OTHER STATUS: NO-ENTRY


SPECIES: Garrya wrightii
GENERAL DISTRIBUTION: Wright's silktassel occurs in southern and central Arizona, southern New Mexico, the Trans-Pecos region of Texas, and northern Mexico [13].
Distribution of Wright's silktassel. Map courtesy of USDA, NRCS. 2018. The PLANTS Database. National Plant Data Team, Greensboro, NC [2018, July 11] [36].
   FRES21  Ponderosa pine
   FRES34  Chaparral - mountain shrub
   FRES35  Pinyon - juniper
   FRES40  Desert grasslands


    7  Lower Basin and Range
   12  Colorado Plateau
   13  Rocky Mountain Piedmont

   K019  Arizona pine forest
   K023  Juniper - pinyon woodland
   K031  Oak - juniper woodlands
   K032  Transition between K031 and K037
   K058  Grama - tobosa shrubsteppe

   237  Interior ponderosa pine
   239  Pinyon - juniper
   240  Arizona cypress
   241  Western live oak

504 Juniper-pinyon pine
733 Juniper-oak
735 Sideoats grama-sumac-juniper

Wright's silktassel occurs as scattered individuals in many different
plant communities.  It rarely occurs as a dominant.  It is most abundant
in interior chaparral dominated by evergreen oaks (Quercus turbinella,
Q. grisea) and birchleaf mountain-mahogany (Cercocarpus betuloides) or
true mountain-mahogany (C.  montanus) and as an understory component of
pinyon-juniper woodlands [3,7,20].  Published classification schemes
listing Wright's silktassel as a indicator species or dominant part of the
vegetation are listed below:

Vegetation of the Organ Mountains, New Mexico [7]


SPECIES: Garrya wrightii
IMPORTANCE TO LIVESTOCK AND WILDLIFE: Livestock: In Arizona chaparral, livestock prefer Wright's silktassel over many other shrub species [34], and it is reportedly good browse for cattle in the Trans-Pecos region of Texas [27]. In many areas, however, it is considered worthless for livestock forage [5,11]. Goats readily eat Wright's silktassel [5,14]. Wildlife: Wright's silktassel provides a stable supply of browse for deer and elk in chaparral and pinyon-juniper communities. Desert bighorn sheep browse this shrub [16]. Seasonal consumption of Wright's silktassel by mule deer and elk in a pinyon-juniper woodland in southwestern New Mexico is summarized below [32]: Percent composition of the diet (leaves and stems) Winter Spring Summer Autumn mule deer 3 4 4 5 elk 3 9 12 14 Following prescribed burning in central Arizona chaparral, white-tailed deer browsed 8 percent of Wright's silktassel sprouts from May through July, and 14 percent in September [29]. Another study in central Arizona chaparral found that deer and cattle use of Wright's silktassel sprouts following prescribed burning was high. This use is summarized below [24]: deer use only, second growing deer and cattle use, third season following fire growing season following fire 51 percent utilization 25 percent utilization PALATABILITY: Wright's silktassel contains quininelike substances which produce a bitter taste and may account for its relatively low palatability to cattle [35]. It is highly palatable to goats [14]. White-tailed deer and mule deer "relative preference" for Wright's silktassel is as follows [31]: Winter Spring Summer Autumn mule deer low low low low white-tailed deer high medium low medium NUTRITIONAL VALUE: Wright's silktassel browse is readily digestible. Throughout the year, however, it is low in protein and phosphorus and has a low phosphorus/calcium ratio. It is lower in protein than many associated shrubs. Seasonal nutrient composition and in vitro digestibility of current annual twig growth from plants in a southwestern New Mexico pinyon-juniper woodland was reported as follows [32]: (% of dry weight) ----------------------------------- Digestibility Protein Phosphorus P:Ca ratio Winter 55 5.2 0.12 0.11 Spring 58 6.1 0.13 0.05 Summer 56 6.9 0.13 0.15 Autumn 53 5.6 0.09 0.06 Following burning, crude protein levels of sprouts is much higher than that of unburned plants. Crude protein of sprouts, recorded during the first growing season following a September prescribed burn in Arizona chaparral, is presented below [29]: Date Crude Protein (% of dry weight) May 1 14 June 1 13 July 1 7 August 1 8 September 1 10 Oct-March 5-7 COVER VALUE: Wright's silktassel presumably provides cover for wild and domestic animals. VALUE FOR REHABILITATION OF DISTURBED SITES: Silktassels (Garrya spp.) are sometimes used for erosion control. Fruit collection, seed storage, seed treatment, and sowing methods have been detailed [30]. Nursery-grown seedlings are ready for transplanting at 2 years of age [30]. OTHER USES AND VALUES: Wright's silktassel is used as an ornamental [33]. Rubber has been made from this plant in small quantities [13]. OTHER MANAGEMENT CONSIDERATIONS: Wright's silktassel is moderately resistant to phenoxy herbicides. Following spraying, leaves and stems may die, but most plants eventually refoliate or sprout from the root crown [10]. Plants are susceptible to root plowing [3,10]. Recommendations for chemical and mechanical control of Arizona chaparral shrubs have been discussed [10].


SPECIES: Garrya wrightii
GENERAL BOTANICAL CHARACTERISTICS: Wright's silktassel is a 3- to 10-foot (1-3 m) tall evergreen shrub with stout, quadrangular branches and thick, leathery, light green leaves [13,37]. Plants are dioecious, and the flowers of both sexes occur in loose or dense catkinlike spikes [13]. The purple berries are 0.17 to 0.33 inch (4-8 mm) in diameter and contain one or two brown seeds [37]. RAUNKIAER LIFE FORM: Phanerophyte REGENERATION PROCESSES: Wright's silktassel reproduces sexually through abundant seed. The seeds are encased within a small globose to ovoid berry. Seeds are probably dispersed by birds which feed on the berries. Some seeds exhibit embryo dormancy; others germinate without any pretreatment [30]. Under laboratory conditions, germination of pretreated seeds varied from 47 to 86 percent [30]. Seedbanking: Following prescribed burning in Arizona chaparral, Wright's silktassel seedlings emerged during 4 out of 5 years following the fire, indicating that viable seeds were stored in the soil [23]. Sprouting: Following damage to the aboveground portion of the plant, most plants regenerate by sprouting from the root crown [10]. SITE CHARACTERISTICS: Wright's silktassel is primarily found in interior chaparral and as an understory component in pinyon-juniper, and open oak and pine-oak woodlands [5,6,18,20,21]. Wright's silktassel is common on both north and south exposures throughout Arizona chaparral and is most abundant from 5,000 to 8,000 feet (1,524-2,438 m) in elevation [3]. Associated shrubs in Arizona chaparral include turbinella oak, Emory oak (Quercus emoryi), true mountain-mahogany, birchleaf mountain-mahogany, skunkbush sumac (Rhus trilobata), desert ceanothus (Ceanothus greggii), pointleaf manzanita (Arctostaphylos pungens), Pringle manzanita (A. pringlei), yellowleaf silktassel (Garrya flavescens), and hollyleaf buckthorn (Rhamnus crocea) [3,10,21]. Shrub associates in semidesert grasslands, pinyon-juniper woodlands, and oak woodlands are commonly the same shrubs with which Wright's silktassel is associated in nearby chaparral communities [7,19]. In southern New Mexico and western Texas, Wright's silktassel is common in oak scrub communities dominated by gray oak (Quercus grisea), coahuila scrub oak (Q. intricata), and hairy mountain-mahogany (Cercocarpus montanus var. paucidentatus) [6,7]. Elevational ranges are presented below [1,13,27]: from 4,000 to 5,500 feet (1,219-1,676 m) in Trans-Pecos TX 3,000 to 8,000 feet (914-2,438 m) in AZ 4,300 to 7,200 feet (1,311-2,195 m) in the Rincon Mtns. AZ SUCCESSIONAL STATUS: Wright's silktassel is a common component of interior chaparral, a vegetation type considered to be a true climactic climax susceptible to large-scale burning [3]. The sprouting capability of Wright's silktassel allows it to become a part of the immediate postfire community. Individual plants may live to be very old, although the aboveground portion may extend back only to the last fire [21]. SEASONAL DEVELOPMENT: Wright's silktassel flowers from March to August in Arizona and from May to August in Texas [27,30]. Fruits ripen from August to September in Arizona [27].


SPECIES: Garrya wrightii
FIRE ECOLOGY OR ADAPTATIONS: Wright's silktassel sprouts from the root crown following top-kill by fire [10,22]. Severe wildfires are common in Arizona chaparral as a result of heavy fuel accumulation and low early summer rainfall [22]. Fire frequencies are generally between 20 to 80 or 100 years, although some stands may be older [3]. Most chaparral species are well adapted to fire and recover quickly. It takes at least 20 years before enough fuel accumulates to support a repeat burn, unless the area was seeded with grasses [3]. FIRE REGIMES: Find fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes". POSTFIRE REGENERATION STRATEGY: Tall shrub, adventitious-bud root crown


SPECIES: Garrya wrightii
IMMEDIATE FIRE EFFECT ON PLANT: Fire generally top-kills Wright's silktassel. Wildfires in Arizona chaparral are often severe, defoliating all aboveground vegetation and leaving only charred stems and a layer of ash over mineral soil [2,22]. Prescribed burning in September in Arizona chaparral 6 weeks following shrub desiccation with herbicides resulted in 88.5 to 99.0 percent shrub top-kill. Ninety five percent of Wright's silktassel shrubs were top-killed in these fall burns [23]. DISCUSSION AND QUALIFICATION OF FIRE EFFECT: Wright's silktassel is susceptible to repeated burning. Sprouts initiated after fire can be completely eliminated or significantly reduced if burned again within 1 to 3 years. Pond and Cable [25] reported that four annual burns or two burns spaced 2 years apart killed Wright's silktassel. Burning at 3-year intervals significantly reduced the number of sprouts. PLANT RESPONSE TO FIRE: Following top-kill by fire, most Wright's silktassel plants sprout vigorously from the root crown [3,23]. Plant recovery: In turbinella oak-mountain-mahogany chaparral in central Arizona, recovery of Wright's silktassel following prescribed burning in September, 6 weeks after brush was desiccated with a phenoxy herbicide, was as follows [23]: percent crown cover Post fire year pretreatment post treatment 1 2 3 4 5 6.9 0.3 0.8 1.1 0.8 0.8 1.0 Browsing by deer may have accounted for Wright's silktassel's slow recovery in this study. Seedbanking: Following the fire described above, Wright's silktassel seedlings emerged in late summer. Seedling emergence and seedling survival is summarized below [23]: number of seedlings per acre Post fire year 1 2 3 4 5 seedlings emerging 102 86 16 0 9 *seedlings surviving at end of growing season 93 121 32 73 45 * For seedling survival, columns 1 and 2 were based on four annual burns; columns 3, 4, and 5 were based on three, two, and one annual burn, respectively. Seedling survival data are therefore not additive of seedling emergence data. DISCUSSION AND QUALIFICATION OF PLANT RESPONSE: NO-ENTRY FIRE MANAGEMENT CONSIDERATIONS: Arizona chaparral often has high fuel loads (up to 40 tons/acre [89,611 kg/ha] in long-unburned stands) which can result in extreme burning conditions during late spring and early summer [22]. In general, fall is the best time for prescribed burning in this vegetation type [3]. Desiccation of brush with phenoxy herbicides or partial crushing allows for prescribed burning during periods of relatively low hazard [3,22]. Repeat burning, which is sometimes desirable for suppressing or killing shrub sprouts, is usually difficult or impossible in Arizona chaparral because it takes several years to produce enough fuel to carry a fire [10].


SPECIES: Garrya wrightii
REFERENCES: 1. Bowers, Janice E.; McLaughlin, Steven P. 1987. Flora and vegetation of the Rincon Mountains, Pima County, Arizona. Desert Plants. 8(2): 50-94. [495] 2. Cable, Dwight R. 1957. Recovery of chaparral following burning and seeding in central Arizona. Res. Note. No. 28. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 6 p. [6342] 3. Cable, Dwight R. 1975. Range management in the chaparral type and its ecological basis: the status of our knowledge. Res. Pap. RM-155. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 30 p. [579] 4. Carmichael, R. S.; Knipe, O. D.; Pase, C. P.; Brady, W. W. 1978. Arizona chaparral: plant associations and ecology. Res. Pap. RM-202. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 16 p. [3038] 5. Dayton, William A. 1931. Important western browse plants. Misc. Publ. 101. Washington, DC: U.S. Department of Agriculture. 214 p. [768] 6. Dick-Peddie, William A.; Alberico, Michael S. 1977. Fire ecology study of the Chisos Mountains, Big Bend National Park, Texas: Phase I. CDRI Contribution No. 35. Alpine, TX: The Chihuahuan Desert Research Institute. 47 p. [5002] 7. Dick-Peddie, W. A.; Moir, W. H. 1970. Vegetation of the Organ Mountains, New Mexico. Science Series No. 4. Fort Collins, CO: Colorado State University, Range Science Department. 28 p. [6699] 8. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 9. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998] 10. Hibbert, Alden R.; Davis, Edwin A.; Scholl, David G. 1974. Chaparral conversion potential in Arizona: Part I: water yield response and effects on other resources. Res. Pap. RM-126. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 36 p. [1144] 11. Judd, B. Ira. 1962. Principal forage plants of southwestern ranges. Stn. Pap. No. 69. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 93 p. [1302] 12. Kartesz, John T.; Kartesz, Rosemarie. 1980. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume II: The biota of North America. Chapel Hill, NC: The University of North Carolina Press; in confederation with Anne H. Lindsey and C. Richie Bell, North Carolina Botanical Garden. 500 p. [6954] 13. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock, Elizabeth. 1960. Arizona flora. 2d ed. Berkeley, CA: University of California Press. 1085 p. [6563] 14. Knipe, O. D. 1982. Angora goats for conversion of Arizona chaparral: early results. In: Conrad, C. Eugene; Oechel, Walter C., technical coordinators. Proceedings of the symposium on dynamics and management of Mediterranean-type ecosystems; 1981 June 22-26; San Diego, CA. Gen. Tech. Rep. PSW-58. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 264-269. [6028] 15. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384] 16. Lamb, S. H. 1971. Woody plants of New Mexico and their value to wildlife. Bull. 14. Albuquerque, NM: New Mexico Department of Game and Fish. 80 p. [9818] 17. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession following large northern Rocky Mountain wildfires. In: Proceedings, Tall Timbers fire ecology conference and Intermountain Fire Research Council fire and land management symposium; 1974 October 8-10; Missoula, MT. No. 14. Tallahassee, FL: Tall Timbers Research Station: 355-373. [1496] 18. Medina, Alvin L. 1987. Woodland communities and soils of Fort Bayard, southwestern New Mexico. Journal of the Arizona-Nevada Academy of Science. 21: 99-112. [3978] 19. Minckley, W. L.; Clark, Thomas O. 1981. Vegetation of the Gila River Resource Area, eastern Arizona. Desert Plants. 3(3): 124-140. [10863] 20. Niering, William A.; Lowe, Charles H. 1984. Vegetation of the Santa Catalina Mountains: community types and dynamics. Vegetatio. 58: 3-28. [12037] 21. Pase, Charles P.; Brown, David E. 1982. Interior chaparral. In: Brown, David E., ed. Biotic communities of the American Southwest--United States and Mexico. Desert Plants. 4(1-4): 95-99. [1826] 22. Pase, Charles P.; Granfelt, Carl Eric, tech. coords. 1977. The use of fire on Arizona rangelands. Arizona Interagency Range Committee Publication No. 4. [Place of publication unknown]: [Arizona Interagency Range Committe]. 15 p. [1827] 23. Pase, Charles P.; Lindenmuth, A. W., Jr. 1971. Effects of prescribed fire on vegetation and sediment in oak-mountain mahogany chaparral. Journal of Forestry. 69: 800-805. [1829] 24. Pase, Charles P.; Pond, Floyd W. 1964. Vegetation changes following the Mingus Mountain burn. Res. Note RM-18. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 8 p. [5700] 25. Pond, Floyd W.; Cable, Dwight R. 1960. Effect of heat treatment on sprout production of some shrubs of the chaparral in central Arizona. Journal of Range Management. 13: 313-317. [260] 26. Pond, Floyd W.; Cable, Dwight R. 1962. Recovery of vegetation following wildfire on a chaparral area in Arizona. Research Note RM-72. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 4 p. [12059] 27. Powell, A. Michael. 1988. Trees & shrubs of Trans-Pecos Texas including Big Bend and Guadalupe Mountains National Parks. Big Bend National Park, TX: Big Bend Natural History Association. 536 p. [6130] 28. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843] 29. Reynolds, Hudson G. 1967. Chemical constituents and deer use of some crown sprouts in Arizona chaparral. Journal of Forestry. 65(12): 905-908. [12057] 30. Reynolds, Hudson G.; Alexander, Robert R. 1974. Garrya Dougl. silktassel. In: Schopmeyer, C. S., ed. Seeds of woody plants in the United States. Agriculture Handbook No. 450. Washington, DC: U.S. Department of Agriculture, Forest Service: 420-421. [7670] 31. Severson, Kieth E.; Medina, Alvin L. 1983. Deer and elk habitat management in the Southwest. Journal of Range Management Monograph No. 2. Denver: Society for Range Management. 64 p. [2110] 32. Short, Henry L.; Evans, Wain; Boeker, Erwin L. 1977. The use of natural and modified pinyon pine-juniper woodlands by deer and elk. Journal of Wildlife Management. 41(3): 543-559. [12036] 33. Steger, Robert E.; Beck, Reldon F. 1973. Range plants as ornamentals. Journal of Range Management. 26: 72-74. [12038] 34. Swank, Wendell G. 1958. The mule deer in Arizona chaparral. Wildlife Bulletin No. 3. Phoenix, AZ: State of Arizona, Game and Fish Department. 109 p. [12327] 35. U.S. Department of Agriculture, Forest Service. 1937. Range plant handbook. Washington, DC. 532 p. [2387] 36. U.S. Department of Agriculture, Natural Resources Conservation Service. 2018. PLANTS Database, [Online]. U.S. Department of Agriculture, Natural Resources Conservation Service (Producer). Available: [34262] 37. Vines, Robert A. 1960. Trees, shrubs, and woody vines of the Southwest. Austin, TX: University of Texas Press. 1104 p. [7707]

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