Oneseed juniper provides good cover for birds and mammals including quail, wild turkey, deer, and songbirds [108]. The degree to which oneseed juniper provides environmental protection during one or more seasons for wildlife species is [28]:
CO UT pronghorn - good elk - good mule deer fair good white-tailed deer fair - small mammals good good small nongame birds good good upland game birds - good waterfowl - poor
Oneseed juniper is a native, long-lived, evergreen tree with often shrubby form, 10 to 40 feet (3-12 m) high with several curved limbs arising near the base [32,42,121,127].
Oneseed juniper produces small, "berry-like", glaucous, globular staminate cones, and subglobose ovulate cones [42,127]. Mature cones are dark blue to purple or brownish, and succulent, or at least somewhat fleshy [50,127,132]. Seeds are generally 1 per fruit, more rarely 2, reddish-brown and ovoid to globose [50,127]. Juniper seeds are described as having a semipermeable and thick seed coat with a dormant embryo [41]. The cones are often referred to as "berries" in the literature.
Mature oneseed junipers have both tap and lateral root systems. The taproots in 1 study ranged from 18 inches (46 cm) to more than 12 feet (3.7 m) in length. Of 500 trees examined, 347 had well-developed taproots. Lateral roots were widespread, commonly being 2.5 to 3 times as long as the tree was tall. Most lateral roots were in the surface 3 feet (1 m) of the soil, most of those concentrated below the surface 6 inches (15 cm) [64]. The deep root system of mature oneseed junipers is adapted for growth on dry sites [51,64,107]. Foxx and Tierney [43] reported rooting depths ranging from 16 to 197 feet (5-60 m).
Oneseed juniper is a slow-growing species. Lymbery and Pieper [80] reported an increase in height of approximately 6.3 inches (16 cm) per decade, with a corresponding increase in stem diameter of 0.5 inch (1.2 cm). Growth rate tends to vary according to site characteristics, however. On a hilly site in southwestern Texas, a oneseed juniper 35 years of age was 14 feet (4.3 m) in height with a diameter of 0.5 inch (1.3 cm) [23].
Oneseed juniper has the ability to stop active growth when moisture is limited but can resume growth when moisture availability improves [53]. This growth pattern may represent an important adaptation allowing junipers to survive on harsh, arid sites. Although small trees may be killed by drought, mature oneseed junipers are resistant to drought, especially in comparison to Colorado pinyon [64,107].Oneseed juniper is common in the desert grassland and pinyon-juniper ranges throughout New Mexico and in southeastern and north-central Arizona. This species also occurs in southern Colorado, western Texas and western Oklahoma [5,99]. Occurrence of oneseed juniper in Mexico is unclear because it is very similar morphologically to other species, especially Pinchot juniper. According to Adams [1,2], who conducted chemosystematic studies and reviewed taxonomic literature: "The one-seeded juniper group in Mexico is very complex."
The Flora of North America also provides distribution information on oneseed juniper for North America.
Oneseed juniper is susceptible to fire [87,134]. Fire mortality is generally high for both young and old trees [68], although the medium-thick bark of older trees may afford some protection [24,87,98]. A history of heavy grazing may also reduce flammability of mature oneseed juniper stands by reducing fine fuels [11,98].
In some areas, juniper is protected from fire by site factors. For example, junipers frequently grow on rocky breaks or escarpments where fire frequency is low. Wright [134] reported that nonsprouting juniper species often occupy isolated topographic breaks which may be surrounded by grasslands that are more susceptible to fire.
Fire adaptations: Postfire reestablishment is primarily through seed and is relatively slow [63]. Most establishment is from seed dispersed from off-site by birds and mammals, but some establishment may occur from seeds buried on-site and protected from the heat of fire by overlying soil layers. Establishment may be relatively poor even when good germination occurs, and growth is typically very slow [115].
Oneseed juniper is usually regarded as a nonsprouter [134], but older trees have been known to sprout infrequently after fire [24,128]. This mode of regeneration appears to be relatively unimportant, however.FIRE REGIMES: Past FIRE REGIMES in southwestern pinyon-juniper woodlands were mixed, having both surface and crown fires, and are a reflection of variable intensity and frequency depending on site productivity [48,98]. "Productive sites could sustain patchy fires at intervals of 10 to 50 years, and could have attained densities sufficient to carry crown fires at intervals of 200 to 300 years. In open stands, where grass cover was continuous, fire intervals might have been 10 years or less, and probably maintained grasslands and savannas [48]."
According to a 1962 review of oneseed juniper by Johnsen [64] (and references therein), fires were reported to have been widespread and destructive before the juniper woodlands were heavily used by settlers. A 1904 publication cited by Johnsen reported that 5% of the junipers on the Coconino National Forest had been struck and killed by lightning. Johnsen indicated that "lightning strikes are still common, but fires started in this way are usually confined to the tree struck, for only in the very dry hot periods with strong winds in the late spring will a fire carry through even a dense juniper stand".
The following table provides some fire return intervals for communities where oneseed juniper may occur. Find further 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".
Community or Ecosystem Dominant Species Fire Return Interval Range (years) desert grasslands Bouteloua eriopoda and/or Pleuraphis mutica 5-100 grama-galleta steppe Bouteloua gracilis-Pleuraphis jamesii cheatgrass Bromus tectorum 98] basin big sagebrush Artemisia tridentata var. tridentata 12-43 [111] mountain big sagebrush Artemisia tridentata var. vaseyana 15-40 [8,21,88] juniper-oak savanna Juniperus ashei-Quercus virginiana Ceniza shrub Larrea tridentata-Leucophyllum frutescens-Prosopis glandulosa pinyon-juniper Pinus-Juniperus spp. 98] Mexican pinyon Pinus cembroides 20-70 [91,123] Colorado pinyon Pinus edulis 10-49 [98] Arizona pine Pinus ponderosa var. arizonica 2-10 [7] mesquite Prosopis glandulosa mesquite-buffalo grass Prosopis glandulosa-Buchloe dactyloides oak-juniper woodland (Southwest) Quercus-Juniperus spp. 98]Historically, periodic fire is believed to have played an important role in maintaining juniper savannas [64,98,132]. Mueggler [93] reported that a fire-free period of 85 to 90 years was required for formation of a "well-developed" juniper woodland. Recent decades of fire suppression have probably contributed to encroachment of juniper into grasslands [78,94].
In some instances, forage production has increased after oneseed juniper and other species were removed by fire. On 1 "notable" Colorado pinyon-juniper site, Aro [11] reported increased forage production from 100 pounds per acre (45 kg/ha) before treatment to 500 pounds per acre (227 kg/ha) following fire. However, in other instances little long-term increase in forage production has been noted. According to Payson and others [98], most of the control operations failed to meet managers' objectives.
Individual tree burning was used on some pinyon-juniper woodlands [61,118]. Mechanical methods, such as chaining and cabling in pinyon-juniper woodlands, were often followed by the piling and burning of slash. Burning these high fuel concentrations generated high heat levels that damaged soil and site productivity. Surface soils in many of these piled areas were degraded and remained free of vegetation 20 years later [98,125].
Oneseed juniper does not survive in grasslands where fires occur frequently [134]. Broadcast burns may effectively control oneseed juniper if the species is well represented, weather conditions are favorable, and sufficient fuels are present. Dense stands (400 or more/ac (990/ha)) with a flammable understory are most suitable for broadcast burning [59,128]. In areas with a past history of heavy grazing where little fuels remain and few residual grasses occur, burning may be difficult and ineffective. Burns tend to be most successful when carried out in June when temperatures are high and humidity low [11,104]. Unfortunately, risk of escape may be great during this time period [11], and the window for burning very narrow [104].
Currently, prescribed fire in pinyon-juniper woodlands is used to reduce accumulations of slash from fuelwood harvesting or to reduce or eliminate tree cover to increase range productivity and biodiversity. Prescribed burning to dispose of slash is less desirable in partially harvested stands because residual trees are damaged and advance regeneration is killed. Established, smaller trees are particularly important for the next rotation because of the difficulty of achieving adequate regeneration of these relatively slow growing trees. Payson and others [98] provide recommendations relevant to fire management in pinyon-juniper ecosystems.
Oneseed juniper occupies xeric sites in semiarid climatic zones [38,51,102]. A typical Arizona site occupied by oneseed juniper receives 10 to 15 inches (250-380 mm) of precipitation annually, and has an average growing season of approximately 120 days [95,134]. Unlike several related species, the distribution of oneseed juniper does not appear to be limited by temperature inversions [59].
Oneseed juniper grows on dry, rocky, open flats, and slopes [32,50,52]. It commonly occurs in canyons or on middle-elevation foothills [50,134]. In many areas this juniper occurs in a zone below ponderosa pine (P. ponderosa) or alligator juniper, but above oak (Quercus spp.)-mountain-mahogany (Cercocarpus spp.) shrublands [96,134].
Because soil moisture is limited on many oneseed juniper sites, competition with others species may significantly influence the occurrence of this tree on a particular site. Grasses can compete effectively with oneseed juniper seedlings for moisture and can limit its distribution in some areas [64,135]. Many oaks also compete for soil moisture, although oneseed juniper appears to be capable of outcompeting them on shallow soils [115]. Where oneseed juniper occurs with Colorado pinyon, junipers show much more adaptation to drought stress than do the pines [107]. These observations were based on tissue water potentials and metabolic activity during the hottest part of the day.
Oneseed juniper grows on a variety of soil textures including gravelly, rocky, or sandy soils [50]. Parent materials include basalt, limestone, and sandstone [38]. Soil characteristics, combined with temperature, moisture and topography influence the upper and lower elevational extent of oneseed juniper [18,134]. Elevational ranges of oneseed juniper reported in the literature are:
Arizona 3,000 to 7,000 feet (914-2,130 m) [32,72]
Colorado 4,000 to 7,600 feet (1,220-2,315 m) [52]
New Mexico > 5,000 to 7,500 feet (1,525-2,285 m) [125]
Surface fires kill oneseed juniper trees less than 4 feet (1.2 m) tall, but have less of an impact on older, larger trees that have thicker bark and high crown base heights that exceed flame lengths [29,61,64,98]. Fast moving surface fires in the Southwest often do not burn near trunks of larger trees because the litter layer does not ignite [98].
Average mortality following a low-severity June wildfire in oak-juniper woodlands of Arizona was 76% [68]. Researchers observed 92% mortality after a stand of small, bushy oneseed juniper were burned [17]. Springfield [118] noted 70 to 100% of oneseed junipers less than 4 feet (1.2 m) in height were killed by fire. Mortality ranging from 30 to 100% has been reported in trees 5 to 6 feet (1.5-1.8 m) in height.
Researchers have found that 100% juniper mortality results when 60% of the crown is scorched [61]. Temperatures lethal to oneseed juniper tissue are also related to the degree of desiccation, and thus season of burn may also influence the amount of damage the plant sustains. Laboratory experiments have shown that temperatures lethal to oneseed juniper ranged from 140 degrees Fahrenheit to 176 degrees Fahrenheit (61.8o to 80oC). Lethal temperatures tend to be lowest during late spring and summer [58].
Pinyon-juniper woodlands provide good habitat for mule deer, bighorn sheep, bison, wild horses, pronghorns, coyotes, bobcats, badgers, porcupines, rabbits, mice, voles, woodrats, squirrels, and numerous birds [34]. The foliage and berries of oneseed juniper provide food for many species of birds and mammals.
Browse: Deer utilize the foliage of oneseed juniper [26,59,84]. Mahgoub and others [82] observed heavy utilization in parts of south-central New Mexico where juniper can represent up to 20% of the annual diet of mule deer. Oneseed juniper foliage is reported to be a major mule deer food item from January through March in parts of southeastern New Mexico [108]. Pronghorns also browse oneseed juniper, and in some areas, winter use may be heavy [20,122]. Bighorn sheep and elk may consume small amounts of juniper browse [108]. The foliage of oneseed juniper is of little value to domestic livestock. Domestic sheep and goats utilize this species to a limited extent [26,59].
Fruit: The succulent, berrylike cones of oneseed juniper serve as an abundant and readily available food source for a wide range of wildlife species. The bright cones tend to remain on the tree and can provide food year-round [34,110], but become dry and leathery by the 2nd winter [109].
It is estimated that avian population densities may be 70% greater during years with abundant juniper "berry" crops (generally every 2 to 5 years) [13]. Studies with captive birds have revealed that an average Townsend's solitaire can consume approximately 240 "berries" per day, or 36,000 to 84,000 per winter [13,110]. In some areas at least 97% of the Townsend's solitaire's winter diet may be made up of oneseed juniper "berries" [109]. Robins also consume large numbers of the berrylike cones. An individual bird can eat 220 "berries" per day or 33,000 per winter. Birds and mammals serve as important dispersal agents for seeds of oneseed juniper. Many bird species disperse seed up to 6.3 miles (10 km) or more from the seed source. Sheep and domestic cattle can also facilitate dispersal of oneseed juniper [13,64]. Salomonson [110] reported the following animals as juniper seed consumers and dispersers:
birds mammals northern flicker desert cottontail Steller's jay black-tailed jackrabbit mountain chickadee cliff chipmunk plain titmouse rock squirrel sage thrasher golden mantled ground squirrel American robin deer mouse Townsend's solitaire Mexican woodrat western bluebird coyote evening grosbeak gray fox Cassin's finch
Other wildlife species known to consume oneseed juniper berries include mule deer, western chipmunk, antelope ground squirrel, squirrels, bear, javelina, pocket mouse, rabbits, and raccoon [,64,108,119].
Common plant associates reported in the literature are:
In northern Arizona overstory associates include Utah juniper (J. osteosperma)
and Colorado pinyon (P. edulis). Associated plants include
winterfat (Krascheninnikovia lanata), skunkbush sumac (Rhus trilobata),
shrub live oak (Quercus turbinella), broom snakeweed (Gutierrezia sarothrae),
rubber rabbitbrush (Chrysothamnus nauseosus), and Russian-thistle
(Salsola kali). Associated grasses include galleta (Pleuraphis jamesii),
black grama (Bouteloua eriopoda), blue grama (B. gracilis), Fendler
threeawn (Aristida purpurea var. fendleriana), sideoats grama
(B. curtipendula), tobosa (P. mutica), and bottlebrush squirreltail
(Elymus elymoides). Other associated plants include
freckled milkvetch (Astragalus lentiginosus), cholla and prickly-pear
(Opuntia spp.), [59,74]. Occasionally oneseed juniper grows in extensive pure stands,
such as those on the Coconino Plateau in northern Arizona. It is the dominant species in
these stands and may exclude all other plants [64].
In southern Arizona oneseed juniper occurs with alligator juniper (J. deppeana),
Mexican pinyon (P. cembroides), Emory oak (Q. emoryi), Arizona white oak
(Q. arizonica), Mexican blue oak (Q. oblongifolia), and species of mesquite
(Prosopis spp.) [12,92].
In New Mexico and western Texas common associates are Colorado pinyon, Pinchot juniper,
alligator juniper,broom snakeweed, skunkbush sumac, winterfat, fourwing saltbush
(Atriplex canescens), Bigelow sagebrush (Artemisia bigelovii),
true mountain-mahogany (Cercocarpus montanus), gray oak (Q. grisea),
catclaw mimosa (Mimosa biuncifera), lechuguilla (Agave lechuguilla),
prickly-pear, sideoats grama, galleta, and blue grama [3,25,44,47,71,101,102,103].
Oneseed juniper is an indicator in a number of pinyon-juniper shrubland
and desert grassland classification systems, including:
Arizona [15,121]
Colorado [54,69]
New Mexico [3,44,71,73,121]
Texas [27,83]
Based on a study conducted near Flagstaff Arizona, annual leader elongation of oneseed juniper generally begins in April [53]. Detailed phenological development from that study is:
phenological state date bark begins to slip March 25 pollen shedding and female flowers open March 25 approximate start of leader elongation April 20 1st conspicuous formation of male flowers April 19 leader elongation ceases October 26
Flowering generally occurs in March or April [50,66], but can occur as early as January or as late as June, depending on geographic location [41]. Fruit matures in 1 season, ripening from August through November [64,66]. Seed may remain on the tree for 1 to 2 years [66]. Lymbery and Pieper [80] reported that in the northern Sacramento Mountains, flowering occurred from March to April, fruit ripening from August to September, and seed dispersal from October to November.
Regeneration of oneseed juniper is usually from seed when aboveground vegetation has been killed or seriously damaged by fire. Older oneseed junipers can occasionally sprout from the base after fire. In a southern Arizona burn, 10% of oneseed junipers resprouted. In contrast 42% of alligator juniper resprouted [68]. However, in most cases, sprouting appears to be a relatively unimportant mode of regeneration.
The length of time required for postfire recovery of oneseed juniper has not been well documented. Oneseed juniper did not become prominent after a severe wildfire in Utah until postfire year 40. This species did not regain dominance on this site until 70 years after the fire [128]. Evidence suggests that factors such as soil type and preburn community composition may significantly influence the length of time required for recovery [114]. Seedling establishment may be favored in the shade of dead vegetation, including other oneseed junipers [24]. Once established, oneseed juniper can bear seed as early as 10 years of age on some sites [114].
Breeding system: Oneseed juniper is dioecious with seed persisting on the plant for 1 to 2 years [32,64,66].
Pollination: No information
Seed production: Trees first produce seed at 10 to 30 years of age, although maximum seed production generally does not occur until 50 to 200 years of age [66,115]. Trees as short as 18 inches (46 cm) in height can produce seed [64]. Oneseed juniper typically produces large seed crops at 2- to 5-year intervals [66].
Seed dispersal: Dispersal of oneseed juniper seeds may occur through water, gravity, or by any of a number of birds and mammals [10,64]. Animal dispersal may be particularly important, as digestive processes may enhance germination [13]. Most seed cones occur on the outer edges of trees where they are most visible and accessible to birds [110]. The brightly-colored, highly-visible cones persist on the trees for much of the year, providing a continually available food source for animals [13,34]. On some sites in New Mexico, as much as 95% of juniper reproduction could be attributed to bird dispersal [30]. Domestic sheep and cattle may also aid in seed dispersal [64].
Seed banking: According to Johnsen [64], "Since the seed is not harmed by long periods of dry storage, drought probably does not affect seed viability. Viable seed in the soil may endure prolonged drought and still germinate when conditions become favorable."
Germination: See Value for Rehabilitation of Disturbed Sites for detailed information about germination experiments with this species.
Seedling establishment/growth: Seedling establishment of oneseed juniper is often very poor even when good germination occurs [114]. The growth rate has been characterized as slow with medium vigor. Researchers in some areas have found that only approximately 3% of juniper seeds develop to the seedling stage. Shade may be important for good early growth of oneseed juniper [60]. Emergence appears to be somewhat greater under trees or shrubs than in interspaces where humidity and temperature fluctuations are more extreme [64]. In some areas, small junipers are particularly numerous under the canopy of pinyon or other trees [60,115]. Most seedlings occur some distance from the parent tree, although most seeds are located beneath the source tree [110]. Seedlings seldom establish beneath mature junipers, and an autopathic effect from litter is suspected [115].
Asexual regeneration: Although oneseed juniper is usually regarded as a nonsprouter [135], limited sprouting, mostly from older trees, has been observed [24,129]. Approximately 10% of living oneseed junipers sprouted from the base following an Arizona fire [129].
Populations of oneseed juniper have been classified as climax [54,113], seral [44], late seral [27], and postclimax [64]. Schott and Pieper [113,115] examined secondary succession in pinyon-juniper several decades following cabling and concluded that re-established stands of pinyon and oneseed juniper were climax. Johnsen [64] concluded that within northern Arizona grasslands are numerous postclimax oneseed juniper stands with soil and microclimate conditions different from adjacent grasslands. The oneseed junipers maintain themselves on these areas but are not invading the surrounding grassland. Francis [44] described 4 seral phyto-edaphic community types in northwestern New Mexico where oneseed juniper is a codominant indicator species.
According to Gottfried [48] junipers are the 1st to return in secondary succession but are often followed and replaced by pinyon. "Habitat type affects the successional pathway following a disturbance. Succession on a site is influenced by the severity and size of the disturbance, and by the composition, longevity, and density of any surviving plants and propagules within the disturbed area and the characteristics of plant communities in adjacent undisturbed areas. Climatic conditions also influence the nature and speed of succession."
See Other Management Considerations for an analysis of a drought-induced ecotone shift of oneseed junipers into a declining ponderosa pine forest in Arizona.
New Mexico studies comparing plant growth in zones extending out from the boles of oneseed juniper and pinyon pine showed differences between the zones and also between the two tree species [6,112]. Grasses and other plants were consistently sparser beneath the tree canopies. The author's review of possible explanations includes allelopathy, shade, precipitation interception by the canopy, and litter cover forming a physical barrier to germinating plants. Other explanations offered to explain the reduced under-canopy vegetation include root competition for soil moisture, and possible chemical properties of oneseed juniper litter [9,62].
The currently accepted scientific name of oneseed juniper is Juniperus monosperma
(Engelm.) Sarg. (Cupressaceae) [42,70].
Reports of hybridization with Pinchot juniper (J. pinchotii) have been
refuted by use of numerous chemical and morphologic characters. The two species
have nonoverlapping pollination seasons [2,42].
Because research focused specifically on oneseed juniper is not abundant,
some information in this report is drawn from studies and reviews that pertain to
multispecies Southwestern juniper or pinyon (Pinus spp.)-juniper
(Juniperus spp.) woodlands. In this report "oneseed juniper" is used
where the study discussed focused on that species. "Juniper" or "pinyon-juniper"
describes studies broader in scope, but where oneseed juniper was usually
identified as component. When the pinyon species was identified it is included.
Oneseed juniper is rated as having low overall value for short-term rehabilitation but high value for long-term rehabilitation [28]. It was not widely used in the past for rehabilitation projects because of unreliable seed germination. Fertilizers, wood chips, straw mulch, plastic mesh protection against rodents, and drip irrigation can all contribute to increased survival on disturbed sites. Oneseed juniper has been successfully planted on surface coal and uranium mines in the Southwest. Improved techniques have resulted in survival rates as high as 99% [40,41].
In a New Mexico study of planted seed, drip irrigation was more effective than mulch, while triple-superphosphate aided growth more than slow-release fertilizers. On these sites, July planting dates produced best results at higher elevations, whereas August plantings were most successful on low elevation sites [40].
Transplanting containerized seedlings onto disturbed sites has also been a successful technique [39,40,41]. In New Mexico, survival is best when trees are planted after the June drought but before the ground freezes. Survival of transplants is heavily dependent on moisture availability. Mulch aids in water conservation and can enhance survival on dry sites. Drip irrigation may be necessary on the most arid sites. Researchers suggested that fertilizer may improve survival on some sites particularly when combined with irrigation [40,41]. In another New Mexico study of rehabilitation of surface-mined land, survival of transplanted containerized seedlings was improved by wood chip mulch and animal protection using rigid mesh. In this study, fertilizer provided no benefit and decreased oneseed juniper survival where seeded grasses were able to outcompete. Competition from weeds also reduced juniper growth and survival [39].
Germinating juniper seeds is difficult. Seeds may require a period of afterripening [41]. Pack [97] found that high temperatures, alternating temperatures, freezing and thawing, removal of the seed coat, application of hydrogen peroxide, dilute acids, carbon dioxide, or light had little influence on germination of juniper seeds. Cold stratification may improve germination in oneseed juniper [66]. Fischer and others [41] found that germination improved when seeds were leached 48 hours with hydrogen peroxide, or treated with ethephon or hydrogen peroxide plus gibberellic acid followed by cold stratification .
Experiments suggest that exposure to sunlight may have relatively little effect on germination. Johnsen [64] observed average germination of 44% for seeds grown in the dark, and 52% for seeds exposed to sunlight. Soil moisture may be an important factor influencing germination. Germination appears to be best in moist but not saturated soil. Seeds of oneseed juniper do not germinate well on the soil surface which is subject to rapid desiccation. Juniper seeds appear to be resistant to drought when buried in the soil [63,64]. Buried seeds can often retain viability and germinate when moisture conditions become favorable. Approximately 54% of oneseed juniper seed stored for 21 years germinated [63].
Juniperus monosperma is a species of juniper native to western North America, in the United States in Arizona, New Mexico, southern Colorado, western Oklahoma (Panhandle), and western Texas, and in Mexico in the extreme north of Chihuahua. It grows at 970–2300 m altitude.[2][3]
It is an evergreen coniferous shrub or small tree growing to 2–7 metres (6+1⁄2–23 feet) (rarely to 12 m) tall, usually multistemmed, and with a dense, rounded crown. The bark is gray-brown, exfoliating in thin longitudinal strips, exposing bright orange brown underneath. The ultimate shoots are 1.2–1.9 millimetres thick. The leaves are scale-like, 1–2 mm long and 0.6–1.5 mm broad on small shoots, up to 10 mm long on vigorous shoots; they are arranged in alternating whorls of three or opposite pairs. The juvenile leaves, produced on young seedlings only, are needle-like. The cones are berry-like, with soft resinous flesh, subglobose to ovoid, 5–7 mm long, dark blue with a pale blue-white waxy bloom, and contain a single seed (rarely two or three); they mature in about 6–8 months from pollination, and are eaten by birds and mammals.[4] The male cones are 2–4 mm long, and shed their pollen in late winter. It is usually dioecious, with male and female cones on separate plants, but occasional monoecious plants can be found.[2][3] Its roots have been found to extend to as far as 61m below the surface, making it the plant with the second deepest roots, after Boscia albitrunca.[5]
Frequently, cones can be found with the seed apex exposed; these were formerly sometimes considered a separate species as Juniperus gymnocarpa, but this is now known to be due to insect damage to the developing cones (and can affect many different species of juniper); the seeds from such cones are sterile.[3]
It is very rare or even extinct in Mexico, with only a single herbarium collection from 1880 verified;[2] more recent searches have failed to find the species there.[3] A closely related species Juniperus angosturana was however formerly considered a variety, as J. monosperma var. gracilis Martínez; it differs from J. monosperma in its slenderer shoots 1.0–1.3 mm diameter.[2][3]
Other vernacular names occasionally used include single-seed juniper and cherrystone juniper.
Hopi chipmunks, quail, foxes, rock squirrels and deer eat the berrylike cones. New Mexico's goats browse the foliage.[6]
Historically, the Navajo ate the ripened cones in the fall or winter and made a dye from the bark and cones. They used its wood for various purposes.[6] Among the Zuni people, a poultice of the chewed root was applied to increase the strength of newborns and infants. An infusion of the leaves was also taken for muscle aches and to prevent conception. An infusion of the leaves was also taken postpartum to prevent uterine cramps and stop vaginal bleeding.[7] A simple or compound infusion of twigs was used to promote muscular contractions at birth and used after birth to stop blood flow.[8] The wood was also used as a favorite and ceremonial firewood, and the shredded, fibrous bark was specifically used as tinder to ignite the fire sticks used for the New Year fire.[9]
Juniperus monosperma is a species of juniper native to western North America, in the United States in Arizona, New Mexico, southern Colorado, western Oklahoma (Panhandle), and western Texas, and in Mexico in the extreme north of Chihuahua. It grows at 970–2300 m altitude.
It is an evergreen coniferous shrub or small tree growing to 2–7 metres (6+1⁄2–23 feet) (rarely to 12 m) tall, usually multistemmed, and with a dense, rounded crown. The bark is gray-brown, exfoliating in thin longitudinal strips, exposing bright orange brown underneath. The ultimate shoots are 1.2–1.9 millimetres thick. The leaves are scale-like, 1–2 mm long and 0.6–1.5 mm broad on small shoots, up to 10 mm long on vigorous shoots; they are arranged in alternating whorls of three or opposite pairs. The juvenile leaves, produced on young seedlings only, are needle-like. The cones are berry-like, with soft resinous flesh, subglobose to ovoid, 5–7 mm long, dark blue with a pale blue-white waxy bloom, and contain a single seed (rarely two or three); they mature in about 6–8 months from pollination, and are eaten by birds and mammals. The male cones are 2–4 mm long, and shed their pollen in late winter. It is usually dioecious, with male and female cones on separate plants, but occasional monoecious plants can be found. Its roots have been found to extend to as far as 61m below the surface, making it the plant with the second deepest roots, after Boscia albitrunca.
Frequently, cones can be found with the seed apex exposed; these were formerly sometimes considered a separate species as Juniperus gymnocarpa, but this is now known to be due to insect damage to the developing cones (and can affect many different species of juniper); the seeds from such cones are sterile.
It is very rare or even extinct in Mexico, with only a single herbarium collection from 1880 verified; more recent searches have failed to find the species there. A closely related species Juniperus angosturana was however formerly considered a variety, as J. monosperma var. gracilis Martínez; it differs from J. monosperma in its slenderer shoots 1.0–1.3 mm diameter.
Other vernacular names occasionally used include single-seed juniper and cherrystone juniper.
