A study of postfire recovery in a southwestern Montana rangeland by Nimir and Payne [98] found limited evidence that fire reduces old man's whiskers immediately after burning. Although specific fire dates were not provided, it may be inferred that prescribed burning was conducted sometime in late May or early June on 2 sites. The burns were described as incomplete, "leaving some areas completely unburned, some partially burned, and others completely burned." Site 1 had "the most complete burn," perhaps due to its greater exposure to sun and wind and earlier snowmelt, compared with site 2 where "the fire was much less intense." Weekly estimates of old man's whiskers cover were averaged over a 12-week period following burning. On site 1, average cover was 1.70 sq dm2 / 20 sq dm on the unburned plots and 0.90 dm2 /20 dm2 on the burned plots. On site 2, average cover was 0.29 dm2/20 dm2 on the unburned plots and 0.20 dm2 /20 dm2 on the burned plots. The average cover values on site 1 were described as significantly (p< 0.01) different, while no difference in old man's whiskers cover between burned and unburned plots was detected for site 2. Old man's whiskers productivity, as measured in clipped plots, was described as significantly (no p-value provided) different between burned (32 kg/ha) and unburned (294 kg/ha) plots at site 1, while no information on old man's whiskers productivity at site 2 was provided. Statistical methods were not described for this study. Based on the above information it was concluded that old man's whiskers was "reduced by burning at both sites," and old man's whiskers was included in a list of species "damaged" by fire [98].
Schwecke and Hann [110] described a monitoring program that tracked the effects of prescribed burning on vegetation in a Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca)/rough fescue habitat type in western Montana. Their postfire observations suggest no negative effect of fire. Within sampling plots, individual plants (quantity not provided) were marked for monitoring prior to burning. Following both spring and fall burning, there was 0% mortality among the old man's whiskers plants that were monitored. Burn conditions were described (see [110]). The publication provides no qualitative description of direct fire effects on individual plants and no explanation for the lack of fire-caused mortality.
Several studies indicate that old man's whiskers populations may increase following fire.
Bailey and Anderson [14] reported that old man's whiskers was among several perennial forbs
that "responded quickly" following prescribed burning in rough fescue-porcupine
grass (Hesperostipa spartea) grasslands in central Alberta, but no data or further
description were provided. Bork and others [27] reported that old man's whiskers increased
"prominently" following prescribed burning in shrub-encroached grassland in
northwestern Alberta, but again, no data or further description were provided.
Bork and others [26] examined vegetation response following a December wildfire that
burned in rough fescue-Parry oatgrass (Danthonia parryi) grassland in southwestern
Alberta. No preburn data were collected. Estimated June mean canopy cover of old man's whiskers
in the interior of the burned area was 1.6% and 2.2% in postfire years 1 and 2, respectively.
Similar estimates were 0.1% and 0.3% along the perimeter of the burned area, and adjacent
unburned plots contained no old man's whiskers. Estimated mean 1- and 2-year postfire litter cover
was 11.2% and 55.4% in the interior of the burned area, 39.6% and 76.3% along the perimeter
of the burned area, and 91.7% and 97.9% in the adjacent unburned plots [26]. Although not
discussed by the authors, old man's whiskers cover following the fire may have been related to
litter consumption.
These data strongly suggest that old man's whiskers presence was diminished by both fire treatments.
Another study demonstrated no net effect of fire on old man's whiskers populations. Menke and Muir [92]
studied the effects of fire on a grassland community in the Snake River Canyon, southwestern Idaho.
Mean prefire cover and 1- and 2-year postfire cover of old man's whiskers were not significantly (p<0.05)
different within either the burned or unburned plots, and there was no significant difference (p = 0.70)
in magnitude and direction of year-to-year changes between burned and unburned areas [92].
The following Research Project Summary provides information on prescribed fire use and postfire response of many
plant species, including old man's whiskers:
Understory recovery after low- and high-intensity fires in northern Idaho
ponderosa pine forests
This description provides characteristics that may be relevant to fire ecology, and is not meant for identification. Keys for identification are available (e.g. [25,36,50,51,54,58,60,61,69,73,87,95, 123,126]).
Old man's whiskers is a perennial forb [25,36,50,51,54,58,61,62,70,73,82,87, 126] with erect or ascending stems [60,73,82] 5.9 to 20 inches (15-50 cm) tall [25,36,50,54,58,60,61,73,82,87], often forming clumps 8 to 16 inches (20-40 cm) or more wide [54,61].
Leaves are generally basal [58,60,61], 0.8 to 7.9 inches (2-20 cm) long [25,36,50,54,58,60,61,73,82,126], these being numerous [73] and unequally or interruptedly pinnate to pinnatifid or lyrate [50,54,73,87], with 7-19 leaflets [50,54,73,87], 0.5 to 2 inches (13-50 mm) long [36,50,54], progressively larger toward the apex [54]. There are also typically 1 to 4 small leaves about mid-length on the stem [54,61,73,82].
The stalked flowers [73] are perfect [36,61,62,87,126], 0.3 to 0.4 inch (7-10 mm) long [126] and number from 1 to 9 [36,54,61,73,82,126], but usually 3 [25,73,82]. Styles are long (1 to 2 inches (2.5-5 cm)) and plumose [51,54,123]. The terminal segment of the style is generally persistent in Geum triflorum var. triflorum, while in G.t. var. campanulatum and G.t. var. ciliatum it is generally deciduous [62]. The fruit is a more or less flat [60] achene [36,43,51,54,54,58,60,61,62,70,73,82, 82,87,123,126], 0.1 to 0.5 inches (2.5-12 mm) long [36,54,58,60,61,61].
Old man's whiskers has a thick scaly caudex [36,70]. It also produces short, thick rhizomes [43,50,54,60,73,126].
Old man's whiskers is native to North America and can be found from the Yukon and Northwest Territories, south through British Columbia, Washington and Oregon (mostly east of the Cascades), the Klamath, Cascade and Sierra Nevada Ranges of California, and into northern and central Arizona and northern New Mexico. Its range extends across Canada to Newfoundland. In the United States it is distributed eastward from the Great Basin and Rocky Mountains, across the northern Great Plains and into the prairie region of the Lake States and parts of the Northeast [2,3,6,7,16,21,25,34,36,39,43,48,50,51,54,60,61,62,66,69, 70,73,74,81,87,88,92,95,103,109,120,123,126].
Geum triflorum var. ciliatum occurs in and east of the Cascades from British Columbia to California, east to Alberta and the Rocky Mountain states, probably intergrading with G. t. var. triflorum and G. t. var. campanulatum [4,36,61,62,69,70,82]. According to Great Plains Flora Association [54], a few specimens from the western Great Plains "approach" G. t. var. ciliatum in similarity of diagnostic traits.
Geum triflorum var. campanulatum is apparently a montane ecotype of the Olympic Mountains in Washington, and of Saddle Mountain, Clatsop County, Oregon, transitional to G. t. var. ciliatum [61,62].
Geum triflorum var. canescens is found at higher elevations (8,000 to 9,000 feet (2,400-2,700 m)) in the Sierra Nevada Range and on Hinkey Summit, Santa Rosa Range, northwestern Nevada [69]. Plants Database [121] indicates that G. t. var. canescens also occurs in Washington, Oregon, Idaho, Montana, and Wyoming.
Geum triflorum var. triflorum occurs from Alberta to southeastern Canada and the northeastern U.S., and south in the Rockies, where it more or less straddles the continental divide from Montana to northern New Mexico, and includes some populations as far west as northeastern Arizona [36,50,61,62]. Most Great Plains specimens are G. t. var. triflorum [54].
Plants Database provides state distribution maps of old man's whiskers and its infrataxa.
Fire adaptations: Several studies have documented old man's whiskers population-level responses to fire (see Fire Effects), including postfire increases [6,7,26]. Yet, as of this writing (2006), there is no published information documenting specific plant-level mechanisms by which old man's whiskers responds to fire. Important areas for future inquiry might include, for example, the importance of vegetative (rhizome or caudex) postfire recovery compared with postfire seedling establishment, or the relative influence of fire severity or season of burning on these adaptations.
FIRE REGIMES: As of this writing (2006) there is very little published information that specifically addresses fire regime characteristics that might influence old man's whiskers productivity or distribution. Limited research has suggested that factors such as fire intensity [7] or season [6] may be important (see Fire Effects), but these few studies are too limited in number and scope to provide much clarity or certainty about their effect.
There is also no published information, as of this writing (2006), that indicates the importance of fire return interval for old man's whiskers productivity or distribution. However, it may be inferred from studies of FIRE REGIMES in plant communities and ecosystems where old man's whiskers can be found, that old man's whiskers seems to occur where fire return intervals are relatively short. See the following table, which provides fire return intervals for plant communities and ecosystems where old man's whiskers may occur.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"
Community or ecosystem Dominant species Fire return interval range (years) grand fir Abies grandis 35-200 [10] bluestem prairie Andropogon gerardii var. gerardii-Schizachyrium scoparium <10 [77,99] Nebraska sandhills prairie Andropogon gerardii var. paucipilus-Schizachyrium scoparium 99] silver sagebrush steppe Artemisia cana 5-45 [59,101,128] sagebrush steppe Artemisia tridentata/Pseudoroegneria spicata 20-70 [99] basin big sagebrush Artemisia tridentata var. tridentata 12-43 [106] mountain big sagebrush Artemisia tridentata var. vaseyana 15-40 [11,32,93] Wyoming big sagebrush Artemisia tridentata var. wyomingensis 10-70 ( x=40) [122,129] desert grasslands Bouteloua eriopoda and/or Pleuraphis mutica 10 to <100 [90,99] plains grasslands Bouteloua spp. 99,128] blue grama-needle-and-thread grass-western wheatgrass Bouteloua gracilis-Hesperostipa comata-Pascopyrum smithii 99,105,128] blue grama-buffalo grass Bouteloua gracilis-Buchloe dactyloides 99,128] grama-galleta steppe Bouteloua gracilis-Pleuraphis jamesii 99] cheatgrass Bromus tectorum 100,127] curlleaf mountain-mahogany* Cercocarpus ledifolius 13-1,000 [13,107] western juniper Juniperus occidentalis 20-70 Rocky Mountain juniper Juniperus scopulorum <35 [99] wheatgrass plains grasslands Pascopyrum smithii <5-47+ [99,101,128] Engelmann spruce-subalpine fir Picea engelmannii-Abies lasiocarpa 35 to >200 blue spruce* Picea pungens 35-200 [10] pinyon-juniper Pinus-Juniperus spp. <35 [99] Rocky Mountain bristlecone pine P. aristata 9-55 [41,42] whitebark pine* Pinus albicaulis 50-200 [1,8] Rocky Mountain lodgepole pine* Pinus contorta var. latifolia 25-340 [17,18,119] Sierra lodgepole pine* Pinus contorta var. murrayana 35-200 [10] Colorado pinyon Pinus edulis 10-400+ [47,53,71,99] Pacific ponderosa pine* Pinus ponderosa var. ponderosa 1-47 [10] interior ponderosa pine* Pinus ponderosa var. scopulorum 2-30 [10,15,83] Arizona pine Pinus ponderosa var. arizonica 2-15 [15,35,112] galleta-threeawn shrubsteppe Pleuraphis jamesii-Aristida purpurea <35 to <100 eastern cottonwood Populus deltoides <35 to 200 [99] quaking aspen-paper birch Populus tremuloides-Betula papyrifera 35-200 [44,124] quaking aspen (west of the Great Plains) Populus tremuloides 7-120 [10,56,91] mountain grasslands Pseudoroegneria spicata 3-40 ( x=10) [9,10] Rocky Mountain Douglas-fir* Pseudotsuga menziesii var. glauca 25-100 [10,11,12] California mixed evergreen Pseudotsuga menziesii var. menziesii-Lithocarpus densiflorus-Arbutus menziesii <35 [10] bur oak Quercus macrocarpa <10 [124] oak savanna Quercus macrocarpa/Andropogon gerardii-Schizachyrium scoparium 2-14 [99,124] little bluestem-grama prairie Schizachyrium scoparium-Bouteloua spp. <35 [99] mountain hemlock* Tsuga mertensiana 35 to >200 [10] *fire return interval varies widely; trends in variation are noted in the species reviewBiogeographic: The published literature describes a variety of site types where old man's whiskers may be found. These include, but may not be limited to: montane, alpine or high valley grasslands, meadows, balds and tundra [2,36,51,69,82]; sometimes rocky and often open mountain slopes, hillsides, and foothills [69,70,82,87]; western grasslands and sagebrush (Artemisia spp.) plains [24,25,28,39,51,60,61,66,75,82,84,85, 109]; Missouri River bottomlands [3]; Great Plains and Midwestern prairie and grasslands [5,6,21,30,37,54,64,95,123]; old fields [16]; woodlands and open forests [7,51,54,60,69,70,82,85,123].
Elevation: Old man's whiskers is found at a range of elevations, from the subalpine and alpine zones of the western mountains [43,61,81,82,86], to Great Lakes prairies [95,123], and old fields in the New Jersey Piedmont [16]. In the mountainous West its elevation range might be quite broad. For instance, Lackschewitz [81] described old man's whiskers habitat in west-central Montana from valley bottoms to upper subalpine, and Hitchcock and Cronquist [61] indicated that it could be found from the lower foothills to subalpine ridges in the Pacific Northwest.
The following table lists published accounts of elevation ranges where old man's whiskers can be found in western North America. These examples should not necessarily be interpreted as elevational limits to old man's whiskers distribution, but simply as a demonstration of the kinds of elevations, particularly upper elevations, where old man's whiskers might occur.
Location Elevation Colorado 7,000 to 11,000 feet (2,100-3,400 m) [58] Intermountain West 5,200 to 11,000 feet (1,600-3,400 m) [36] east-central Arizona 10,400 to 10,900 feet (3170-3320 m) [2] California 4,300 to 10,500 feet (1,300-3,200 m) [60] Uinta Basin (Utah) 7,500 to 10,000 feet (2300-3050m) [51] Greater Yellowstone 6,800 to 10,000 feet (2,070-3050 m) [39] southern Montana above 9,800 feet (>3000 m) [20] Arizona (Geum triflorum var. ciliatum) 6,000 to 9,500 feet (1,800-2,900 m) [70] northern New Mexico 7,000 to 9,000 feet (2,100-2,700 m) [87] northwestern Wyoming 6,700 to 9,000 feet (2,040-2,700 m) [28] Nevada (G. t. var. canescens) 8,000 to 9,000 feet (2,400-2,700 m) northern Nevada (G. t. var. ciliatum) 5,000 to 8,000 feet (1,500-2,400 m) [69] British Columbia 3,480 to 7,434 feet (1,060-2,266 m) [73] southeastern Oregon (G. t. var. ciliatum) 6,000 to 7,000 feet (1,800-3,400 m) [4] northern Idaho to 2,900 feet (880 m) [7]Climate: While to date (2006) there is no comprehensive source for climate parameters describing the distribution of old man's whiskers, the following examples provide some indication of climate for habitats where old man's whiskers occurs. At a south-central Saskatchewan prairie site, mean monthly temperatures range from -0.4 °F (-18 °C) in January to 66 °F (19 °C) in July, and average annual precipitation is 14 inches (360 mm), 30% falling as snow [6]. A northern Idaho ponderosa pine (Pinus ponderosa) habitat receives an average of 22 inches (560 mm) of annual precipitation, mostly falling from October to March [7]. A study site in the upper Blackfoot Valley in western Montana receives an average of about 16 inches (400 mm) of precipitation annually, nearly a third occurring in May and June [24]. A southeastern Oregon montane habitat containing a population of G. t. var. ciliatum has an average frost-free period of 10-50 days and annual precipitation estimated at 12-18 inches (300-460 mm), about 40% occurring in the growing season [4].
Moisture regime: The site characteristic that is perhaps most frequently mentioned in relation to old man's whiskers occurrence is moisture regime. In the more arid regions of western North America, old man's whiskers habitat is usually characterized as moist or wet. This is particularly true where old man's whiskers is found in isolated moist areas surrounded by a wider landscape of dry habitat. Some examples include wet alpine meadows in Nevada [69], more mesic areas of sagebrush-dominated plains and lower foothills in the Pacific Northwest [61], moist streambanks and wet meadows in high valley and montane sites in the Intermountain West [36], and moist slopes in Colorado [58].
In grassland habitats of the northern Rockies, several studies have documented old man's whiskers's affinity for moister areas. A study of grassland phytogeography along the North Fork Flathead River in Glacier National Park, northwestern Montana, indicated that while old man's whiskers was present in most grassland habitats studied, it became increasingly more prevalent towards the mesic end of the moisture gradient in habitats dominated by rough fescue (Festuca altaica) [75]. In an Idaho fescue/bluebunch wheatgrass habitat type in western Montana, old man's whiskers is among several species that were more likely to be prominent in the moister Columbia needlegrass (Achnatherum nelsonii) phase, compared with other phases of the habitat type [96]. A study in southwestern Montana mountain grasslands, comprised of variations of an Idaho fescue-bluebunch wheatgrass habitat type, indicated greater old man's whiskers productivity where moisture availability was greatest. Mean old man's whiskers aboveground biomass productivity was 7 lb/ac (range 2-13) on a southwest exposure (typical Idaho fescue-bluebunch wheatgrass habitat type), compared with 98 lb/ac (range 45-139) on a northeast exposure (Columbia needlegrass phase of the same habitat type). It was suggested that the northeast exposure had greater moisture availability during the growing season [97]. However, old man's whiskers presence is probably reduced on sites where snowpack lasts into summer (Weaver 1970 as cited in [94]).
Conversely, where grassland habitats persist within a larger landscape of moister, often forested habitats, old man's whiskers sites are typically characterized as dry. These areas are most common along the prairie/forest interface in the midwestern and north-eastern U.S. and Canadian prairie provinces. Some examples include isolated dry grasslands in Wood Buffalo National Park, northern Alberta [109], dry prairie sites along the forest-prairie transition zone in north-central Minnesota [30], dry prairies in northern Illinois [95], xeric prairie habitats in Wisconsin [37], and "dry habitats" in Michigan [123]. A similar situation may be found in western North America where dry, grassy isolates occur within a larger, moister forested matrix. For instance, Franklin and Dyrness [48] noted the presence of old man's whiskers on steep, south-facing slopes in the Olympic Mountains, northwestern Washington.
In some areas, old man's whiskers may occur locally within a relatively wide range of moisture regimes. Lackschewitz [81] indicated that old man's whiskers occurs on sites that are mesic (adequate moisture during all or most of the growing season, but rarely if ever flooded) to meso-xeric (moisture abundant in the early growing season but dry later on) sites in west-central Montana. According to Klinkenberg [73] old man's whiskers can be found within dry to mesic grasslands, meadows, rocky slopes and open forests in the steppe, montane and subalpine zones of British Columbia. Lloyd and others [85] indicated that old man's whiskers is found from xeric to subhydric soil moisture regimes within the bunch grass, Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca), and montane spruce (Picea spp.) zones in the Kamloops Forest Region, southern British Columbia.
Soils: Although as of this writing (2006) there is no comprehensive information on old man's whiskers soil affinities, it appears from several sources that old man's whiskers occurs on a wide variety of soils. For example, it is found on heavy clay soils in northern Nevada [69], as well as moist, well-drained soils in the Uinta Basin of northeastern Utah [51].
Limited published information suggests that old man's whiskers is probably not an important forage species for domestic livestock. Kearney and others [70] indicated it may provide forage for domestic sheep. Cattle were not observed grazing old man's whiskers while on summer range on lower slopes of the Elkhorn Range, west-central Montana [52].
A smattering of published information provides little in the way of definitive conclusions about the response of old man's whiskers to domestic livestock grazing. Old man's whiskers was labeled an "increaser" in response to grazing on Montana rangelands by Mueggler and Stewart [96] and Montana State University Extension Service [80]. Daubenmire [38] considered prairie smoke a "decreaser" in response to grazing within the Idaho fescue-common snowberry (Symphoricarpos albus) habitat type in eastern Washington. In a rough fescue/bluebunch wheatgrass habitat type in western Montana, Mueggler and Stewart [96] indicated that prairie smoke increases with "light" grazing, but declines with "heavy use," particularly by domestic sheep.
While old man's whiskers is probably utilized by native ungulates, at least seasonally, it appears not to be a major forage source. Gordon [52] reported elk utilization of small amounts of old man's whiskers as winter forage (1% of diet during January-March) on lower slopes of the Elkhorn Range, west-central Montana. Old man's whiskers grazing by elk was not observed on these sites during spring (April-May). Kamps [65] recorded evidence of mule deer feeding on old man's whiskers in central Montana, mainly in spring, and Singer [114] documented spring utilization by white-tailed deer in the North Fork area of Glacier National Park, Montana. Hansen and others ([57] and references therein) ranked old man's whiskers "food value" as "poor" for elk, mule deer, pronghorn, upland game birds, waterfowl, small nongame birds, and small mammals, and "fair" for white-tailed deer in southwestern Montana.
Palatability/nutritional value: Old man's whiskers does not seem particularly palatable or nutritious for livestock. Hansen and others ([57] and references therein) ranked old man's whiskers "energy value" and "protein value" as "poor." Palatability was considered "poor" for cattle and horses and "fair" for domestic sheep ([57] and references therein). Mueggler and Stewart [96] characterized old man's whiskers as having "very poor" palatability for cattle, domestic sheep, deer, and elk. Gross energy value of old man's whiskers seeds, in average gram-calories per gram, were 4,998 for whole and 5,693 for hulled seeds [72].
Cover value: No information is available on this topic.
Vegetation classifications describing plant communities where old man's whiskers is a dominant species
are:
AB:
prairie Junegrass (Koeleria macrantha)-old man's whiskers [118]
WY:
mountain big sagebrush (Artemisia tridentata ssp. vaseyana)/needle-and-thread grass
(Hesperostipa comata)-old man's whiskers
mountain big sagebrush/Idaho fescue (Festuca idahoensis)-old man's whiskers
mountain big sagebrush/bluebunch wheatgrass (Pseudoroegneria spicata)-prairie
smoke [28]
CA:
stemless goldenweed (Stenotus acaulis)-G. t. var. canescens [86]
Old man's whiskers phenology may vary according to site conditions. A study of variation in plant seasonal development on a southwestern Montana mountain grassland site showed that old man's whiskers phenological development initiated earlier and proceeded more rapidly, on average, on a southwest exposure compared with a northeast exposure [97]. Hitchcock and Cronquist [61] indicated that flowering occurred from April to early August in the Pacific Northwest, depending on elevation.
Some examples of flowering phenology from across old man's whiskers's North American range are:
Location Approximate flowering times south-central Wisconsin [5] mid-May-early June Uintas (northeastern Utah) [51] May-June Pacific Northwest [61] April-early August Intermountain West [36] June-August Great Plains [54] April-June northern New Mexico [87] May-June Arizona [70] May-August northern Illinois [95] May-June western New York to Minnesota and Iowa [50] May-June (Geum triflorum var. triflorum) Beartooth Plateau, southern Montana [20] late June-July southern Wisconsin, northern Illinois [40] May-late JuneCurtis [37] indicated that old man's whiskers was among the earliest plants to flower on xeric prairie sites in Wisconsin.
The following old man's whiskers flowering data were collected over 6 seasons near Woodworth, central North Dakota [33].
Earliest 1st bloom Latest 1st bloom Median date of full flowering Median date when flowering 95% complete Mean # days in flower May 10 1983 June 6, 1979 May 22 June 19 37The following old man's whiskers flowering data were collected over 13 seasons at Swift Current, southwestern Saskatchewan [29].
Mean flowering date Earliest flowering date Latest flowering date Latest date in flower Mean # days in flower May 13 April 24, 1946 May 25, 1954 August 1 62Old man's whiskers regenerates from seeds, rhizomes, and probably by sprouting from the caudex. However, as of this writing (2006) there is very little published information describing old man's whiskers regeneration processes.
Pollination: No information is available on this topic.
Breeding system: Given that the flowers are perfect [36,61,62,87,126], old man's whiskers is also monoecious.
Seed production: Stevens [116] collected 142 seeds from a single "mature" old man's whiskers plant "of average size," "growing where competition was low."
Seed dispersal: Fruits are wind-dispersed [123]. Zimmerman [130] noted that "seed heads do not all ripen together...., yet suddenly and individually fall off, especially during rainstorms."
Seed banking: No information is available on this topic.
Germination: Germination is probably variable, depending on conditions, but not dependent upon stratification. Zimmerman [130] suggested that old man's whiskers seeds do not require stratification, and can germinate soon after dispersal. Baskin and Baskin [19] also provided qualified support for the idea that seeds are nondormant at maturity. Greene and Curtis [55] conducted germination tests on a variety of Wisconsin prairie species. Stratification for 3 months appeared to have little effect on prairie smoke germination, with 64% of stratified seeds germinating compared with 50% for unstratified.
Old man's whiskers seed viability may be variable from year to year. Unstratified seed collected in southern and western Wisconsin in 1937, 1940, and 1941, yielded germination rates of 80%, 14%, and 50%, respectively [55]. Germination testing on old man's whiskers seed collected from an eastern South Dakota prairie resulted in a 90% germination rate, requiring 7-16 days [115]. Zimmerman [130] suggested that old man's whiskers seeds do require prolonged wetting prior to germination [130].
Seedling establishment/growth: As of this writing (2006) there is very little published information describing old man's whiskers seedling establishment and growth. A study of the effects of pocket gopher disturbance on shortgrass prairie forbs suggests that old man's whiskers seedling establishment and growth may be enhanced by small-scale disturbance [88].
Asexual regeneration: Several sources indicate that old man's whiskers has both rhizomes [43,50,54,60,73,126] and a caudex [36,70], suggesting that asexual regeneration can occur. However, there is currently (2006) very little published information describing the importance of asexual regeneration for its survival and spread. Curtis [37] wrote that old man's whiskers was among several species "with a strongly developed rhizome method of vegetative propagation."
Although research describing the relative benefit to old man's whiskers provided by fire-caused disturbance appears ambiguous (see Fire Effects), several studies suggest old man's whiskers presence may be enhanced by other types of disturbance. Bramble-Brodahl [28] classified the sagebrush-grass vegetation of the Gros Ventre District of the Bridger-Teton National Forest. In the mountain big sagebrush/Idaho fescue-old man's whiskers habitat type, old man's whiskers was among species said to increase with disturbance. In the mountain big sagebrush/needle-and-thread grass-old man's whiskers habitat type, old man's whiskers was among species said to increase with disturbance on wetter sites [28]. Redmann and Schwartz [103] studied the dry grassland vegetation of Wood Buffalo National Park, Alberta. Sampling at 4 paired sites indicated that old man's whiskers had greater presence on sites disturbed by "compaction and erosion", compared with undisturbed sites [103]. A study of the effects of pocket gopher disturbance on shortgrass prairie forbs indicated that old man's whiskers benefits from small-scale disturbance. Comparisons of undisturbed habitat and habitat disturbed by pocket gopher burrowing indicated that old man's whiskers seedling establishment and growth were greater on pocket gopher mounds [88].
Since old man's whiskers seems to benefit from disturbance, it is most likely to be found in association with early-successional rather than late-successional communities. Bunting and others [31] provided some support for this idea in a study of the western juniper (Juniperus occidentalis)/mountain big sagebrush mosaic of the South Fork Owyhee River, southwestern Idaho. Old man's whiskers was among several forb species associated primarily with early-successional grassland and sagebrush steppe within this mosaic. These species were not typically found in late-successional juniper (Juniperus spp.) woodland communities [31].
The currently accepted scientific name of old man's whiskers is Geum triflorum Pursh.(Rosaceae)
[25,36,43,50,51,54,60,61,62,63,68,69,70,73,81,82,87,95,126]. The following varieties are recognized:
G. triflorum var. campanulatum (Greene) C.L. Hitchc. [61,62,68]
G. triflorum var. canescens (Greene) Kartesz & Gandhi [67,68,69]
G. triflorum var. ciliatum (Pursh) Fassett [48,54,61,62,68,69,70,82,87,126]
G. triflorum var. triflorum [50,54,61,62,68,73]
For the purposes of this review, the common name "old man's whiskers" is used when discussing
characteristics common to (or assumed to be common to) the species in general. When referring to
infrataxa, the scientific names for the varieties listed above are used.