This description covers characteristics that may be relevant to fire ecology and is not meant for identification. Keys for identification are available (for example, [8,10,13,14,15,35]).
Small-leaf pussytoes is a stoloniferous, mat-forming, perennial forb [10,34,35]. Stems are 1.2 to 6.0 inches (3-15 cm) long. Leaves are simple, alternate, and mostly basal. Cauline leaves are reduced upwards. The inflorescence is a large, closely aggregated cyme with 2 to 6 heads. The fruit is a small achene with a bristly pappus [11,13,14,22,35]. One-year-old plants in Missoula, Montana, had fibrous vertical and horizontal roots diverging from stolons (see photo above). Some stolons had grown beneath the littler layer (Fryer 2001 personal observation).
States and provinces (as of 2011 [32]):
United States: AZ, CA, CO, ID, KS, MI, MN, MT, ND, NE, NM, NV, OK, OR, SD, TX, UT, WA, WY
Canada: AB, BC, MB, ON, SK
Small-leaf pussytoes is rare in Ontario, Minnesota, Michigan, Washington, Oklahoma, and Texas [15]. It has not been reported in California since 1987, and it may not occur there [31].
Fire adaptations: Pussytoes (Antennaria spp.) colonize bare mineral soil from light, wind-dispersed seed [28]. The seeds are easily dispersed, so small-leaf pussytoes may establish on burns from on- or off-site seed sources.
Plant response to fire: Several studies suggest that small-leaf pussytoes can survive low-severity fire and may regain postfire cover slowly after severe fire, although the specific mechanisms of postfire recovery (sprouting from the root crown and/or establishing from seed) had not been studied as of 2011. Top-killed small-leaf pussytoes probably sprout from the caudex. A study confirming a soil-stored seedbank for small-leaf pussytoes [16] suggests that small-leaf pussytoes may also establish from on-site, soil-stored seed after fire. It may also establish from off-site, wind-dispersed seed.
Bataineh and others [2] found that 8 years after the 1972 Rattlesnake Wildfire on the Coconino National Forest, Colorado, small-leaf pussytoes was dominant on plots where fire severity was low, but it was not reported on high-severity plots. On a site that escaped the 1972 wildfire but was burned under prescription in 1977, small-leaf pussytoes was dominant by postfire year 3. More than 30 years after fire, small-leaf pussytoes was among the 5 most dominant species on both wildfire- and prescribed-burned plots [2].
On the Lubrecht Experimental Forest in western Montana, pussytoes (Antennaria spp.), including small-leaf pussytoes, were among the most common forbs on prescribed-burned plots and on thinned plots in ponderosa pine/Douglas-fir forests [21]. Fire severity was low to moderate. Pussytoes cover on burned plots increased slowly over 3 postfire years. See the Research Project Summary of this study for details on the fire prescription, fire behavior, and responses of pussytoes and more than 100 other plant species.
In Bataineh and others' study, small-leaf pussytoes was an important forb on plots designed to test the responses of understory species to varying-interval (1, 2, 4, 6, and 10 years), low-severity prescribed fires in interior ponderosa pine forests. Forb cover did not differ significantly with fire-return interval. Although the responses of individual forbs were not described, small-leaf pussytoes was among the most common forbs on burned plots [25,26].
Small-leaf pussytoes' absence from severely burned plots after the Rattlesnake Wildfire [2] suggests that it is killed by severe fire. It may establish from on- or off-site seed after fire kill, however. Seventeen years after the mixed-severity Waterfalls Canyon Wildfire in Grand Teton National Park, Wyoming, small-leaf pussytoes was present in trace amounts on severely burned sites [9]. Its absence in earlier postfire years suggests that it established from seed; prefire vegetational composition was not reported.
After a low-severity spring prescribed fire in Jasper National Park, Alberta, small-leaf pussytoes cover was less on open-canopy sites with elk grazing than on closed-canopy sites or ungrazed, open-canopy sites. The plant community was an open lodgepole pine community [1].
Small-leaf pussytoes cover (%) under closed and open canopies before fire (1998) and in postfire year 2 (2001) [1] Closed canopy Open canopy Year 1998 2001 1998 2001 No exclosure 1.2 1.8 11.0 3.3* Exclosure 1.0 0.5 3.0 1.5 *Significant difference between years at PTaylor [30] reported that small-leaf pussytoes was present in lodgepole pine stands in Yellowstone National Park that had burned more than 100 years previously. Its cover was sparse, and it was found only in the oldest stands [30].
As of 2011, there was no published information on the immediate effect of fire on small-leaf pussytoes. Severe fire likely kills small-leaf pussytoes plants, while low- [2,21,25,26] and possibly moderate-severity [21] fire likely top-kills small-leaf pussytoes plants. Because small-leaf pussytoes' stolons lie on the soil surface, most fires probably kill them, while root crowns insulated with soil probably survive most fires.
There was no information on the effects of fire on small-leaf pussytoes seeds as of 2011.
Grazing animals apparently make little use of small-leaf pussytoes. Lepidopterans consume the seeds [22].
Palatability and nutritional value: The palatability of small-leaf pussytoes is poor for cattle, domestic sheep, and horses. Small-leaf pussytoes is rated poor in protein and energy value [7].
Cover value: No information is available on this topic.
Site characteristics: Small-leaf pussytoes is found on open plains and prairies, in open forests, dry meadows, and pastures, and along roadsides [8,11,13,18]. It grows well on gentle slopes but not on steep slopes. Best grow is on loam-, clayey loam-, and clay-textured soils. Growth is poor on gravel, sand, and dense clay [7]. In west-central Montana, small-leaf pussytoes occurs in mountain grassland valleys in moist to dry soils [17]. It occurs at mid- to high elevations [7]:
Small-leaf pussytoes elevational ranges in several western states [7] State Elevation (feet) Colorado 5,000-12,000 Montana 3,300- 6,000 Utah 5,400-10,700 Wyoming 4,300- 8,400Plant communities: In the western United States, small-leaf pussytoes occurs in sagebrush (Artemisia spp.), pinyon-juniper (Pinus-Juniperus spp.), mountain grassland, ponderosa pine (P. ponderosa), Douglas-fir (Pseudotsuga menziesii), lodgepole pine (P. contorta), fir-spruce (Abies-Picea spp.), and quaking aspen (Populus tremuloides) communities [18,28,35].
In the Great Lakes, small-leaf pussytoes occurs on dunelands and dry prairies and oak (Quercus spp.) savannas [22].The currently accepted scientific name of small-leaf pussytoes is Antennaria parvifolia Nutt. (Asteraceae) [8,10,14,15,34,35].
Small-leaf pussytoes apparently hybridizes with umbrinella pussytoes (A. umbrinella) [5]. It is sometimes lumped with littleleaf pussytoes (A. microphylla), but the 2 species are probably not closely related [10].
Antennaria parvifolia is a species of flowering plant in the family Asteraceae, known by the common names small-leaf pussytoes and Nuttall's pussytoes (not to be confused with littleleaf pussytoes). It is native to western and central North America.
Antennaria parvifolia generally grows a few centimeters high but it may reach 15 cm (6 inches).[3] The grayish, woolly-haired leaves are up to 3.5 cm (1+1⁄2 in) long, the upper ones shorter and narrower than the basal. The inflorescence contains 2 to 7 flower heads, each about 1.5 cm (1⁄2 in) across and blooming from July and September.[3] The plant may be gynoecious, containing only female flowers, or dioecious, with some female plants and some male in a given population. Dioecious plants are most common in Colorado and New Mexico,[4] and can reproduce sexually, though male plants are much less common than female.[5] Plants in most other areas are mostly gynoecious, reproducing asexually via apomixis.[4] The plant forms mats by spreading stolons and sprouting new stems.[5] The flower heads are lined with an outer layer of phyllaries which are translucent except at the base, where they vary from white, red, green, and brown.[3][4] The fruit is an achene with a pappus that helps it disperse on the wind.[4]
Features that distinguish the species from other members of Antennaria include the clustered basal leaves and the near absence of dark bases on the backs of the flower bracts.[3]
The species is native to western and central North America and widespread in Canada, the United States, and northern Mexico—from British Columbia east to Ontario and south to California, Chihuahua, and Nuevo León.[4][6][7] It has not been observed in California since 1987.[5]
It can be found in open and dry areas such as plains and openings in forests.[3]
In Colorado, the species is an indicator of overgrazing and increases in frequency on heavily grazed land. It grows in disturbed habitat and a wide variety of ecosystems and soil types.[5]
Some forms of the small-leaf pussytoes are considered excellent groundcovers, particularly by gardeners of the American great plains. They prefer to grow in the open in more northerly areas like North Dakota and at higher elevations, but prefer partial shade in more southerly locations such as Texas or lower altitudes. They are valued for their handsome foliage, their spring flowers, and for their lack of an aggressive nature in even the most ideal of garden conditions.[8] They require a well drained soil, but may struggle in hot areas in sandy soils.[8] They are cold hardy to USDA zones 4 (as cold as -34°C).[9]
Antennaria parvifolia is a species of flowering plant in the family Asteraceae, known by the common names small-leaf pussytoes and Nuttall's pussytoes (not to be confused with littleleaf pussytoes). It is native to western and central North America.
Antennaria parvifolia là một loài thực vật có hoa trong họ Cúc. Loài này được Nutt. mô tả khoa học đầu tiên năm 1841.[1]
Antennaria parvifolia là một loài thực vật có hoa trong họ Cúc. Loài này được Nutt. mô tả khoa học đầu tiên năm 1841.
