Shaggy fleabane (Erigeron pumilus)

Nomenclature

Shaggy fleabane (Erigeron pumilus Nutt.) belongs to the Astereae tribe of the Asteraceae family (Semple 1985; Nesom 2006; USDA NRCS 2021).

Family

Asteraceae – Aster family

Genus

Erigeron

Species

pumilus

NRCS Plant Code

ERPU2 (USDA NRCS 2021)

Subtaxa

Flora of North America recognizes two varieties of shaggy fleabane: E. p. var. intermedius (Cronquist) Cronquist and E. p. var. pumilus Nutt. (Nesom 2006; ITIS 2021). These subtaxa are referred to as subspecies by PLANTS database (USDA NRCS 2021). Utah Flora (Welsh et al. 2016) considers E. p. var. concinnus (Hook. & Arn.) Dorn to be a subtaxa of shaggy fleabane and the most common type of shaggy fleabane in Utah, but this variety is recognized as its own species by Flora of North America (Nesom 2006) and PLANTS (USDA NRCS 2021).

Synonyms

E. p. subsp. concinnoides Cronquist, E. p. subsp. intermedius Cronquist, E. p. subsp. intermedius var. gracilior Cronquist, E. p. subsp. intermedius var. intermedius (Cronquist) Cronquist, E. p. subsp. pumilus Nutt., E. p. subsp. typicus Cronquist, E. p. var. concinnus (Hook. & Arn.) Dorn, E. p. var. condensatus (D.C. Eaton) Cronquist, E. p. var. gracilior Cronq. euconcinnoides Cronquist, E. p. var. euintermedius Cronquist, and E. p. var. subglaber Cronquist (ITIS 2021).

Common Names

Dwarf fleabane, hairy fleabane, low daisy, shaggy daisy, and Vernal daisy (Andersen and Holmgren 1976; Weber 1976; Taylor 1992; Welsh et al. 2016; USU Ext. 2017).

Chromosome Number

Chromosome numbers are: 2n = 18, 36 according to Semple (1985) and Hickman (1993). Chromosome numbers are 2n = 18, 36 for variety intermedius (Nesom 2006). Welsh et al. (2016) reported chromosome numbers of 2n = 27 for the species, but this was not reported elsewhere.

Hybridization

Hybrids were not reported in the reviewed literature.

Distribution

Shaggy fleabane occurs from southern British Columbia south through the Cascade Mountains of Washington and Oregon to central and eastern California and west to North Dakota, South Dakota, Nebraska, and Kansas (Nesom 2006; Hitchcock and Cronquist 2018; USDA NRCS 2021). According to PLANTS (USDA NRCS 2021), shaggy fleabane also occurs in Manitoba and a handful of counties in Arizona and New Mexico. Shaggy fleabane appeared in 29 of 50 local floras from throughout the Basin and Range and Colorado Plateau physiographic provinces (McLaughlin 1986).

Variety intermedius is the more westerly distributed shaggy fleabane variety. It occurs from southern British Columbia south to southern California and east to Utah, Wyoming, and Montana (Nesom 2006; Hitchcock and Cronquist 2018; USDA NRCS 2021). Variety intermedius occurs in the San Juan River drainage of Utah but does not occur in the bordering areas of Colorado, Arizona, or New Mexico (Heil and O’Kane 2003).

Variety pumilus is the more easterly distributed shaggy fleabane variety, occurring primarily on the east side of the Rocky Mountains and in the Great Plains. It occurs in Alberta and Saskatchewan and south to Kansas and Colorado with a disjunct population in Washington (Hickman 1993; Nesom 2006; Hitchcock and Cronquist 2018). Shiflet (1994) and Heil and O’Kane (2003) report variety pumilus in Arizona and New Mexico, and PLANTS (USDA NRCS 2021) reports this variety in Manitoba as well.

Habitat And Plant Associations

Throughout its range, shaggy fleabane commonly grows in dry open sites in grassland (Fig. 1), sagebrush (Artemisia spp.), pinyon-juniper (Pinus–Juniperus spp.), and ponderosa pine (P. ponderosa) communities (Munz and Keck 1973; Shiflet 1994; Nesom 2006; Pavek et al. 2012; Charboneau et al. 2013; Welsh et al. 2016; USU Ext. 2017; Hitchcock and Cronquist 2018).

Grasslands. Shaggy fleabane is common in the bluebunch wheatgrass (Pseudoroegneria spicata) rangeland cover type, which occurs throughout the Pacific Northwest. Bluebunch wheatgrass communities average 8 to 20 in (203–508 mm) of annual precipitation, 45 to 60% of which occurs in the winter. Summers are very dry (Shiflet 1994). In the Columbia Basin in Washington and Oregon, constancy of shaggy fleabane was 62% in bluebunch wheatgrass/Sandberg bluegrass (Poa secunda) grasslands (Franklin and Dyrness 1973). A bluebunch wheatgrass-Sandberg bluegrass-shaggy fleabane community occupied hot, dry sites in the Blue Mountains of southeastern Washington, northeastern Oregon, and west-central Idaho (Powell et al. 2007). In the Snake River Canyon in Idaho and adjacent Washington and Oregon, shaggy fleabane constancy was 55% in wheatgrass-plains pricklypear (Agropyron spp./Opuntia polyacantha) communities on southwest slopes, 44% in Idaho fescue (Festuca idahoensis)/wheatgrass grasslands on northeastern slopes, and 33% in wheatgrass–Sandberg bluegrass grasslands on western slopes and in Idaho fescue/prairie Junegrass (Koeleria macrantha) grasslands on northeastern slopes (Tisdale 1979). In southern Saskatchewan, shaggy fleabane occurred in rough fescue (F. campestris) mixed prairie (Coupland and Brayshaw 1953).

Figure 1. Shaggy fleabane (lower right) growing in a grassland community in Oregon used as a seed collection area by the Bureau of Land Management’s (BLM) Seeds of Success program. Photo: BLM OR0303, SOS.

Shrublands. Shaggy fleabane is most common in low- to moderate-elevation sagebrush shrublands and occurs in salt desert and mountain brush communities (Fig. 2) (Cronquist 1947; Munz and Keck 1973; Andersen and Holmgren 1996; Welsh et al. 2016; Hitchcock and Cronquist 2018). Although it occurs throughout the sagebrush steppe, it rarely occurs in high densities (Taylor 1992).

Shaggy fleabane was reported as a common forb in several shrub-dominated rangeland cover types across the United States (Shiflet 1994). It occurs in dry basin big sagebrush (A. tridentata subsp. tridentata) types, which occur below 7,000 ft (2,000 m) in eastern Washington, southern Idaho, Montana, Wyoming, and south to Arizona and New Mexico. It occurs in Wyoming big sagebrush (A. t. subsp. wyomingensis) communities, which occupy a range like that of basin big sagebrush communities but includes parts of Colorado, Nevada, and northeastern California. Shaggy fleabane grows in threetip sagebrush (A. tripartita) shrublands of relatively high-elevation sites (4,000–9,000 ft [1,200–2,700 m]) in Washington, eastern Oregon, southern Idaho, southwestern Montana, Wyoming, and northern Utah and Nevada. It occurs in black sagebrush (A. nova) communities found at middle elevations in southern Idaho, western Wyoming, Colorado, Utah, and Nevada (Shiflet 1994). When forb species composition was evaluated at 15 big sagebrush (A. tridentata)-dominated sites in Oregon, Nevada, Idaho, Utah, Colorado, Wyoming, and Montana, shaggy fleabane was sampled at 6 sites (Pennington et al. 2017).

Figure 2. Shaggy fleabane growing in a big sagebrush shrubland in Oregon. Photo: BLM OR0303, SOS.

Constancy of shaggy fleabane was 100% in big sagebrush/Idaho fescue, 42% in threetip sagebrush/Idaho fescue, and 40% in antelope bitterbrush (Purshia tridentata)/Idaho fescue vegetation in the Columbia River Basin of Washington and Oregon (Franklin and Dyrness 1973). In Utah, shaggy fleabane often occurs with lupines (Lupinus spp.) in dry, open big sagebrush sites from valleys to upper elevation foothills (USU Ext. 2017). When low sagebrush (A. arbuscula) and black sagebrush habitats were evaluated in northern and central Nevada, shaggy fleabane only occurred in black sagebrush communities (Beatley 1976). Constancy of shaggy fleabane was 100% in black sagebrush-beardless wheatgrass (Pseudoroegneria spicata subsp. inermis) communities in Nye County (5,900–6,900 ft [1,800–2,100 m]) and 80% in black sagebrush-needle-and-thread (Hesperostipa comata) communities in White Pine County (5,900–7,200 ft [2,000–2,200 m]) (Zamora and Tueller 1973). At the Nevada Test Site and in central and southern Nevada, shaggy fleabane grows with saltbush (Atriplex spp.), blackbrush (Coleogyne ramosissima), black sagebrush, and mixed sagebrush–pinyon–juniper communities (Beatley 1976).

Woodlands/Forests. Shaggy fleabane commonly occurs in pinyon-juniper, Utah juniper (J. osteosperma), and ponderosa pine forests throughout its range (Munz and Keck 1973; Charboneau et al. 2013; Welsh et al. 2016; USU Ext. 2017). In southeastern Wyoming’s Medicine Bow National Forest, shaggy fleabane occurred in ponderosa pine-sagebrush communities from 7,880 to 9,250 ft (2,400–2,820 m) (Lukas et al. 2012).

Elevation

Shaggy fleabane occupies elevations from 2,690 to 9,700 ft (1,000–2,960 m) (Nesom 2006; Welsh et al. 2016). In Utah, the elevation range is 2,690 to 9,700 ft (820–2,960 m) (Welsh et al. 2016); in California it is 4,000 to 7,000 ft (1,200–2,100 m) (Munz and Keck 1973; Hickman 1993); and in central and southern Nevada it is 4,000 to 8,200 ft (1,200–2,500 m) (Beatley 1976). Nesom (2006) reports similar elevation ranges for variety intermedius (4,000–9,200 ft [1,200–2,800 m]) and variety pumilus (3,300–8,500 ft [1,000–2,600 m]).

Soils

Shaggy fleabane grows on a variety of substrates and commonly occurs on well-drained sandy to gravelly soil textures (Fig. 3) (Taylor 1992; Welsh et al. 2016; USU Ext. 2017).

Figure 3. Shaggy fleabane growing with grasses and other forbs on a rocky site in Utah. Photo: BLM UT080, SOS.

Texture, substrate, depth. Shaggy fleabane is a typical forb in several dry rangeland cover types with shallow to deep soils. Basin big sagebrush communities receive low levels of precipitation (8–14 in [203–356 mm]/yr) and occupy deep permeable soils. Wyoming big sagebrush cover types occupy shallow soils, which often overlay hardpan or parent rock and receive even lower levels of precipitation (7–12 in [178–305 mm]/yr). Black sagebrush cover types occupy droughty, coarse-textured, usually calcareous soils, which are often shallow or overlay silica hardpan but when deeper have an extremely gravelly subsoil. Black sagebrush cover types receive 8 to 16 in (203–406 mm) annual precipitation (Shiflet 1994).

In the Snake River Canyon in Idaho and adjacent Washington and Oregon, shaggy fleabane occurs in grasslands and shrublands where soils average 21 to 33 in (54–85 cm) deep and have 2 to 7% organic matter and 6 to 43% gravel or rock cover (Tisdale 1979). Bluebunch wheatgrass-Sandberg bluegrass-shaggy fleabane communities at 1,500 to 2,600 ft (460–790 m) in the Snake River Canyon in the Wallowa-Whitman National Forest occur on steep (average 57%) southeast to northwestern slopes. These communities occupy sandy loam to clay loam soils 30 to 43 in (76–109 cm) deep (Johnson and Simon 1987). In the Fernow Valley in Utah’s Juab County, shaggy fleabane occurs in the understory of big sagebrush communities, which occupy deep, permeable, salt-free soils with high water–holding capacities (Fautin 1946). In the House Mountain range in Utah, shaggy fleabane is common on gravelly slopes and alluvial flats at moderate elevations (Kass 1988). Shaggy fleabane occurs in sagebrush communities in the mountains of northeastern Nevada where average soil depths range from 8 in (20 cm) in black sagebrush/bluebunch wheatgrass communities to 46 in (117 cm) in mountain big sagebrush/basin wildrye (A. tridentata subsp. vaseyana/Elymus cinereus) communities (Jensen et al. 1988).

Frequency of shaggy fleabane varied more with soil type than grazing influences in an evaluation of salt-desert shrub range near Grand Junction, western Colorado. Frequency of shaggy fleabane was much greater on sandstone (18–22%) and mixed sandstone-shale (21%) soils than on shale soils (0–1%). Frequency differences between grazed and ungrazed sites were 3% or less regardless of soil type. Sites were grazed by domestic sheep and cattle from November to mid-May (Turner 1971). For a broader discussion of shaggy fleabane’s response to grazing, see the Ecology section.

Moisture. Shaggy fleabane generally occurs in communities where soils have low moisture levels. In the Columbia Plateau of eastern Washington, shaggy fleabane was rare along the margins of vernal pools and labeled as flood intolerant (Björk and Dunwiddie 2004). At the base of Pike’s Peak, Colorado, shaggy fleabane is a secondary forb in blue grama (Bouteloua gracilis) grasslands, which occupy coarse gravelly loam soils with 6 to 9% water content (Shantz 1906). Yet in basin big sagebrush vegetation on the Humboldt-Toiyabe National Forest, shaggy fleabane occurred only on wet sites when wet, intermediate, and dry sites were compared. Wet sites were 23 to 98 in (60–250 cm) to the water table. Intermediate sites were 39 to 110 in (100–280 cm) to the water table. Dry sites were 110 to 118 in (280–300 cm) to the water table. Perennial grass and forb cover were higher, and basin big sagebrush cover lower in wet than dry sites (Wright and Chambers 2002).

Description

Shaggy fleabane is a short- to long-lived perennial from a woody taproot and caudex with short, thick branches (Nesom 2006; Welsh et al. 2016). Caudex branches are typically clothed by withered leaf bases (Welsh et al. 2016). Plants are variable, ranging from rather stout to slender, 2 to 20 in (5–50 cm) tall. Stems and leaves are often densely covered with spreading hairs of more than 1 mm long, giving the plant a shaggy or unkempt appearance (Fig. 4) (Taylor 1992; Hitchcock and Cronquist 2018; Luna et al. 2018).

Figure 4. Shaggy fleabane plant with fuzzy stems and leaves growing in Oregon. Photo: BLM OR030, SOS.

Stems are topped with flower heads (Munz and Keck 1973; Hickman 1993; Nesom 2006; Hitchcock and Cronquist 2018). Look alike species include threadleaf fleabane (Erigeron filifolius) and desert yellow fleabane (E. linearis) (Pavek et al. 2012).

Shaggy fleabane produces linear to narrowly oblong basal and stem leaves with smooth margins (Hitchcock and Cronquist 2018; Luna et al. 2018). Leaves are indistinctly petiolate with petioles prominently ciliate with spreading thick-based hairs (Nesom 2006; Luna et al. 2018). Basal leaves are erect, persistent, oblanceolate, and up to 3 in (8 cm) long and 0.2 in (0.5 cm) wide (Hickman 1993; Nesom 2006; Luna et al. 2018). Stem leaves occur on the distal half to three quarters of stems. They are linear-lanceolate and little reduced distally (Nesom 2006).

Individual plants produce up to 50 flat-topped to hemispheric flower heads, which often occur singly at the top of stems (Hickman 1993; Nesom 2006; Pavek et al. 2012; Welsh et al. 2016; Hitchcock and Cronquist 2018). Individual heads have 50 to 150 rays, which are pistillate, fertile, white to pink or lavender, and 6 to 15 mm long (Fig. 5). Ray flowers are thin, reflexed or sometimes weakly coiled, and surround yellow to orange disk flowers. Disk corollas are fertile, 3 to 5 mm tall with distinctly indurate and inflated throats (Nesom 2006; Welsh et al. 2016; Hitchcock and Cronquist 2018). Involucres are hairy, 7 to 15 mm wide, and 4 to 7 mm tall with subequal bracts in two to four series (Nesom 2006; Welsh et al. 2016; Hitchcock and Cronquist 2018; Luna et al. 2018). Bracts are covered with tiny glands, long hairs, and have orange to yellowish or brownish midribs (Nesom 2006; Welsh et al. 2016; Luna et al. 2018).

Figure 5. Small shaggy fleabane flowers. Photo: BLM ID230, SOS.

Shaggy fleabane produces cypsela fruits, hereafter referred to as seeds. Seeds are tiny (1.4–1.8 mm long) with a double pappus. The outer pappus consists of scales or bristles (0.1–0.3 mm long) and the inner pappus of 12 to 27 bristles. Seed bodies are two nerved with sparse, straight, stiff hairs on the seed faces (Nesom 2006).

Variety descriptions. Variety intermedius produces flower heads with usually pink but sometimes white ray flowers and relatively dull, glabrous, or slightly puberulent disk flowers. Variety intermedius seeds have an inner seed pappus of 12 to 20 bristles (Nesom 2006; Hitchcock and Cronquist 2018). Variety pumilus produces flower heads with white ray flowers and shiny, glabrous disk flowers. Variety pumilus produces seeds with inconspicuous outer pappi and inner pappi of 15 to 27 bristles (Nesom 2006; Hitchcock and Cronquist 2018).

Reproduction

Shaggy fleabane reproduces by seed (Fig. 6) (Marlette and Anderson 1986; Pinto et al. 2014). Seeds are generally produced 1 to 2 months after flowers (Pitt and Wikeem 1990). Flower production (abundance and timing) can vary by location and year (Tepedino and Stanton 1980).

Figure 6. Shaggy fleabane seed head. Photo: BLM CP4, SOS.

Phenology

Many sources and studies have reported on shaggy fleabane’s phenology, which includes a flowering range from April to November if plants flower for a second time with fall moisture (Beatley 1976; Pitt and Wikeem 1990; Andersen and Holmgren 1996). In northeastern Utah, shaggy fleabane flowers occur from April to September (Andersen and Holmgren 1996). In central and southern Nevada, flowers are common from April to May at lower elevations and June to July at upper elevations (Beatley 1976).

After 4 years of observations near Sidney, Montana (2,182 ft [665 m]), the average flowering date or time when 10% of plants had at least one flower was June 14 (White 1979). The earliest flowering date was June 7, and the latest flowering date was June 19. In this study, the accumulation of thermal days accounted for 49% of the variation in flowering for early flowering species such as shaggy fleabane (White 1979). In two years of observations (1978–79) made near Penticton, British Columbia, shaggy fleabane began to grow from March to May (Pitt and Wikeem 1990). Flowering began in April or May, and plants were in full flower in May or June. Shaggy fleabane set and shattered seed in July and August. Fall regrowth began in September or October, and plants flowered again in October or November and were cured by December. Phenology observations likely represent ‘normal’ since annual precipitation and growing degree days were similar to the 30-year average (Pitt and Wikeem 1990).

At two shortgrass prairie sites in Wyoming’s Laramie Basin, flower production varied by site and year (Tepedino and Stanton 1980). Shaggy fleabane produced 1.1 flower heads/ft² (12/m²) at one site and 5.5/ft² (59/m²) at the other site in 1975 when permanent quadrats were monitored from late May to late August. No flowers were produced in 1976. Precipitation was much heavier than normal in the spring and early summer of 1975 and was 32% below normal by the end of June in 1976 (Tepedino and Stanton 1980).

Pollination

Shaggy fleabane flowers are insect pollinated. At the Nevada Test Site, carder bees (Anthidium dammersi), fairy bees (Perdita fallugiae), and sweat bees (Lasioglossum sisymbrium) were collected from shaggy fleabane flowers (Allred 1969). In surveys conducted in June of1969 and 1970 in Chaffee County, Colorado, 13 recorded simius roadside skipper butterflies (Amblyscirtes simius) visits were to shaggy fleabane flowers in low hills with sparse cover of pinyon pine and juniper (Scott 1973).

Ecology

Shaggy fleabane is a disturbance tolerant, short- to long-lived perennial that persists in open canopy forests (Daubenmire 1975; Akinsoji 1988; Ross and Wikeem 2002; Carr and Krueger 2012; Welsh et al. 2016). Several studies report greater shaggy fleabane abundance in disturbed than undisturbed plots (McLean et al. 1971; Ross and Wikeem 2002; Metlen et al. 2006).

Seed And Seedling Ecology

The emergence of shaggy fleabane seedlings was greater in native than nonnative-dominated vegetation and greater in unburned than burned plots in the studies described in more detail below.

Shaggy fleabane emerged from soil collected from native vegetation but not from adjacent crested wheatgrass (Agropyron cristatum) and desert wheatgrass (A. desertorum) vegetation at the Idaho National Laboratory in southeastern Idaho (Marlette and Anderson 1986). Shaggy fleabane made up 0.74% of the relative number of seedlings emerging from soil collected in big sagebrush-dominated vegetation, where it makes up 0.66% of relative cover in the aboveground vegetation. Shaggy fleabane did not emerge from soils collected from crested wheatgrass-dominated stands, even though the sampling design was designed to capture seed dispersal between native and nonnative vegetation (Marlette and Anderson 1986).

In a study evaluating the effects of disturbance, water table level, and microhabitat on seedbanks in basin big sagebrush communities, more shaggy fleabane seeds occurred on unburned than burned sites and on wet than dry sites (Table 1; Wehking 2002). The study location on the Humboldt-Toiyabe National Forest, Nevada, included wet sites with a water table at 59 to 95 in (151-242 cm) below the soil surface, and dry sites with a water table more than 118 in (300 cm) below the soil surface. A portion of dry and wet sites were burned in October 1996, and seedbanks were evaluated 1 year following the fire and prior to reseeding and 2 years following fire and 1 year after seeding with native grasses and forbs (9 PLS/ft² [100 PLS/m²]). The seed mix did not include shaggy fleabane. Soil was collected from beneath shrubs and in the shrub interspaces at three depths (litter + 0.4 in [1 cm], 0.4-2 in [1-5 cm], 2-6 in [5-15 cm]). Seedbank composition was determined using the emergence method. Soils were spread over sand and emergence monitored in a greenhouse (86 °F [30 °C] day; 37 °F [3 °C] at night). Although shaggy fleabane did not occur on dry plots, seedlings did emerge from soil collected from dry plots. Seeds of shaggy fleabane persisted after burning in the upper soil at the wet site. Rarely did shaggy fleabane emerge from soils collected deeper than 2 in [5 cm]. Seeds were more abundant in the interspaces than beneath shrubs on burned plots and the reverse was true for unburned plots (Wehking 2002).

Table 1. Emergence of shaggy fleabane seed by water table level (Wet: water table 59-95 in. below soil surface; Dry: water table >118 in. below soil surface), disturbance, microhabitat, and soil depth from seedbanks collected from basin big sagebrush communities on the Humboldt-Toiyabe National Forest in central Nevada (Wehking 2002).

Depth (in)	Wet				Dry
	Burned		Unburned		Burned		Unburned
	Undershrub	Interspace	Undershrub	Interspace	Undershrub	Interspace	Undershrub	Interspace
	Number of seeds/m²
litter + 0.4	0	128	256	62	0	6	102	28
0.4-2	6	51	165	63	18	42	316	110
2-6	0	0	28	0	0	0	0	0

*Seed distribution in the soil profile only evaluated for year 1997 and on burned sites in 1998.

Disturbance Ecology

Shaggy fleabane is commonly found on cattle–grazed sites but may be less tolerant of sheep and big game grazing. In ponderosa pine-Idaho fescue communities in the Similkameen Valley of southern British Columbia, shaggy fleabane abundance increased with heavy cattle grazing when opposite sides of a fence line were compared (McLean et al. 1971). On winter range in the Rocky Mountain trench north of Cranbrook, British Columbia, an exclosure was constructed in 1951 to evaluate the impacts of large ungulate grazing (Ross and Wikeem 2002). Cattle grazing was heavy in spring and fall before construction of the exclosure, but by 1950, grazing management was altered to a lower stocking rate and later spring turnout. Shaggy fleabane was greater on grazed than ungrazed plots for the 34-year comparison of vegetation inside and outside of the exclosure that protected vegetation from cattle, deer, and elk grazing (Table 2; Ross and Wikeem 2002).

Table 2. Cover (C) and frequency (F) of shaggy fleabane in grazed and ungrazed plots over time at a site north of Cranbrook, British Columbia (Ross and Wikeem 2002).

Treatment	1960		1970		1982		1991		1994
	C (%)	F (%)	C	F	C	F	C	F	C	F
Exclosure	0.7	8	0	0	0.2	6	0	0	0	0
Grazed	1.2	30	4	54	4	90	0.2	8	1.9	24

At the Idaho National Laboratory site near Idaho Falls, shaggy fleabane cover was 0.3% and frequency was 11% in ungrazed sagebrush, but plants did not occur in grazed sagebrush or grazed or ungrazed crested wheatgrass stands. The grazed area (540 mi² [1,390 km²])supported 1,000 to 2,000 domestic sheep each spring, and the ungrazed plots were free of livestock for 25 years (Reynolds and Trost 1981). Krueger and Winward (1974) evaluated the effects of cattle and big game grazing after 14 years of protection at the Eastern Oregon Experiment Station. Shaggy fleabane frequency was 14% on plots grazed by both cattle and big game, 0% on plots grazed by big game only, and 0% on ungrazed plots. The study area was livestock grazed for more than 100 years before treatments in the Douglas-fir (Pseudotsuga menziesii)-ponderosa pine/Kentucky bluegrass (Poa pratensis) study area.

Abundance of shaggy fleabane was consistently greater on burned than unburned plots in available fire studies. In threetip sagebrush and basin big sagebrush shrublands in Power County, Idaho, shaggy fleabane cover averaged 0.24% on 1-year-old burned plots and 0.09% on unburned plots. Shaggy fleabane did not emerge from 10 soil cores collected from burned and unburned plots (Akinsoji 1988). Frequency of shaggy fleabane was much greater on burned (65%) than unburned plots (18%) 2 years following fire in bluebunch wheatgrass-Sandberg bluegrass communities in southeastern Washington. Four years following fire, frequency was greater on unburned (15%) than burned plots (2%), and by the twelfth post-fire year, there was no difference in frequency between burned and unburned sites (Daubenmire 1975). The frequency of shaggy fleabane was greater after than before burning, thinning, or combined treatments in ponderosa pine-Douglas-fir forests at the Lubrecht Experimental Forest in Missoula County, Montana. Post-treatment monitoring occurred 3 years following thinning and 2 years following burning. Burning of all plots occurred in the spring, and fires were of low to moderate severity (Table 3; Metlen et al. 2006).

Table 3. Frequency of shaggy fleabane on treated and untreated plots in ponderosa pine-Douglas-fir forests at the Lubrecht Experimental Forest in Missoula County, Montana (Metlen et al. 2006).

Treatment	Control	Burn only	Thin only	Thin + burn
	Frequency (%)
Pretreatment	20	3	7	13
3 yrs after thin; 2 yrs after burn	30	27	23	33

Successional status. Shaggy fleabane occurs in early and late seral communities. In southeastern Washington, shaggy fleabane occurred in newly abandoned old fields (1, 2, and 5 years since last cultivation). It also occurred in older fields cultivated 39 to 52 years ago and in undisturbed rangeland vegetation. Cover of shaggy fleabane was low in both old fields and undisturbed vegetation (Daubenmire 1975).

In eastern Oregon’s Malheur National Forest, shaggy fleabane occurred in the understory of ponderosa pine woodlands that averaged 275 pine stems/ac (679/ha) and 57% canopy cover but not in the understory of denser stands averaging 1,312 pine stems/ac (3,244/ha) and 79% canopy cover (Carr and Krueger 2012).

Wildlife And Livestock Use

Available literature indicates that shaggy fleabane is eaten by pronghorn (Antilocarpa americana), domestic sheep, various small mammals, and greater sage-grouse (Centrocercus urophasianus). In semi–desert vegetation in western Utah, shaggy fleabane received moderate pronghorn use whenever available. Use was greater in spring and wet summers than in dry summers (Beale and Smith 1970). On the Desert Experimental Range and Awapa Plateau in Utah, maximum pronghorn use of shaggy fleabane was 2% in the spring as determined by feces and rumen analysis (Smith and Beale 1980). Pronghorn fed on shaggy fleabane in the summer in central Montana (Cole 1956; Wentland 1968). Shaggy fleabane made up 17% of the forb feeding observations made on 62 feeding sites monitored in June 1966 and a trace of observations in June 1967 (Wentland 1968). Shaggy fleabane was not used by pronghorn in July or August.

A study near Missoula, Montana, evaluated whether domestic sheep could control invasive forbs without compromising native plant restoration efforts (Masin et al. 2018). Shaggy fleabane was grazed less than 1% at the study site where its frequency was 7%. The grazing study was conducted in bluebunch wheatgrass-Sandberg bluegrass communities with a mix of native and nonnative forb species. Sheep grazed plots heavily invaded by leafy spurge for 3 weeks before grazing the study area (Masin et al. 2018).

Small mammal use of shaggy fleabane was reported in studies conducted in Washington (Richardson et al. 2013) and Idaho (Dyni and Yensen 1996). A single pocket mouse (Perognathus parvus) captured from native shrub steppe vegetation in the northern Columbia Basin of eastern Washington had 17 shaggy fleabane seeds in its cheek pouch. Pocket mice were trapped in fall 2003 and 2004 and the single capture with shaggy fleabane seeds represented just 0.1% of mice captured and 0.1% of total seeds recovered. Grass seeds, especially cheatgrass (Bromus tectorum), were collected most by pocket mice (Richardson et al. 2013). In Adams County, Idaho, Columbian and Idaho ground squirrels fed on shaggy fleabane stems and leaves. Diets of Columbian ground squirrels were 0.6% shaggy fleabane in mixed–conifer forests in early July and 0.9% in meadows in early June. Idaho ground squirrel diets were 1.2% shaggy fleabane in meadow vegetation in early June (Dyni and Yensen 1996).

Shaggy fleabane flowers are eaten by greater sage-grouse (Luna et al. 2018), and it is an important component of brood–rearing (Wik 2002) and mating habitats (Petersen 1980). Shaggy fleabane is also utilized by a variety of insects and invertebrates that are eaten by greater sage-grouse (Luna et al. 2018). In south-central Owyhee County, Idaho, shaggy fleabane grows in big sagebrush habitats used as brood-rearing habitat by greater sage-grouse (Wik 2002). In the Spring Creek area of North Park, Colorado, shaggy fleabane occurred on two of three greater sage-grouse mating sites in sagebrush vegetation. Cover of shaggy fleabane was low (0.1– 0.3% cover) in the mating area where sagebrush cover averaged 7.3% and sagebrush height averaged 2 in (5.3 cm) (Petersen 1980).

For information on the use of shaggy fleabane by insects, see the Pollination section.

Ethnobotany

Indigenous peoples had a variety of uses for shaggy fleabane. The Okanaga-Colville used an infusion of shaggy fleabane roots as an eye tonic or wash (Turner et al. 1980, cited in Moerman 2003). The Lakota used a decoction of shaggy fleabane to treat rheumatism, lameness, and stomach issues (Munson 1981).

Horticulture

Attractive flowers, pollinator use, and tolerance of drought and early seral conditions make shaggy fleabane a useful native plant for landscaping or use in roadside, campground, or other low-maintenance plantings (Meyer et al. 2009; Tilley et al. 2013). Because shaggy fleabane attracts predatory and parasitoid insects (LBJWC 2015), it could be useful in organic gardening or crop production.

Revegetation Use

Shaggy fleabane is recommended for revegetation of sites receiving 6 to 17 in (152–432 mm) of annual precipitation. The species has a rapid growth rate and is attractive to bee and butterfly pollinators (Tilley et al. 2013).

Developing A Seed Supply

For restoration to be successful, the right seed needs to be planted in the right place at the right time. Coordinated planning and cooperation is required among partners to first select appropriate species and seed sources and then properly collect, grow, certify, clean, store, and distribute seed for restoration (PCA 2015).

Developing a seed supply begins with seed collection from native stands. Collection sites are determined by current or projected revegetation requirements and goals. Production of nursery stock requires less seed than large-scale seeding operations, which may require establishment of agricultural seed production fields. Regardless of the size and complexity of any revegetation effort, seed certification is essential for tracking seed origin from collection through use (UCIA 2015).

Seed Sourcing

Because empirical seed zones are not currently available for shaggy fleabane, generalized provisional seed zones developed by Bower et al. (2014), may be used to select and deploy seed sources. These provisional seed zones identify areas of climatic similarity with comparable winter minimum temperature and aridity (annual heat:moisture index). In Figure 7, Omernik Level III Ecoregions (Omernik 1987) overlay the provisional seeds zones to identify climatically similar but ecologically different areas. For site-specific disturbance regimes and restoration objectives, seed collection locations within a seed zone and ecoregion may be further limited by elevation, soil type, or other factors.

The Western Wildland Environmental Threat Assessment Center’s (USFS WWETAC 2017) Threat and Resource Mapping (TRM) Seed Zone application provides links to interactive mapping features useful for seed collection and deployment planning. The Climate Smart Restoration Tool (Richardson et al. 2019) can also guide revegetation planning, seed collection, and seed deployment, particularly when addressing climate change considerations.

Occurrence Map

Figure 7. Distribution of shaggy fleabane (black circles) based on geo-referenced herbarium specimens and observational data from 1881-2016 (CPNWH 2020; SEINet 2020; USDI USGS 2020). Generalized provisional seed zones (colored regions) (Bower et al. 2014) are overlain by Omernik Level III Ecoregions (black outlines) (Omernik 1987; USDI EPA 2018). Interactive maps, legends, and a mobile app are available (USFS WWETAC 2017; www.fs.fed.us/wwetac/threat-map/TRMSeedZoneMapper2.php?). Map prepared by M. Fisk, USDI USGS.

Releases

As of 2021, there are no known shaggy fleabane germplasm releases.

Wildland Seed Collection

Indeterminate flowering (Fig. 8) makes monitoring and revisiting sites necessary when making shaggy fleabane seed harvests. Wildland seed collections are typically made by hand (Camp and Sanderson 2007; DeBolt 2016; USDI BLM SOS 2017).

Wildland Seed Certification

Verification of species and tracking of geographic source is necessary whether wildland seed is collected for immediate project use or as stock seed for cultivated increase. This official Source Identification process can be accomplished by following procedures established by the Association of Official Seed Certifying Agencies (AOSCA) Pre-Variety Germplasm Program (Young et al. 2020; UCIA 2015). Wildland seed collectors should become acquainted with state certification agency procedures, regulations, and deadlines in the states where they collect.

If wildland-collected seed is to be sold for direct use in ecological restoration projects, collectors must apply for Source-Identified certification prior to making collections. Pre-collection applications, site inspections, and species and seed amount verification are handled by the AOSCA member state agency where seed collections will be made (see listings at AOSCA.org).

If wildland seed collected by a grower or private collector is to be used as stock seed for planting cultivated seed fields or for nursery propagation (See Agricultural Seed Field Certification section), detailed information regarding collection site and collecting procedures must be provided when applying for certification. Photos and herbarium specimens may be required. Germplasm accessions acquired within established protocols of recognized public agencies, however, are normally eligible to enter the certification process as stock seed without routine certification agency site inspections. For contract grow-outs, however, this collection site information must be provided to the grower to enable certification.

Figure 8. Shaggy fleabane plant growing in Idaho. This plant has flowering stems with mature seed, drying flowers, and fresh flowers. Photo: BLM ID120, SOS.

Collection Timing

Mature shaggy fleabane seeds are small, light-colored, and easily detached from the seed head (Camp and Sanderson 2007; DeBolt 2016). Wildland seed collections are time consuming and often require multiple site visits since seed production is indeterminate. Harvests should begin as soon as seed heads begin to ripen because seed shatters rapidly and falls readily from seed heads when disturbed (Camp and Sanderson 2007). Seeds are typically harvested from mid-May to late July (Camp and Sanderson 2007; USDI BLM SOS 2017). The Bureau of Land Management (BLM) collected shaggy fleabane seed from late June to late July at 1,900-ft (580 m) sites in Douglas County, Washington (Camp and Sanderson 2007). The BLM’s Seeds of Success crews made 30 shaggy fleabane seed harvests in 12 years from 2002 to 2016 in Washington, Oregon, Nevada, Idaho, Utah, and Colorado. The earliest collection was made on May 21, 2015 at 4,789 ft (1,460 m) in Uintah County, Utah. The latest collection was made on July 27, 2011 at 3,925 ft (1,196 m) in Malheur County, Oregon. Most collection sites had a lot of seed already on the ground (USDI BLM SOS 2017).

Collection Methods

Wildland seeds (Fig. 9) can be collected by shaking or knocking seed heads into a container or by picking mature seeds from the seed heads (Camp and Sanderson 2007; DeBolt 2016; USDI BLM SOS 2017).

Figure 9. Collection of about 40 freshly collected seeds from shaggy fleabane plants in Idaho. Photo: BLM ID230, SOS.

Several collection guidelines and methods should be followed to maximize the genetic diversity of wildland collections: 1) collect seed from a minimum of 50 randomly selected plants; 2) collect from widely separated individuals throughout a population without favoring the most robust or avoiding small stature plants; and 3) collect from all microsites including habitat edges (Basey et al. 2015). General collecting recommendations and guidelines are provided in online manuals (e.g., ENSCONET 2009; USDI BLM SOS 2021).
It is critical that wildland seed collection does not impact the sustainability of native plant populations. Collectors should take no more than 20% of the viable seed available at the time of harvest (USDI BLM SOS 2021). Additionally, care must be taken to avoid the inadvertent collection of weedy species, particularly those that produce seeds similar in shape and size to those of shaggy fleabane.

Post-Collection Management

Small wildland seed collections were air dried in paper bags at room temperature for 2 to 4 weeks before cleaning (Camp and Sanderson 2007; DeBolt 2016). DeBolt (2016) added a 1-in² (6 cm²) piece of no-pest strip in the bag for 3 days to minimize insect predation.

Seed Cleaning

Several mechanical cleaning methods have been described. The Bridger, Montana, Plant Materials Center (PMC) cleaned small quantities of fleabane seed using a blender with duct tape-wrapped blades. Blenders were filled up to 33% and pulsed at low speed. Blending was followed by sieving and winnowing over a small fanning mill (Scianna 2004). The USFS Bend Seed Extractory cleaned small seed lots (Fig. 10) using a small brush machine (mantle #32, speed 1, and medium bristle brushes) followed by hand sieving with a #40 USGS screen and then processing with an office clipper (DeBolt 2016).

Figure 10. Shaggy fleabane seeds under magnification. Seeds were cleaned and the photo provided by USFS Bend Seed Extractory.

Seed Storage

Shaggy fleabane seed is orthodox. Viability was 93% for seed dried to equilibrium with 15% relative humidity and stored for 1 month at 68 °F (20 °C) (Kew 2017). Other researchers reported storing seed in glass jars at 40 °F (4 °C) and 35% relative humidity (Camp and Sanderson 2007) or in cool, dry, and dark locations (DeBolt 2016).

Seed Testing

There is general guidance for testing the viability and germination of fleabane species (Moore 1985).

Viability Testing

Seed viability testing requires seeds be kept moist for 6 to 18 hours before cutting. Seeds are cut longitudinally through the mid-section of the distal half without cutting the embryonic axis at the basal end. The distal end of the seed including the tips or edges of the cotyledons is removed before staining for 6 to 24 hours. Seeds that stain completely or completely except for the distal third of the radicle are viable (Moore 1985).

Germination Biology

Although germination testing rules were not available for shaggy fleabane, there is an AOSA rule for aspen fleabane (Erigeron speciosus), which says to keep seed moist, in the light at 59 °F (15 °C). First germination counts should be made at 6 days and last counts at 16 days (AOSA 2016).

Wildland Seed Yield And Quality

Post-cleaning seed yield and quality of seed lots collected in the Intermountain region are provided in Table 5 (USFS BSE 2017). Results indicate that shaggy fleabane seed is tiny and that the purity and viability of fresh seed are highly variable. Other seed/lb values reported in the literature (1,300,000–1,800,000 seeds/lb [2,866,000–3,968,000 seeds/kg]) fall below those reported in Table 5 (Lambert 2005; Camp and Sanderson 2007).

Table 5. Seed yield and quality of shaggy fleabane seed lots collected in the Intermountain region, cleaned by the Bend Seed Extractory, and tested by the Oregon State Seed Laboratory or the USFS National Seed Laboratory (USFS BSE 2017).

Seed lot characteristic	Mean	Range	Samples (no.)
Bulk weight (lbs)	0.32	0.03–1.2	37
Clean weight (lbs)	0.04	0.002–0.18	37
Clean–out ratio	0.13	0.02–0.27	37
Purity (%)	88	40–99	37
Fill (%)¹	95	80–99	37
Viability (%)²	88	52–97	27
Seeds/lb	5,014,110	2,362,500–13,341,176	37
Pure live seeds/lb	3,952,142	6,396,671–1,988,412	27

¹ 100 seed X–ray test
² Tetrazolium chloride test

Marketing Standards

Acceptable seed purity, viability, and germination specifications vary with revegetation plans. Purity needs are highest for precision seeding equipment used in nurseries, while some rangeland seeding equipment handles less clean seed quite well.

Agricultural Seed Production

Growth of shaggy fleabane in an agricultural setting for seed production was not reported in the literature. Reports suggest that shaggy fleabane germinates and establishes well and grows rapidly (Pavek et al. 2013; Tilley et al. 2013), although rapid growth in not guaranteed (Pavek et al. 2013). Seed should not be planted any deeper than 0.25 in (0.6 cm) (Pavek et al. 2013; Ogle et al. 2014). Because shaggy fleabane is insect pollinated, any growing and management practices that encourage native pollinator populations should be helpful to seed production. Indeterminate seed set will require multiple hand harvests or other ingenious collecting techniques. See the Agricultural Seed Production section of the aspen fleabane chapter for potentially useful guidance on growing shaggy fleabane seed fields.

Agricultural Seed Certification

In order to minimize genetic changes in specific accessions of native species when increased in cultivated fields, it is essential to track the geographic source and prevent inadvertent hybridization or selection pressure. This is accomplished by following third party seed certification protocols for Pre-Variety Germplasm (PVG) as established by the Association of Official Seed Certification Agencies (AOSCA). AOSCA members in the U.S., Canada, and other countries administer PVG requirements and standards that track the source and generation of planting stock. Field and cleaning facility inspections then monitor stand establishment, proper isolation distances, control of prohibited weeds, seed harvesting, cleaning, sampling, testing, and labeling for commercial sales (Young et al. 2020; UCIA 2015).

Seed growers apply for certification of their production fields prior to planting and plant only certified stock seed of an allowed generation (usually less than four). The systematic and sequential tracking through the certification process requires preplanning, knowing state regulations and deadlines, and is most smoothly navigated by working closely with state certification agency personnel. See the Wildland Seed Certification section for more information on stock seed sourcing.

Nursery Practice

Shaggy fleabane nursery stock was grown successfully using the following protocols:

1) Methow Natives in Winthrop, Washington, seeded shaggy fleabane in flats filled with a 1:1:1 peat moss, perlite, and vermiculite mix, which was amended in 24 ft³ (0.7 m³) batches with 5 lbs (2 kg) dolomite lime, 7 lbs (3 kg) Osmocote fertilizer (NPK 18-6-12), half a cup of super phosphate, and 1 lb (0.5 kg) of micronutrient fertilizer. Flats were stratified outdoors for 4 months from November to March then brought into the greenhouse. Germination was good in the greenhouse and seedlings were transplanted into 10-in³ (0.2 m³) cones in the summer and outplanted in the fall. Overall, shaggy fleabane grew well under nursery conditions (Camp and Sanderson 2007).

2) DeBolt (2016) sowed 3 to 10 shaggy fleabane seeds into containers (2.75 × 5.5-in [7 x 14–cm]) filled with a 2:1:5 mix of lava fines, perlite, and Sunshine mix #4. Seeds were pressed lightly into the mix to about 0.125 to 0.2-in (0.3–0.6 cm) depths and covered with thin layer of chicken grit. Containers were hand watered and put outdoors in mid-March and late April. By early July, the germination rate was about 90%. Containers dried slightly between waterings, and a weak fish emulsion fertilizer was applied twice each month from April through June. Containers were moved to an outdoor shade house from July through September and outplanted in October. All flower stalks were removed as they appeared. Plants had healthy root development that filled the containers within 6 to 7 months of sowing seed outdoors in spring (DeBolt 2016).

Fungi (Entyloma compositarum, Phyllactinia guttata, Puccinia stipae, Ramularia macrospora, and Septoria erigerontis) were collected from shaggy fleabane plants growing in Oregon, Washington, Idaho, and Montana (Farr and Rossman 2017). These fungi were not reported as issues in nursery operations.

Wildland Seeding And Planting

Shaggy fleabane provides pollinator habitat in the revegetation and restoration of adapted sites with medium to coarse-textured soils receiving 6 to 17 in (152–432 mm) of annual precipitation (Pavek et al. 2013; Ogle et al. 2014; Tilley et al. 2019). The recommended seeding rates range from 1 to 4 lbs/ac (1–4 kg/ha) for pure stands (Ogle et al. 2011; Tilley et al. 2013), but it is not recommended for use in pure stands (Ogle et al. 2014). Recommended seeding depths are 0.125 to 0.25 in (0.3–0.6 cm) (Ogle et al. 2014).

Camp and Sanderson (2007) reported good establishment in one of two years of seeding in small plots in the Columbia Basin. Ten to twenty seeds were planted per plot in fall 2004 and again in fall 2005. Twenty percent of the 2004 plots had at least one plant in the following spring and 5% in the second spring. Ninety percent of the 2005 plots had at least one plant establish in the following spring (Camp and Sanderson 2007).

Irrigation (Camp and Sanderson 2007) and protection from herbivory (DeBolt 2016) can increase survival of shaggy fleabane plantings. Second season survival was greater when shaggy fleabane seedlings were irrigated than when not irrigated in the Columbia Basin. Seedlings were planted in fall 2004 (40 plants/treatment) and fall 2005 (50 plants/treatment). For the fall 2004 planting, 75% of irrigated and 65% of non-irrigated plants survived to the following spring and 18% of irrigated and 8% of non–irrigated plants survived to the second spring. For the fall 2005 planting, 50% of irrigated and 32% of non-irrigated plants survived to the following spring (Camp and Sanderson 2007). When nursery–grown shaggy fleabane plants (2.75 × 5.5-in [7 × 14-cm] containers) were outplanted to rangeland sites in October, protection from herbivory substantially improved survival. Plants were watered at least once after planting (DeBolt 2016).

Additional field studies in establishing and managing plantings that include shaggy fleabane may provide some insight to ways to encourage establishment or manage revegetated sites. In semi–arid rough fescue and Idaho fescue–dominated grasslands in western Montana’s Blackfoot River drainage, shaggy fleabane established significantly (P < 0.05) better on disturbed than on undisturbed plots (Maron et al. 2012). Field experiments evaluated rodent exclusion and disturbances on recruitment by adding 175 seeds to 1.5 × 1.5-ft (0.5 × 0.5-m) subplots. There were 0.2 or fewer shaggy fleabane seedlings in undisturbed, vegetated subplots and 0.7 seedlings in disturbed plots with and without rodent exclusion. Shaggy fleabane seed used in the experiments was collected from nearby. Subplot disturbances had all competitive vegetation removed and the top 4 in (10 cm) of soil disturbed (Maron et al. 2012).

In field experiments conducted in mixed-grass prairie at the High Plains Grassland Research Station near Cheyenne, Wyoming, shaggy fleabane showed a cumulative negative response to nitrogen fertilization (Samuel and Hart 1998). The treatments applied nitrogen at rates of 20 to 30 lbs/ac (22–34 kg/ha) in late October or early March from fall 1974 through spring 1981. As the treatments began, there were several years where the frequency of shaggy fleabane was not significantly different on fertilized and control plots, but from 1983 to 1988, frequency was significantly (P < 0.05) greater on controls than any nitrogen–treated plots. Researchers noted that the effects could have been the result of fertilization itself or responses of associated vegetation and that effects of nitrogen fertilization on shaggy fleabane alone are unknown (Samuel and Hart 1998).

In rough fescue and Idaho fescue grasslands near Missoula in west–central Montana, shaggy fleabane typically recovered within 2 to 3 years of broadcast herbicide treatments targeting spotted knapweed (Centaurea stoebe subsp. micranthos). Picloram, clopyralid, and clopyralid + 2,4–D were applied at the recommended rates to control spotted knapweed. Herbicides were applied early when spotted knapweed was in the rosette to early bolt stage or applied late at the early to mid-flower stage (Rice and Christopher 1998).