The Nature Conservancy

Midwest Regional Office

13i3 Fifth Street S.E., Minneapolis, Minnesota 55414

(612) 379-2207


Element Stewardship Abstract (ESA)


Cirsium Pitcheri



Prepared for

Eastern Region, Forest Service, USDA





Headquarters Office, 1815 North Lynn Street, Arlington, Virginia 22209




  • >== 0012 STEW-ABS-RESP

  • MRO



    1313 5TH STREET SE, BOX 78



  • >== 0016 PREPARER

  • WAYNE OSTLIE (1990)
  • >== 0020 NAME

  • >== 0050 COMMON NAME






  • >== 0100 DESCRIPTION

  • Cirsium pitcheri was formally listed by the USFWS as a threatened species on July 18, 1988 (USFWS 1988a, 1988b). Moore and Frankton (1974) botanically described Cirsium pitcheri as follows:
  • "Biennial herb with a long taproot. Plant to 8 dm high. S tem slender and rather woody, ribbed gray tomentose, short-branched at the summit and bearing 1-5 heads. Cauline leaves td 2 dm long, basal leaves to 3 dm, all leaves deeply Pinnately segmented to the midrib into linear or narrowly oblong divisions, tipped by a minute spine. Leaves flexible, green above, gray below, with dense tomentum of long, wavy hairs composed of a long apical cell and several short basal cells. Heads 3.5-5 cm high, involucre 2-3 cm high, composed of about 6 rows of dark-colored phyllaries, progressively longer from outer to inner rows. Outer phyllaries about 3 mm broad, ovate-lanceolate, terminal spine 23 mm; strongly glandular, with sparse arachnoid marginal pubescence. Innermost phyllaries unarmed, the tips tapering, twisted. Flowers white or pinkish white. Corollas 20-30 mm long; tube 8.5-15 mm, throat 4.5-10 mm, lobes 3-8 mm; pappus about 1 mm shorter than the corolla, composed of 55-65 tawny setae. Anthers 7.5-8.5 mm long. Pollen tricolporate, polar diam 51-58 micrometers; spines stout. Achenes 6.5-7.5 mm long, 2.5 mm broad, brown or purplish brown, with a very narrow (042 mm) lighter apical rim, surface of achene mucilaginous when wet."
  • Mickelson and Iltis (1963) described the Cirsium pitcheri as:

  • "A beautiful and distinctive thistle..... Densely white-woolly and deeply divided leaves with long petioles, cream colored or yellowish flowers in heads borne singly or few together on numerous stem branches to 80 cm tall from leafy basil axils, all characterize this species. The species is a biennial,, forming a very handsome rosette flattened against the dune sands the first year, to grow into a blooming plant the next year,, only to die. Taproots sometimes develop to over 2 m in length, adaptive to the pure dry sand of the dune habitat."
  • More recently, the species has been discovered to be a monocarpic perennial, existing up to 8 years as a rosette before reaching a minimum rosette size for flowering (McEachern et al. 1989, Dauberpool and Gibson 1987, Keddy and Keddy 1984, Keddy 1981).

    Seedlings can be distinguished by a pair of paddle-shaped, pale green ,cotyledons (Keddy 1981). The first pair of true leaves that are produced are linear, white-hairy and spine-tipped.

    >== 1000 HABITAT

    Cirsium pitcheri occurs most prominently in Michigan, occurring in 18 counties along the shorelines of Lakes Michigan, Huron and Superior (Nepstad1981). In Wisconsin, the species currently exists in eight sites in four counties on the Lake Superior shoreline (Alverson 1981). The species occurs at seven extant sites along Lake Michigan in Indiana (IN NHP 1989), but has been extirpated from Illinois (Sidle 1987, White 1981). It is also known from roughly 12 extant sites in Ontario, including a population on the shoreline of Lake Su erior (Keddy and Keddy 1984, Keddy 1988).


    Pitcher's thistle is a regional endemic restricted to the dune habitats in the western Great Lakes region (USFWS 1987, Dobberpuhl and Gibson 1987, Keddy and Keddy 1984, Loveless 1983, Guire and Voss 1963). The species is a colonizer on open dune ridges, dune blowouts, and along disturbed sites in sand dunes, but is found on stabilized grassy sand terraces, sandy gravel flats and dune valleys as well (Loveless 1983). In all habitat types, however, the species appears to establish itself only in very open, sandy soil (Loveless 1983).

    McEachern et al. (1989) described the habitats associated with the lakeshores as: 1) extremely exposed open communities on lake level foreduhes and dune bluff edges dominated by Ammophila breviligulata, 2) transitional communities dominated by three dune grasses, A. breviligulata, CalamovilfA longifolia and Schizachyrium scoparium, and 3) stabilized inland blowouts characterized by S. scoparium/C. longifolia codominance and moderate vegetation and litter accumulation. These three habitat types mark a successional gradient, in which A. breviligulata, adapted to high rates of sand deposition occurring in the shoreline habitats, is replaced by the more competitive C. longifolia and finally, S. scoparium in progressively stable inland areas (McEachern et al. 1989) . Associated with this change in dominant vegetation along a shoreline to, inland transect, there is an equally signif icant reduction in the percentage of bare ground. This amount of bare ground is apparently signif icant, for it is in the most stable, S. scoparium dominated areas that C. pitcheri is the least abundant (McEachern et al. 1989).

    In Michigan, C. pitcheri is most common along the northern and northeastern shore of Lake Michigan, although small populations are known from the southeastern shores of Lake Michigan and northern Lake Huron (Crispin and Penskar 1990). A few populations also occur along Lake Superior. cirsium pitcheri typically grows in association with Ammophila breviligulata,Schizachyrium scoparium, Arabis lyrata, Arctostaphylos uva-ursi, Calamovilfa longifolia and Agropyron dasystachyum (Crispin and Penskar 1990, MI NFI 1990). At disturbed sites, Asclepias syriaca may be present (Crispin and Penskar 1990).

    At Sleeping Bear Dunes National Lakeshore in Michigan, the species is apparently doing well, even in the intensely utilized areas around the marina (Hazlett and van de Kopple 1983). A recent survey by McEachern et al. (1989) found that C. pitcheri was occupying much of its potential habitat: foredunes, blowouts, dune ridges, valleys and slopes. Although C. pitcheri was least common from the backslopes of inland dunes, localized populations were found there as well.

    On the Manitou Islands portion of Sleeping Bear Lakeshore, plants have been found on perched (260 feet above Lake Michigan, , on glacial moraines) and coastal dunes. McEachern et al. (1989) found that plants growing on the dunes of South Manitou Island appeared more stunted and were more dispersed than those on the mainland, possibly reflecting the harsher environment of the island. Associates on a gravel lag behind a coastal dune comp lex at Dimmick's Point on North Manitou Island include. Agropyron dasystachyum, Sdhizachyrium scoparium, Anemone multifida, Artemesia caudata, Betula@ papyrifera, Campanula rotundifolia, Carex garberi, Thuja occidentalis and Zygadenus glaucus with an overstory of Betula papyrifera. Associates in a dune blowout on South Manitou include Schizachyrium scoparium, Anemone multifida, Arctostaphylos uva-ursi, Arenaria stricta, Aster sp., Calamovilfa longifolia, Coreopsis palmata, Equisetum hyemale, Ostrya virginiana, Polygonatum pubescens, Prunus virginiana, Trientalis borealis, Trillium grandiflorum,, Viburnum acerifdlium, Viola canadensis and Viola sp. (Hazlett and van de Kopple 1983). For additional habitat information pertinent to Sleeping Bear National Lakeshore, see McEachern et al. (1989), Hazlett (1986) and Loveless (1983).

    At Grand Sable Dunes within the Pictured Rocks National Lakeshore of Michigan, McEachern et al. (1989) found the populations occupying dune and blowout habitats ranging from the dune bluf f inland to wooded areas. In contrast to Sleeping Bear, populations were scattered and were f ar less abundant. For habitat information concerning populations at Pictured Rocks National Lakeshore, see McEachern et al. (1989).

    Within the state of Indiana, plants have been observed on dunes, foredunes, blowouts and beaches along Lake Michigan (IN NHP 1989). At the Indiana Dunes National Lakeshore, Bowles et al. (1985) found Cirsium pitcheri restricted to early and mid-successional blowouts on the high dunes adjacent to Lake Michigan. It appeared to be absent from the first foredune. Sites were extremely well-drained and support sparse dry sand prairie-like communities (Bowles et al. 1985). A recent survey of the site by McEachern et al. (1989) produced similar conclusions. In all, six small populations were found, all on the steep, lakeward-facing slopes or grassland blowouts of the seconda dunes. No plants were observed on the beach and foredune complexes still rebuilding since the high-water levels of 1986 and 1987.

    Dobberpuhl and Gibson (1987) stated that in Wisconsin, the plant is-found in three habitats: (1) dry sand of partially-stabilized dunes along Lake Michigan, (2) dry, open areas of loose sand (sand blowouts) behind the main foredune and infrequently on (3) low, moist to wet beaches. Colonies thrive best in situations where the dunes are somewhat stabilized, in various slope aspects and degrees of steepness. Two populations in Wisconsin are at the mouths of creeks, where continual sand deposition from the creeks provides new habitat and increasing site longevity (WI NHP 1990, Dobberpuhl and Gibson 1987). Associated plants species in Wisconsin include Agropyron dasystachyum, Calamovilfa longifolia var. magna, Elymus canadensis, Ammophila breviligulata, Agropyron trachycaulon, Artemesia caudata, Lathyrus maritimus, Oenothera parviflora, Potentilla anserina and Solidago gillmani (WI NHP 1990, Alverson 1979, Johnson and Iltis 1963).

    In Canada, C. pitcheri is found only in Ontario on sandy beaches and dunes of the shores of Lake Huron and Georgian Bay (Moore and Frankton 1974) and Lake Superior (Keddy and.Keddy 1984, Keddy 1981). At Lake Superior sites in Pukaskwa National Park, plants grow approximately 1-2 meters above the lake level on gently sloping sand beaches in three distinct habitats: 1) grass (dominated by Ammophila breviligulata and Equisetum variegatum), 2) debris (dominated by Prunus pumila and Festuca saximontana) and 3) shrub (dominated by Juniperus horizontalis and Arctostaphylos uva-ursi) (Keddy and Keddy 1984, Keddy 1981). Most plants (79%) were found in the grass habitat, with 21% growing in the debris habitat. Less than 1% were found in the shrub habitat.


    >== 2000 BIOLOGY-ECOLOGY

    Cirsium pitcheri is closely related to C. canescens, a thistle of the sand hills of the Great Plains (Ownbey and Hsi 1963). Recent electrophoretic evidence has shown that the thistles share the same genetic loci, but differ greatly in the level of genetic diversity (Loveless and Hamrick 1988). Cirsium pitcheri possesses a much reduced level of genetic variability than does C. canescens, suggesting derivative-progenitor relationship, respectively. It is believed that Pitcher's thistle migrated to the Great Lakes region soon after the close of the Wisconsinan glaciation and that ts reduced genetic diversity is a result of repeated and prolonged population bottlenecks (Loveless and Hamrick 1988).

    Seed germination in C. pitcheri has been observed during June in Ontario (Keddy and Keddy 1984, Keddy 1981), Michigan and Indiana (McEachern et al. 1989). Keddy and Keddy (1984) found that the highest seedling mortality typically occurred in sand substrates, with the lowest in substrate of debris. In a season of drought, Ziemer (pers. comm.) still found seedling survivorship in the species to be fairly high (roughly 40%). Seedling survivorship in her study was found to be highest of the lakeward side of the foredune where active sand deposition and associated grasses (Ammophila and Calamovilfa) were common. Although Keddy and Keddy (1984) found that mortality did not significantly differ between seedlings growing in clusters or individually, Ziemer (pers. comm.) arrived at different conclusions. In her study, seedling survivorship was found to be highest in areas where other seedlings occurred.

    Once established in the rosette form, mortality is low (Keddy and Keddy 1984). This is, in part, due to the fact that immature plants can withstand burial by up to 15 cm of sand (Weller in litt.) and possess taproots that often reach down 5 to 7 feet, to where available moisture lies (Pepoon 1927). Of 193 rosettes studied in Ontario by Keddy and Keddy (1984), only seven died (due in part to caribou trampling and human intervention). Plume moth (Platyptilia carduidactyla) larvae occur within the centers of rosettes but do not appear to cause mortality (Keddy and Keddy 1984). They can, however, cause injury to the apical meristem of the plant, resulting in a multibranched parental plant.

    Cirsium pitcheri is a monocarpic species which exists in a rosette for 5-8 years, f lowers the following year, then dies (Crispin and Penskar 1990, McEachern et al. 1989, Dobberpuhl and Gibson 1987). Plants can remain in the rosette form until enough resources have been obtained in the root system to fuel the bolting plant and subsequent seed production (Keddy and Keddy 1984). The proportion of juvenile to adult plants is not unexpectedly skewed in favor of juvenile plants, 71.8% : 28.2% in Door County and 69.8% : 31.2% in Manitowoc County, Wisconsin (Dobberpuhl and Gibson 1987).

    According to Keddy and Keddy (1984) in Ontario, plants in grassland habitat dominated by beach grass and horsetail produced over twice as many branches and flower heads than plants in the debris habitat or on a crescent beach. Those on the crescent beach were nearly all vertical. This branched growth form may be attributed to the abundance of plume moth (Platyptilia carduidactyla) larvae in the grass habitat (Keddy and Keddy 1984). Attacks, by these larvae typically result in multi-branched individuals, as discussed above.

    Growth of C. pitcheri plants is also hindered at times by spittlebugs which lay eggs in the meristems of the plants, damaging newly-forming leaves (Crispin and Penskar 1990). This apparently causes mortality in some plants.

    Flowering begins in late June, peaks in late July, then declines rapidly (McEachern et al. 1989, Loveless 198i). According to Loveless (1983), many plants are dead and dying by early August, but some continue flowering until mid-September. After four to seven@ days of blooming, flowers begin to wither and die (Keddy 1981). As flowers brown, the involucral bracts gradually close in around them, protecting developing seeds. Flower heads per stalk ,vary from two to as many as 125 (Keddy 1981).

    Flower tubes of C. pitcheri contain several microliters of sweet-scented nectar secreted by a ridge at the base of the style (Keddy 1981, Knuth 1908). Apparently, a wide array of potential pollinators are attracted to this nectar. Of the 10 species of insects listed as flower visitors in Ontario (Keddy and Keddy 1984) and 23 insect visitors observed by Loveless (1983) in Michigan, only one species was the same, a bumblebee (Bombus pextlexus) . Insect pollen vectors include species within the genus Bombus (bumblebees), Megachile (megachilid bees), Melissodes (anthophorid bees), Lasioglossum (smal1 halictid bees) , Agapostemon (large halictid bees) , and butterf1ies and skippers of several genera (Loveless 1983). Other visitors to the flowers include flies, wasps, honeybees and sedentary beetles and bugs (Loveless 1983). Keddy and Keddy (1984) listed lepidopterans, dipterans and hymenopterans as flower visitors in Ontario, the most abundant of which was Bombus vagans. Prominent butterfly pollinators included Vanessa cardui and Daneus peleyippus (Crispin and Penskar 1990). Nocturnal visitors have not been studied, but moths are believed to visit the flowers (Loveless 1983). For a species list of known pollen vectors and flower visitors, see Loveless (1983) and Keddy and Keddy (1984).

    Seed set is known to decline between late July and August in C. pitdheri. This decline in seed set has been attributed, in part, to pollinator availability which parallels this decline (Loveless 1983). Loveless (1983) observed that many plants died prior to maturing a single flower head, suggesting that the species allocates its resources early in the season when the likelihood of maturing fruits is highest.

    The artichoke plume moth (Platyptilia carduidactyla) larvae feed on the immature seeds of C. pitcheri, sometimes causing flower mortality (McEachern et al. 1989,, Keddy and Keddy 1984). This insect has been observer by Loveless (1983) in Michigan,, Keddy and Keddy (1984) in Ontario, and Dobberpuhl and Gibson (1987) in Wisconsin. In Ontario, Keddy and Keddy (1984) found that most plants were affected by the moth only in July, with predation highest in a grass habitat. Fewer plants were infected in a habitat of debris, while predation was non-existent in a crescent beach population. Loveless (1983), however, found that levels of seed damage in various habitats were nearly equal, suggesting that seed predation was density-dependant. In addition, Loveless observed that seed predation in Michigan did not markedly change throughout the season. For a brief description of the plume moth life cycle, see Keddy (1981). McEachern (pers. comm.) stated that she had observed a larva within the flower -head in Michigan but is unsure as to its identity at this time.

    Mosquin et al. (1986) suggested that the presence of the plume moth in C. pitcheri populations may be mutually beneficial. Presence of larvae in the rosettes of C. pitcheri causes the plant to become multi-branched (Keddy and Keddy 1984). As a consequence, more flowers and seeds are produced. At present, there is little information to substantiate this hypothesis. In addition, the moth is also known to feed on the seeds of the thistle, so there may be a simple trade off or net loss of seed production despite the multiple-branched stemming of the plant. Keddy and Keddy (1984), in fact, suggested that up to 40% of the normal seed crop was lost in a given year in Ontario as a result of the moth predation.

    American goldfinches were observed to devour approximately 50% of the seeds within a given flowerhead (Loveless 1984). other birds, primarily sparrows, forage on unburied seeds. The thirteen-lined ground squirrel (Spermophilus tridecemlineatus) is also known to prey on undispersed seed.

    Seeds are brown to purplish-brown, smooth, shiny, crescent-shaped achene6, measuring 7 mm X 2.5 mm (Keddy 1981). A pappus (an inverted cone of 55-65 fine hairs) is attached to the end of the achenes and aids in wind dispersal. Dispersal of seeds is also accomplished through burial of the entire receptacle (Keddy and Keddy 1984). The pappi are delicately attached to the fruits and are easily broken off, so most seeds remain intact within the seed heads (Keddy and Keddy 1984). These seed heads may remain attached to parental plants and become buried as they die and fall over (McEachern et al. 1989). or break off from the plant (Keddy and Keddy 1984). Seed dispersal by entire seed head greatly increases the likelihood that seeds will fall a short distance from the parent, into favorable habitat (Keddy and Keddy 1984). Ziemer (pers. comm.) found that the vast majority of seeds fell within 0.5-1.0 m from the parental plant. Long-distance dispersal is apparently not common (Ziemer pers. comm.) but may be accomplished primarily through the wave action (Keddy and Keddy 1984). Seed dispersal begins in late July and early August in Ontario (Keddy 1981).

    Density of C. pitcheri populations within Indiana Dunes National Lakeshore has been recently estimated. Within Indiana Dunes State Park, an estimate of 230 plants/ha with a 1:1 ratio of adults to juveniles was determined, while estimates of 1070 plants/ha with a 8.8:1 ratio of juvenile to adult plants were recorded at Miller. Nine adults and 69 juveniles were counted at Keiser (Bowles et al. 1985).


    >== 2500 EO-QUAL-DET

    This field is designed to help the field worker determine the quality (A=excellent, B=good, C--marginal, D=poor) of an occurrence of this element. These ranks are based on size and productivity of a population, vitality and vigor of individuals within a population, and size and quality of the habitat in which the element occurs. It should be noted that the headings (habitat, and population size and vigor) should be considered separately in determining overall quality of the element occurrence.

  • A) Population Size and Vigor: A population consisting of more than 5000 individuals. Existing plants occupy both juvenile and adult cohorts, indicating successful population maintenance.

    Habitat: Extensive: dynamic dune systems of more than 250 acres in size and greater than 2 miles in length with a' broad foredune. Dune processes have, not been altered in any unnatural way, nor are threatened by any unnatural event (development, off-shore constructions, etc.). Dune stabilization by plants is minimal and temporary and is part of a dynamic ecosystem.

    B) Population Size and vigor: A population of 500-5000 individuals occupying both juvenile and adult cohorts. Population structure is such as to maintain or enhance existing populations.

    Habitat: Dune systems 100-250 acres in size and 0.5-2 miles in length. Dune habitat is dynamic and open, without sign of alterations in natural dune system processes. Stabilization by plants is minimal,OR,, habitats of more than 250 acres in size that show moderate signs of stabilization and other hindrances of dune dynamics.

    C) Population Size and Vigor: A population of 100 to 500 individuals occupying both juvenile and adult cohorts, indicating successful population maintenance.

    Habitat: Dune systems 50-100 acres in size and 0.5-2 miles in length. Active dune systems of this size may begin to show problems with maintenance of appropriate C. pitcheri habitat, although such problems ' are only moderate. Stabilization of dune habitat by successional plants may be evident. Moderate fracturing of habitat due to development pressure, etc., may be noticeable, particularly in the smaller sites. Habitats of 100-250 acres in size that show significant problems with maintenance of open, dynamic dune environments are also of this rank.

    D) Population Size and Vigor: A population of less than 100 individuals; OR, populations larger than 100 individuals in which maintenance, as indicated through inappropriate age structures, is doubtful or of serious concern.

    Habitat: Dune systems of less than 50 acres in size and less than 0.5 miles in length. In such systems, dune processes have likely ceased to function adequately in maintaining the dynamic nature of the habitat. of f-shore and shoreline structures, fracturing of the landscape by development, fence and retaining wall construction, etc., may have added additional degradation to the habitat. Excessive stabilization of habitat by Schizachyrium scoparium, Ammophila breviligulata and shrubs has occurred in available habitat. Little likelihood of future recovery exists.

  • >== 3000 THREATS

    Cirsium pitcheri is apparently able to withstand occasional, but not frequent, disturbances (USFWS 1987). Habitat destruction through ATV use, human trampling (WI NHP 1990, Dobberpuhl and Gibson 1997) and other recreational activities (McEachern et al. 1989) appears to be a major threat to populations of the species. Sidle (1987) estimated that 5%-10% of the historic C. pitcheri habitat has been destroyed. It is probable that this estimate is low, and that a much larger percentage has also been negatively affected by a number of factors (listed below). Many populations, although still extant, have been reduced in size (Alverson 1981). As populations decrease in size, there is a reduced probability that recolonization of naturally disturbed areas will occur (Sidle 1987).

    Fragmentation of, and habitat destruction within dune f ields through road and retaining wall construction, sand mining (Nepstad 1981, Randall 1978) and lakeshore development (USFWS 1987, Keddy and Keddy 1984, Alverson 1981) prevents dispersal and reduces gene flow between existing populations (McEachern et al. 1989). Similar actions result in the alteration of local geomorphic processes necessary for dune formation and habitat maintenance.

    Artif icial dune stabilization through the action of exotic plant species (sweet clover, thistles, etc.) and land management agencies (plantings of white cedar, Ammophila breviligulata, etc.) has served to reduce in size and eliminate available habitat in many areas (McEach6rn et al. 1989, Dobberpuhl and Gibson 1987). Construction of off-shore structures such as jetties and on-shore fences can alter the dynamic dune processes essential for long-term habitation by C. pitcheri (Pavlovic pers. comm.).

    Fluctuating lake levels pose an immediate threat to populations that become established in areas subject to potential flooding. Dobberpuhl and Gibson (1987) reported that a population of 48 plants in Wisconsin had apparently been submerged by unusually high lake levels. These same high water levels pose an additional threat through excessive beach erosion (White 1981). Two severe storms caused major damage to populations at the Pukaskwa National Park in Ontario in 1986 (Mosquin et al. 1986). Flood waters from a raging creek and high waves off Lake Superior destroyed major portions of two populations. In the long term, however, it is these fluctuating lake levels that create the habitat necessary for the long-term survival of the species. Populations should not be artificially guarded by fences, walls or other structures that would impede on this dynamic process.

    Keddy (1988) stated that fire was a threat to C. pitcheri populations. In a fire at an Indiana site, seedlings died but rosettes and flowering plants survived. Those plants that survived responded by producing numerous shoots. It is likely that C. pitcheri, by evolving with frequent fires on the sand dunes along the Great Lakes, responds favorably to such events. In fact, these fires may be significant in the maintenance of open, unforested dune habitats. Gradual degradation of habitat through woody plant succession is an additional threat (White 1981).

    Some landowners have eradicated the plant in the belief that it is a noxious weed (USFWS 1987, Alverson 1981). Continued action of this sort could mark the demise of populations on private lands.

    Introgressive hybridization with non-native thistles (eg., C. vulgare) may be a concern for this species. Dobberpuhl and Gibson (1987) stated that a purple color form at the Sturgeon Bay Canal population in Wisconsin should be studied to determine its origin. This color has also been noted in Ontario populations (Keddy 1981).

    Keddy and Keddy (1984) estimated that the presence of the plume moth larvae in C. pitcheri has resulted in an estimated 14%-40% reduction in seed potential (depending on,habitat) in populations from Ontario. Mosquin et al. (1986), however, suggested that the plume moth and C. pitcheri may be mutually beneficial and may actually increase flower and consequently, seed production due to the numerous branches produced by injured plants. In order to determine the seriousness of this potential threat, additional research to determine to what extent seed set is hindered or enhanced by the moth is needed. This moth has been observed in Wisconsin (Dobberpuhl and Gibson 1987) and Michigan (Loveless 1983) as well.

    Parasitism in the form of a fungus has occurred on a number of plants in a moist, mossy area at the base of a dune blowout in Wisconsin (Dobberpuhl and Gibson 1987) . It is not known to what extent this fungus threatens the species.

    Herbivory on plants has been noted in the form of an unidentified hymenopteran larvae and a small mammal (Keddy and Keddy 1984). Nepstad (1981) stated that several juvenile plants had been destroyed by rabbits. Deer browse within Sleeping Bear Dunes National Lakeshore has been shown to pose little threat to thistle populations (Hazlett and van de Kopple 1983).


    >= 3500 LAND-PROT-SPECS

    Long beach fronts of substantial acreage are needed in order to ensure the continuance of the dynamic dune processes necessary for the long-term survival of the species. Without suf f icient protection from disturbance (construction of jetties, marinas, lakeshore residences, fence lines, retaining walls, ATV traffic, etc.), dune processes may become hindered. Suitable habitat coupled with adequate buffer (off-shore and on-shore) must be retained in order to guarantee the long-term survival of the species and element occurrences.


    >= 4000 RECOVERY-POT

    Most of the remaining populations of C. pitcheri are located on public lands: Indiana Dunes National Lakeshore (Indiana), Nordhouse Dunes area of Ludington State Park and the Huron-Manistee National Forest (Michigan), the Sleeping Bear Dunes and Pictured Rocks National Lakeshores (Michigan), two Michigan Nature Association Sanctuaries, five preserves managed by the Michigan Field Office of The Nature Conservancy, five Michigan state natural areas, a small stretch of Wisconsin shoreline on Lake Michigan managed by the US Coast Guard, and several state and county parks (Crispin and Penskar 1990, USFWS 1987). This fact alone does not ensure protection of the species, as was noted by Alverson (1981). In Ontario, much of the land on which C. pitcheri occurs is in private ownership (Keddy 1988). Two populations occur within provincial parks, while two others occur within Pukaskwa National Park.

    Establishment of new populations, if management requires, should be fairly easy to accomplish via seed collection, germination and transplantation of local seed stock. At present, there does not appear to be a strong need for this activity.


    >== 5000 BIOL-MONIT-NEEDS

    Monitoring is needed to assess the stability of C. pitcheri populations over time. In addition, the habitat within which the populations occur needs to be monitored in order to determine what effect changes in habitat have on Cirsium populations. For example, long-term monitoring of populations within foredune habitats should be monitored to ascertain the species' ability to respond to fluctuating water levels. In add tion, field surveys of potential habitat should also be made in order to determine to what extent C. pitcheri is colonizing new areas. This may be particularly useful in foredune areas that are now reforming after destruction by unusually high water levels in 1986 and 1987.

    Mosquin (1990) critiqued the monitoring program for C. pitcheri at Pukaskwa National Park. In a draft of the final form, he suggested that monitoring be concentrated in the following areas: (1) number of seedlings, rosettes and flowering plants, (2) number of heads and number of flowering heads, (3) number of heads affected by plume moth, and (4) total number of plants.

    Visitor traf f ic within C. pitcheri habitat" should be monitored during the summer months to ensure that excessive disturbance is not occurring. Other potential threats to habitat should also be monitored.


    >= 5200 BIOL-MONIT-PROCS

    Permanent plots should be established within representative populations occupying a wide array of habitat types. Monitoring of these plots should provide valuable information pertaining to the population biology and demographics of the species. Percent coverage with respect to associated plant species within the plots should also be monitored. Photopoints of the entire sampling area should be installed to capture large-scale changes in habitat. Monitoring should take place on a two or three year basis. For a methodology that has been used to monitor populations in the National Lakeshores, see McEachern et al. (1989).

    Care should be taken in monitoring the production of flowers as an indicator of seed production. According to Mosquin (1990), the growth of the thistle is essentially indeterminate and apparently produces flowers even through late July. According to Keddy (1981) these f lowers produced in late July would not have the time to mature seeds and hence should not be counted in monitoring programs. It seems essential that this distinction be made, but there looms the problem of determining whether a given f lower head will reach maturity before frost ends the growing season. Late-season monitoring of flower head production may need to be initiated to solve this problem.

    Monitoring programs need to be conducted several years in a row, at least initially, as extreme variations in year-to-year population numbers are common in the species (McEachern pers. comm., Mosquin 1990). Periodic censuses may lead to erroneous conclusions based on insufficient data. Seedling and adult establishment also varies dramatically from year to year.

    Field surveys of uncolonized habitat should be conducted every few years in areas of high C. pitcheri concentration. When discovered, new populations should be mapped and counted, with site survey forms completed for each new site. Such information would prove useful in determining the colonization abilities of the species.


    >== 5400 BIOL-MONIT-PROGS

    Monitoring is being conducted on three preserves owned by The Nature conservancy in Michigan (Ewert, pers. cozm.). At the Grass Bay Preserve, all individuals were counted between randomly selected transacts that are used to count another rare plant, Tanacetum huronense. The habitat occupied by individual plants is recorded with respect to one of the following types: beach, foredune, dune ridge, hind-dune, interdunal wetland or secondary dune components. At the Palmer-Gates-Wilcox Preserve, very small population numbers facilitate actual counts. These are conducted on an annual basis. The population occurring at Presque Isle Harbor Preserve is being monitored through counts of individual stems and flowering plants near a marina being developed by the Michigan DNR. Contact: Dave Ewert, Land Steward, Michigan Field Office, The Nature Conservancy, 2840 E. Grand River, Suite 5, East Lansing, MI 48823. Telephone No. (517) 332-1741.

    Monitoring of C. pitcheri populations has been initiated at three National Lakeshores: Pictured Rocks and Sleeping Bear in Michigan, and Indiana Dunes in Indiana. A complete field survey was conducted in 1989 to locate all populations within the three National Lakeshores. Two types of permanent,

    circular, 1/10 hectare plots were established for long-term population monitoring; 1) in which plants were marked, plotted and counted with respect to either seedling, juvenile or adult cohort, and 2) in which the total .number of plants were counted with respect to cohort within a given frame. Photopoints of the habitat were established and data on the overall plant community recorded at each site. For a detailed description of the methodology and the results of the first year's monitoring, see McEachern et al. (1989). A three-year inventory, monitoring study is scheduled to be completed in the summer of 1990, with information used to develop long-term management recommendations and monitoring plans for the species within National Lakeshores. Contact: Noel Pavlovic, Indiana Dunes National Lakeshore, 1100 N. Mineral springs Rd. Porter, IN 46304. Telephone No. (219) 926-7561. OR Kathryn McEachern, Department of Botany-Birge Hall, University of Wisconsin-Madison, 430 Lincoln Drive,, Madison, WI 53706. Telephone No. (608) 262-2593.

    The Wisconsin Field Office of The Nature Conservancy recently began to inventory populations at a registry site (Jackson Port Area Dunes). A 1989 inventory showed 20-30 adult flowering plants along a 1 mile stretch of lakefront. Additional monitoring is scheduled for alternate years at the site. A search was also conducted for the species at Mink River Preserve in 1989, but no plants were found. Monitoring will continue on a two-year cycle if populations can be ascertained at the site. Contact: Nancy Braker, Wisconsin Field office, The Nature Conservancy, 1045 E. Dayton St., Rm. 209, Madison, WI 53703. Telephone No. (608) 251-8140.

    A monitoring program for C. pitcheri at. Pukaskwa National Park in Ontario, Canada, has been running for 7-10 years (Bird pers. comm.). Currently, monitoring consists of tagging and mapping C. pitcheri individuals on an annual basis (Rivard pers. comm., Towndrow pers. comm.). A flash flood and severe storm destroyed portions of both populations and eroded and redeposited over 200 yards of sand along the beachfront. The monitoring program is also tracking the colonization of this open land by C. pitcheri. Contact: Don Rivard, Resource Management Specialist, Canadian Parks Service, Ontario Region'. 111 Water Street East, Cornwall, Ontario K6H 6S3. Telephone No. (613') 938-5933 or Chip Bird, Chief Park Warden, Pukaskwa National Park, Hattie Cove, Heron Bay,, Ontario POT 1RO. Telephone No. (807) 229-0801.


    >== 6010 RSRCH-NEEDS-COMM

    Additional information is needed on seed germination requirements. Under what specific conditions does,maximum seed germination occur? How long can C. pitcheri seeds remain part of the seed bank?

    At present, there seems to be some confusion about whether the plume moth is a parasite of C. pitcheri, or whether both share a mutual relationship. In order to determine the seriousness of this potential threat, additional research to determine to what extent seed set is hindered or enhanced by the moth is needed. This moth has been observed in Wisconsin, Michigan and Ontario populations. The relationship between the plume moth and an observed parasite of the moth as noted by Keddy and Keddy (1984) should also be studied.

    An additional research need centers around competition from perennial grasses for available nutrients. What is the optimal habitat for C. pitcheri with respect to competition from other plant species? Are artificial structures designed to protect populations of the plant resulting in increased competition and habitat loss via decreased wind throw of sand?


    >== 6410 RSRCH-PROGS-COMM

    Laura Ziemer, a graduate student at the University of Michigan, is studying seed dispersal capabilities, seedling survivorship, colonization success, and microsite preferences of Pitcher's thistle at the Grass Bay Preserve * Her master's thesis is expected to be completed in May, 1990. Contact: Laura Ziemer, 1201 Miller Avenue, Ann Arbor, MI 48103. Telephone No. (313) 7692784.

    Kathryn McEachern, a graduate student at the University of Wisconsin, Madison, is in the midst of a 3-year inventory and monitoring study at Indiana Dunes, Pictured Rocks and Sleeping Bear National Lakeshores. The goal is to relate metapopulation behavior to community and dune geomorphological processes in dune landscapes. It is hoped that the understanding of dune processes will facilitate better management and species persistence (Pavlovic pers. comm.). Contact: Kathryn McEachern, Department of Botany-Birge Hall, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI 53706. Telephone No. (608) 262-2593.


    >== 7010 MGMT-NEEDS-COMM

    Management must consider not only the thistle plants and their habitat, but also the roles of the pollinators and the plume moth (Keddy and Keddy 1984). Current fire policy in Wisconsin and perhaps elsewhere has favored shrub and tree succession in dune habitat (Dobberpuhl and Gibson 1987), which has undoubtedly increased the rate of succession. It is unknown how this policy is affecting the abundance of potential pollinators and the plume moth.

    In Wisconsin State Park personnel estimate that roughly 1/3 of the dune area at a single site has been removed during high lake levels (Dobberpuhl and Gibson 1987). similar erasure of foredune habitat occurred at Pukaskwa National Park in Ontario in 1985 and 1986 (Mosquin et al. 1986) and Indiana Dunes National Lakeshore during the high water levels of 1986 and 1987 (McEachern et al. 1989). Protection of habitat from this activity may in the long run, do more harm than good, by eliminating active dune processes and enhancing stabilization efforts by other dune plants (eg., Ammophila breviligulata).

    Protection and enhancement of the foredune and secondary dune system is a major management objective. Loss of active dune processes through retaining wall construction and fragmentation of existing habitat is a serious concern with which management must deal. Keddy's (1981) proposal of fence construction to protect populations in Pukaskwa National Park, Ontario, may alter sand deposition processes and increase dune stabilization rates.

    Populations need to be protected from the trampling of human feet during the summer months (Ewert pers. comm., Sidle 1987). Installation of boardwalks on dunes along pre-existing paths (Dobberpuhl and Gibson 1987) and the rerouting of existing trails (Mosquin et al. 1986) have been suggested as tools to reduce the risk of trampling.


    >== 7400 MGMT-PROCS

    Not only do natural lake level fluctuations account for the periodic removal of foredune habitat, but for the formation of habitat as well. According to Olson (1958) dunes should naturally reform during periods of low water, so no protective management against high water levels is needed. If man@made structures have been built to reduce the lateral drifting-necessary fordune processes, management might consider their removal. Such obstacles reduce bare sandy areas, facilitate erosion and increase the rate of successional habitation by Ammophila breviligulata and other plants, all detrimental to the long-term survival of C. pitcheri.

    Appropriate fire management may be an integral part in reducing the threat of successional change via stabilization of the dunes. Fire was undoubtedly a major factor in forming the character of the lakeshore dunes in presettlement times by reducing or eliminating successional species from the landscape (Pinus banksiana, Juniperus horizontalis, etc.). Although it is unknown at this time, large open areas may be essential for the pollinators of C. pitcheri.

    Construction of boardwalks should only take place if they have been shown not to have an impact on the natural dune formation regime, and then only where there is a need to discourage trampling.

    Restorations may become necessary if populations become, or are in danger of becoming, extirpated. Successful reintroduction should be fairly easy as seeds have been shown to germinate readily. If restorations are contemplated, local seed stock should be used if at all possible. Long-term survival of reintroduced populations rests on the maintenance of suitable habitat.

    According to Sidle (1987), conservation strategies should include the establishment and maintenance of large populations rather than numerous small colonies spread over the entire range of the species. Large populations have a greater ability to colonize newly-created habitat than small colonies. Yet, it may also be of importance to protect the small colonies if they are shown to harbor unique genetic alleles. Perhaps most important than all of the procedures listed above is the need for adequate preserve designs that take into account fluctuating water levels, long-distance dispersal and management needs (i.e., f ire). Without adequate buffer land, proper management may be very difficult to accomplish.


    >= 7710 MGMT-PROGS-COMM

    No active management outside of the diversion of trails and foot traffic from known populations is done by the Michigan Field Of f ice of The Nature Conservancy on any of its three preserves (Ewert, pers. comm.). Contact: Dave Ewert,, Michigan Field Office, The Nature Conservancy,, 2840 E. Grand River, Suite 5, East Lansing, MI 48823. Telephone No. (517) 332-1741.

    Management at the Jackson Port Area Dunes registry site in Wisconsin currently consists of informing the landowners of the significance of the species in hopes that they will not destroy the plant. Contact: Nancy Braker, Wisconsin Field Office, The Nature Conservancy, 1045 E. Dayton St., Rm. 209, Madison, WI 53763. Telephone No. (608) 251-8140.

    A management program is currently being developed for C. pitcheri at the Indiana Dunes -National Lakeshore. Contact: Noel Pavlovic, Botanist, National Park Service, Indiana Dunes National Lakeshore, 1100 N. Mineral Springs Rd.,,Porter, IN 46304. Telephone No. (219) 926-7561.

    Recommendations have recently been made toward the management of C. pitcheri populations at Pukaskwa National Park in Ontario,, Canada. A recent recommendation includes the enhancement of populations via outcrossing and the initiation of additional populations from seed at additional sites possessing appropriate habitat (Mosquin 1990). Contact: Don Rivard, Resource Management Specialist, Canadian Parks Service, Ontario Region, ill Water Street East, Cornwall, Ontario K6H 6S3. Telephone No. (613) 938-5933. OR, Chip Bird, Chief Park Warden, Pukaskwa National Park, Hattie Cove, Heron Bay, Ontario POT 1RO. Telephone No. (807) 229-0801.


    >= 8000 SUM-STEW-NEEDS

    Monitoring needs include the assessment of population stability at each site. In addition, habitat change, dispersal capabilities, population dynamics, and potential threats also need to be monitored. Research needs include efforts to reveal seed germination requirements, effects of plume moth/C. pitcheri interactions,, and effects of competition from species on long-term C. pitcheri survival. Management needs include an assessment of both the needs of C. pitcheri, but also those of its pollinators. Sites must be protected from excessive, unnatural disturbances and factors that may lead to the destruction of the dynamic dune processes imperative for C. pitcheri survival.


    >= 9000 BIBLIOGRAPHY

    Alverson, B. 1979. Wisconsin status report: cirsium pitcheri. Unpublished

    Wisconsin DNR report. 3 pp.

    Bird, C. 1990. Manager, Pukaskwa National Park, Ontario. Personal conversation with Wayne Ostlie, MRO, The Nature Conservancy.

    Bowles, M. L., W. J. Hess and M. M. DeMauro. 1985. An assessment of the

    monitoring program for special floristic elements at Indiana Dunes National Lakeshores. Phase II. Threatened and Special Concern Species. Unpublished report, Morton Arboretum, Lisle, IL. 375 pp.

    Cook, J. G., R. P. Lanka, J. L. Henszey, M. L. Neighbours, K. H. Dueholm, K. D. Kozie and S. H. Anderson. 1987. Midwest region rare species report. Section V: Literature Reviews of Rare Species Known to occur on National Park Service Lands, Midwest Region. 193 pp.

    Crispin, S. and M. Penskar. 1990. Cirsium pitcheri. Unpublished abstracts, Michigan Natural Features Inventory, Endangered Species, Manual. 2 pp.

    Dobberpuhl, J. M. and T. C. Gibson. 1987. Status surveys and habitat assessment of plant species: I. cirsium pitcheri (Torr.) T. & G. Unpublished Wisconsin DNR report, Project E-1, Study 808, Madison. 17 pp.

    Ewert, D. 1989. Botanist, Michigan -Field Office,, The Mature Conservancy. Personal communication: ESA questionnaire for cirsium pitcheri. 3 pp.

    Guire,, K. E. and E. G. Voss. 1963. Distributions of distinctive shoreline plants in the Great Lakes region. Mich. Bot. 2: 99-114.

    Harrison, W. E. 1988. Endangered and threatened wildlife and plants: Determination of threatened status for Cirsium pitcheri. Federal Register 53(137): 27137-27141.

    Hazlett, B. T. 1986. The terrestrial vegetation and flora of the mainland portion of Sleeping Bear Dunes National Lakeshore, Benzie and Leelanau counties, Michigan. Unpublished National Park Service report, Midwest Region, Omaha. 117 pp.

    Hazlett, B. T. and R. J. Vande Kopple. 1983. The terrestrial vegetation and flora of North and South Manitou Islands, Sleeping Bear Dunes National Lakeshore, Leelanau County, Michigan. Unpublished National Park Service report, Midwest Region, Omaha. 143 pp.

    Homoya, M. A. 1990. Botanist, Indiana Natural Heritage Program. Personal

  • communication: ESA questionnaire for Cirsium pitcheri. 2 pp.
  • Indiana Natural Heritage Program. 1989. Database records for Cirsium pitcheri. 4 pp.

    Johnson, M. F. and H. H. Iltis. 1963. Preliminary reports on the flora of Wisconsin. No. 48 (Compositae 1 - Composite Family 1). Wisconsin Acad. Sci. Arts Letters 52: 255-342.

    Keddy, C. 1988. Status report on the Pitcher's thistle (Cirsium pitcheri). Report to the Committee on the Status of Endangered Wildlife in Canada, Ottawa, Ontario. 17 pp.

    Keddy, C.. 1981. An ecological study of Cirsium pitcheri (Pitcher's thistle) in Pukaskwa National Park. Report to Parks Canada. 60 pp.

    Keddy, C. J. and P. A. Keddy. 1984,. Reproductive biology and habitat of Cirsium pitcheri. Mich. Bot. 23: 57-67.

    Loveless, M. D. 1983. Population biology and genetic organization in Cirsium pitcheri, , an endemic thistle. Kansas University doctoral dissertation, Lawrence. 109 pp. + appendices.

    Loveless, M. D. and J. L. Hamrick. 1988. Genetic organization and evolutionary history in two North American species of Cirsium. Evolution 42(2): 254-265.

    McEachern, K. 1990. Graduate Student, University of Wisconsin-Madison. Personal conversation with Wayne Ostlie, MRO, The Nature Conservancy.

    McEachern, K., J. A. Magnuson, and N. B. Pavlovic. 1989. Preliminary results of a study to monitor cirsium pitcheri in Great Lakes National Lakeshores. National Park Service Report, Indiana Duned National Lakeshore, Porter, IN. 96 pp.

    Michigan Natural Features Inventory. 1990. Database records for Cirsium pitcheri. 14 pp.

    Michigan Natural Features Inventory. 1989. Database records for cirsium pitcheri. 6 pp.

    Moore, R. J. and C. Frankton. 1974. The thistles of Canada. Canada Dept. Agric. Mon. 10. 109 pp.

    Mosquin, T. 1990. A review of monitoring procedures and management guidlines for the Pitcher's thistle (Cirsium pitcheti) in Pukaskwa National Park. Report prepared for the Canadian Parks Service, Pukaskwa National Park, Heron Bay, Ontario. 23 pp.

    Mosquin, T., L. Vien and V. Sahanatien. 1986. Cirsium pitcheri monitoring report, Pukaskwa National Park 1986, including management recommendations. Report to Parks Canada, Ontario Region. 26 pp. plus appendices.

    Ownbey, G. B. and Y. Hsi. 1963. Chromosome numbers in some North American species of the genus Cirsium. Rhodora 65: 339-354.

    Pavlovic, N. B. 1990. Botanist, Indiana Dunes National Lakeshore. Personal communication: ESA questionnaire for cirsium pitcheri. 3 pp.

    Pepoon, H. S. 1927. An annotated flora of the Chicago area. Chicago Acad. Sci., Chicago. 554 pp.

    Randall, C. 1978. Four threatened plants of the Great Lakes shorelines. Michigan Department of Natural Resources report, Lansing. 6 pp.

    Rivard, D. 1990. Resource Management Specialist, Canadian Parks Service, Ontario Region. Personal communication with Wayne ostlie, MRO, The Nature Conservancy.

    Sidle, J. G. 1987. Endangered and threatened wildlife and plants: threatened status for cirsium pitcheri. Federal Register 52(138): 2722927232.

    Stebbins, G. L. 1935. some observatiorw on the flora of the Bruce

    Peninsula, Ontario. Rhodora 37: 63-74.

    U S. Fish and Wildlife service. 1988a. Approved listing-rules. End. Spec. Tech. Bull. 13(g): 3.

    U S. Fish and Wildlife service 1988b. Final listing approved: Cirsium pitcheri as a threatened species. Federal register.

    U S. Fish and Wildlife service 1987. Listing protection proposed for eleven plants and animals.

    Endangered Species.Tech. Bull. 12(8): 1, 5-9.

    Weller, S. 1985. Personal communication, as documented in Bowles et al. (1985).

    White, J. 1981. Illinois element ranking form: Cirsium pitcheri. 1 pp.

    Wisconsin Natural Heritage Program (WI NHP). 1990. Database records for Cirsium pitcheri. 20 pp.

    Ziemer, L. 1990. Graduate student, University of Michigan, Ann Arbor. Personal communication with Wayne Ostlie MRO, The Nature Conservancy.


    >= 9900 UPDATE [YY-MM-DD]


    >= 9999 END