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General Description: Aster jessicae is a robust, extensively rooting perennial that tends to grow in large clumps. Plants attain a height of 1.5 meters tall, but average about 1 meter. The herbage, particularly the upper portion, is covered with a dense, uniform, soft pubescence. Leaves are abundant and broadly lance-shaped. Middle stem leaves generally partially clasping the stem, and the lower leaves tend to dry and wither as the season progresses. Flower heads are usually numerous, with lavender-colored rays, 1 - 1.5 inches in diameter, and forming a broad cluster at the top of the plant. Plants flower from late July through September (Lorain 1991).
Technical Description: A robust, erect, perennial herb with thick creeping rhizomes. Plants tend to grow in large clumps and range from 0.4 - 1.5 meters tall, averaging ca. 1 meter. Upper herbage is densely and uniformly soft-pubescent or puberulent. Leaves are ample, broadly lanceolate, 6 - 13 cm long and 1.5 - 3.5 cm wide, and gradually reducing in size upward. Lower leaves abruptly petiolate and often deciduous. Middle cauline leaves are sessile, clasping and somewhat auricled based. Inflorescence paniculiform, usually with numerous radiate flower heads. Ray flowers are lavender/blue, 18 - 30 in number, and 12 - 20 mm long. Phillaries typically graduated in (4)5 - 6 imbricated series, strongly pubescent, appressed to somewhat loose, but not squarrose. Pappus tawny, soft, and about as long as the disk corollas. Achenes purple, slightly compressed, and pubescent (Cronquist et al. 1955).
Diagnostic Characteristics: Jessica's aster is generally found in remnant Palouse prairie communities and prairie/forest margins near canyon edges. Similar in general appearance to many other Aster species, it is distinguished by its usually robust nature, dense pubescence, and cordate leaf bases.
Jessica's aster is a particularly large, showy plant averaging 1 meter tall and tending to grow in large clumps of 10 - 50 stems or more. The upper portion of the plants are covered with short, dense, uniform hairs. This trait is quite distinct and relatively uncommon in the genus. Additionally, the middle stem leaves are sessile, clasping, and partially surround the stem. This combination of characters help distinguish Aster jessicae from other Aster species. The only other aster found in the general vicinity of Jessica's aster is Aster occidentalis var. intermedius A. Gray (Jones 1984). Compared to Jessica's aster, this second species generally inhabits more mesic microhabitats, has smaller flowers, is less robust (ca. 0.5 meters tall), possesses few to no hairs, and lacks the cordate leaf bases. Possible hybrids between these two taxa have been documented (Allen 1991).
Infraspecific Taxa: There are no infraspecific taxa for Aster jessicae.
Similar-appearing Taxa: Aster occidentalis var. intermedius is the only congeneric found in the general vicinity of Aster jessicae. The two species can be distinguished by several characters. Aster occidentalis var. intermedius has smaller flowers (about one-half the size), is less robust (about 0.5 m tall), has few to no hairs, and lacks cordate leave bases. Additionally, A. occidentalis var. intermedius generally inhabits more mesic habitats. Possible hybrids between the two taxa have been documented (Allen 1991).
Identification of this Taxon in Idaho: Similar in general appearance to many other Aster species, Aster jessicae is distinguished by its robust stature, dense pubescence, and cordate leaf bases.
Global Comments:
Idaho Comments: In 1986, Allen (1991) discovered an Aster jessicae-like plant near Grangeville, south of the species' known geographic range. This plant was later found to be a tetraploid (2n = 32), unlike all other A. jessicae plants, which are decaploid (2n = 80). She suspects this plant is a hybrid, perhaps involving A. cusickii and A. occidentalis.
Global: Aster jessicae is endemic to the Palouse region of southeastern Washington and adjacent Idaho. It is known from 61 extant sites in Idaho and 9 in Washington. Most occurrences consist of about 20 individuals. The few large occurrences contain approximately 100 genets with 500 - 1000+ flowering stems. In both states, nearly all populations are located exclusively on privately-owned land or County road right-of-ways. Three occurrences in Idaho are located on tribal-owned land within the Nez Perce Indian Reservation. Two occurrences in Washington are within the Washington Register of Natural Areas, a voluntary landowner conservation program.
It is assumed that A. jessicae formerly occupied much of the Palouse prairie region. It is now restricted to scattered remnant prairie and prairie/forest transition sites. Most of the species' original Palouse grassland habitat has been converted to crop agriculture. Agricultural consequences, such as the use of chemical herbicides and the invasion of aggressive weeds, has resulted in further habitat loss or degradation. Much of the area not plowed has been grazed by livestock for many years. Some level of timber harvest or clearing has taken place along much of the prairie-forest transition zone that is also A. jessicae habitat.
Existing threats are varied. Livestock graze at several sites and the proximity to agricultural fields and roads subjects some sites to chemical spraying and weedy species invasion. Heavy livestock grazing tends to alter plant community composition, including the invasion of weeds and the possible extirpation of A. jessicae. No direct threats due to disease, predation or light to moderate livestock grazing are known. Road and home construction continues to occur in areas known to support populations. Genetic and other demographic threats associated with the fact that A. jessicae persists only in small remnant populations remain unknown.
Only three new populations have been discovered in Idaho since Lorain (1991) compiled a range wide status report for the species in 1991. These add approximately 100 genets to the 1000 or so estimated by Lorain to occur in all Idaho occurrences at that time. Five historical collections from Idaho and seven from Washington contain vague location data. The disposition of the populations at these sites remains unknown.
Until the U. S. Fish and Wildlife Service revised their candidate system in early 1996, A. jessicae was a Category 1 (C1) candidate for listing under the Endangered Species Act. Under the revised system it is no longer considered a candidate species. The Idaho Native Plant Society ranks A. jessicae as globally rare. It was recommended for federal candidate status at the 1996 Idaho Rare Plant Conference. Aster jessicae is an Idaho BLM sensitive species, although no populations are presently known from public lands. The Idaho Conservation Data Center designation for A. jessicae is S2, indicating that in Idaho, the species is imperiled because of rarity or other factors demonstrably makes it vulnerable to extinction. Aster jessicae is listed as Threatened in Washington state by the Washington Natural Heritage Program. This category contains species likely to become endangered in the state within the near future if factors contributing to its population decline or habitat degradation or loss continue. Several other plant species endemic to the Palouse prairie region, such as Silene spaldingii and Haplopappus liatriformis, are also considered rare and vulnerable.
Idaho: Aster jessicae is on the Idaho Native Plant Society's globally rare plant list. It was recommended for reinstatement to the federal candidate list at the 1996 Idaho Rare Plant Conference.
Global: Aster jessicae is endemic to the Palouse region of southeastern Washington and adjacent Idaho. Most known extant populations are in Idaho, where it occurs in Clearwater, Latah, Lewis, and Nez Perce counties. In Washington, confirmed locations are known only from an area approximately 15 miles by 12 miles in Whitman County.
Idaho: Most documented extant populations of Aster jessicae are located in Idaho. The 61 state occurrences are located in the Palouse region, in Clearwater, Latah, Lewis, Nez Perce, and possibly Idaho counties. Specific localities in Idaho include the Troy vicinity (Latah Co.); upper Potlatch River and tributaries (Latah Co.); Central Ridge, Reubens vicinity, and Golden Ridge (Lewis Co); Potlatch Ridge, Angel Ridge, Nez Perce, and Gifford/Melrose vicinity; and Orofino/Gilbert, and Greer vicinities (Clearwater Co.).
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| Aster jessicae habitat |
Elevation (Global): 1600 to 3850 feet
Elevation (Idaho): 1600 to 3850 feet
Global: Aster jessicae occupies Palouse prairie grassland communities and prairie/forest transition zones. Within these communities, it occurs on shoulders, banks, slopes, and tops of draws. The most frequently encountered situation is for remnant populations to consist of scattered clumps of 5 - 10 individuals located in a small disturbed strip of vegetation between a road and adjacent cultivated field. Such habitats have open or partially open exposures with variable slopes (flat to 35%) and occur on a crest or upper slope position.Aspects vary, but most populations occur on western or southwestern aspects. Elevations range between 1600 and 3850 feet, though the species is generally found between 2500 - 2800 feet. Substrates are almost exclusively productive silt/loams (loess), moderately deep and sometimes gravelly. Aster jessicae usually grows in the vicinity of a stream or small intermittent drainage, but at some distance above inundated soils on drier ground.
Habitats supporting A. jessicae fall into five classified communities. Most of these sites, especially the forested habitats, have undergone past disturbance and are in secondary succession. The five habitat types, in order of their association with A. jessicae are: Pinus ponderosa/Symphoricarpos albus (ponderosa pine/snowberry)-by far the most common in Idaho; Festuca idahoensis/Symphoricarpos albus (Idaho fescue/snowberry); Crataegus douglasii/Symphoricarpos albus (black hawthorn/snowberry); Festuca idahoensis/Rosa nutkana (Idaho fescue/Nootka rose); and Pseudotsuga menziesii/Physocarpus malvaceus (Douglas-fir/ninebark). In Washington, A. jessicae is most frequently associated with Crataegus douglasii communities.
Common associates in Palouse prairie communities include Festuca idahoensis, Symphoricarpos albus, Rosa nutkana, Geum triflorum, Agropyron spicatum, Achillea millefolium, Potentilla gracilis, Rosa woodsii, and Crataegus douglasii. Often times these communities support scattered Pinus ponderosa trees or occur on the edge of ponderosa pine habitats. Species associated with the prairie/forest margins near the canyon edges and on lower slopes are Pinus ponderosa, Symphoricarpos albus, Rosa nutkana, Prunus virginiana, Pseudotsuga menziesii, Physocarpus malvaceus, Holodiscus discolor, Amelanchier alnifolia, Berberis repens, and Crataegus douglasii. Two of these species, Symphoricarpos albus and Rosa nutkana, are very consistent associates, and fairly easy to distinguish from adistance as an indicator of suitable habitat. Non-native weeds frequently occur with A. jessicae, with Hypericum perforatum, Phalaris arundinacea, and Phleum pratense being common associates. Some sites are quite degraded and very weedy, supporting high densities of Dipsacus sylvestris, Cirsium spp., and Dactylis glomerata.
Idaho: See Global Habitat comments.
Global: Remnant populations of Aster jessicae tend to consist of scattered clumps of individuals and occasionally dense patches. Most populations persist as scattered clusters along several miles of roadside in a vegetation strip between the road and a cultivated ield. Most populations contain less than 20 large plants, with 10 - 50 stems, averaging about one plant per square meter. Occasional sites with dense stands may support 3 - 4 large plants per square meter, with 100 - 200 stems per plant.
No A. jessicae populations are known to occur on cultivated or heavily grazed land. However, plants often are found along the edges of fields and pastures. Most sites are disturbed to some degree. It is also known from old, overgrown cemeteries and selectively logged woodland communities. Most forested communities that support A. jessicae are mid-seral. It does not appear A. jessicae requires disturbance. It does not seem to benefit from disturbance either, except perhaps if the disturbance is episodic rather than chronic. Nonetheless, it does seem tolerant to some level of habitat alteration or disturbance. Fire formerly was an integral component of the ecology of the Palouse grasslands and adjacent ponderosa pine communities. Fire suppression over the past century has altered plant community structure and composition. How, or if, this has affected A. jessicae is unknown. Fire suppression may be another factor contributing to the range and habitat reduction of A. jessicae.
Interspecific and intraspecific competition does not seem to be a significant problem at most sites, although weedy taxa such as Phalaris arundinacea, Hypericum perforatum, Dipsacus sylvestris, Cirsium spp., and Centaurea solstitialis are serious threats in some cases.
Idaho See Global Ecology comments.
Global: Aster jessicae reproduces by seed and vegetatively by rhizomes. Asexual reproduction from extensive rhizomes produces numerous large clumps in many populations. Most plants observed during field surveys contain many flowers. The flower heads of A. jessicae are not specialized for a particular pollinator. A variety of long-tongued insects, especially lepidopterans and hymenopterans have been observed visiting flowers and are the main suspected pollinators. Observed visitors include several lepidopterans (ochre ringlet, orange skipper, and sulphurs), as well as wasps, bees, and rove beetles. Specific details regarding seed dispersal are unknown. However, the achenes of A. jessicae have a well developed pappus adapted for wind dispersal.
Idaho: See Global Reproductive comments.
Phenology (Idaho): Flowering occurs in late summer, from late July through mid-September. Plants on exposed southerly slopes flower first, while semi-shaded sites on north and northwest aspects generally begin flowering in late August. Fruit and seed maturation occurs in September and early October. Seed dispersal likely occurs during middle to late October.
Global: The great majority of former grassland and adjacent grassland/forest transition communities in the Palouse region are now managed for crop production. Livestock grazing, timber harvest, and road and housing development are other long-standing land uses. Because of this widespread, drastic habitat loss, only small, scattered, remnant populations of Aster jessicae are still extant.
All known populations are located on private land or County road right-of-ways. It has been recommended that County governments be informed about the existence of A. jessicae along their roadways, and they protect populations during herbicide spraying and road maintenance activities. This would include Clearwater, Latah, Lewis,and Nez Perce counties in Idaho, and Whitman County in Washington (Lorain 1991). Several of the largest populations in Idaho have been recommended for protection (Lorain 1991). To date, this recommendation has not been acted upon. Lorain (1991) also noted that monitoring research could help in the species' conservation. She also recommended that the Nez Perce tribe monitor the status of the three A. jessicae populations known to occur on land they own.
Prior to the U.S. Fish and Wildlife's recent revision of their candidate system, A. jessicae was a category 1 (C1) candidate for listing under the Endangered Species Act. Under the revised system it is no longer considered a federal candidate. Aster jessicae was recommended for reinstatement to the federal candidate list at the 1996 Idaho Rare Plant Conference.
Idaho: See Global Management comments.
General Comments (Idaho): Extensive inventories have been completed in Clearwater, Latah, Lewis, and Nez Perce counties, Idaho, and Whitman County, Washington. The most comprehensive systematic survey in Idaho was conducted by Lorain when writing a status survey report for Aster jessicae (Lorain 1991). Dr. Geraldine Allen, from the University of Victoria, British Columbia, has also searched extensively for A. jessicae in Idaho as part of her ongoing research within the genus.
Inventory Needs (Idaho): Thorough inventories have been conducted for Aster jessicae throughout its range. A few areas potentially supporting suitable habitat for A. jessicae in Idaho have not been investigated, including tributaries of the Palouse River drainage and in the vicinity of Greer along the Clearwater River. Many of the creek canyons that feed into the various forks of the Palouse River are quite inaccessible and would require considerable time and energy to fully survey.
Allen, G. A. 1991. Letter dated March 14, 1991, to Chris Lorain outlining location and other information regarding Aster jessicae populations discovered during Dr. Allen's research.
Cronquist, A. 1955. Aster. Pages 71-98 in Vascular Plants of the Pacific Northwest, Part 5, by C. L. Hitchcock, A. Cronquist, M. Ownbey, and J. W. Thompson. University of Washington Press, Seattle.
Dean, R. D. 1966. A biosystematic study in the genus Aster, section Aster in western North America. Unpublished dissertation, Oregon State University, Corvallis.
Heidel, B. 1979. Endangered and threatened plants in the Northern Idaho BLM District. Bureau of Land Management, Coeur d'Alene, ID. 100 pp.
Henderson, L. F. 1899. Two new species of plants from the northwestern United States. Contributions to the U. S. National Herbarium 5: 201.
Jones, A. G. 1984. Typification of Aster jessicae Piper and reinstatement of A. mollis Rydberg (Asteraceae). Madrono 31: 113-122.
Kennison, J. A., and R. J. Taylor. 1979. Status report for Aster jessicae.
Author: M. Mancuso
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