Primula alcalina - Cholewa & D. Henderson
Alkali Primrose
Taxonomic Status: Accepted
Related ITIS Name(s): Primula alcalina Cholewa & D. Henderson (TSN 504599)
Unique Identifier: ELEMENT_GLOBAL.2.129456
Element Code: PDPRI080Q0
Informal Taxonomy: Plants, Vascular - Flowering Plants - Primrose Family
Image 10816

© Idaho Conservation Data Center

Kingdom Phylum Class Order Family Genus
Plantae Anthophyta Dicotyledoneae Primulales Primulaceae Primula
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Concept Reference
Concept Reference: Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
Concept Reference Code: B94KAR01HQUS
Name Used in Concept Reference: Primula alcalina
Conservation Status

NatureServe Status

Global Status: G2
Global Status Last Reviewed: 30Jun2016
Global Status Last Changed: 21Mar2002
Ranking Methodology Used: Ranked by calculator
Rounded Global Status: G2 - Imperiled
Reasons: Known from eastcentral Idaho and southwestern Montana. Was thought to be extirpated from Montana until 2002. At this time there about 16 extant occurrences across the two states. Portions of its wet meadow habitat have been degraded at several sites by past management activities, but all extant populations appear to be stable. Threats could include alteration to hydrology and livestock grazing.
Nation: United States
National Status: N2

U.S. & Canada State/Province Status
United States Idaho (S2), Montana (S2)

Other Statuses

NatureServe Global Conservation Status Factors

Range Extent Comments: Primula alcalina is a narrow endemic known only from a series of wet alkaline meadows at the headwaters of four spring-fed creeks in east-central Idaho. These include Summit Creek in Custer County, Texas Creek in Lemhi County, Birch Creek in Clark and Lemhi counties, and Eighteen mile Creek in Lemhi County. A historical (1936) collection is known from meadows near Monida, Montana, but has never been relocated and is considered extirpated.

Area of Occupancy: 6-25 4-km2 grid cells
Area of Occupancy Comments:  

Number of Occurrences: 6 - 20
Number of Occurrences Comments: There are seven extant occurrences in Idaho and 9 extant and 1 historic occurrence in Montana. Per Bonnie Heidel, MTHP, the identity of the historic Montana specimen has been verified as Primula alcalina by the Flora North America author of the genus.

Population Size Comments: A historical (1936) collection is known from meadows near Monida, Montana, but has never been relocated and is considered extirpated. Estimated numbers of flowering plants at each occurrence ranges from 100,000-500,000 to 4,000. Total population sizes are probably at least twice these estimates, because nonreproductive plants are often more abundant than flowering individuals. Occurrence size estimates range from less than one acre to over 1000 acres, although P. alcalina occupies only a portion of these areas. For example, it occurs only along segments of creekside habitat at one of the sites. The total area where plants occur has been estimated at upwards of 440 acres (Moseley 1989).

Demographic parameters vary among and within populations, but in general, the species is abundant at all sites and appear stable. Demographic data indicate that populations are vigorous in terms of density, structure, and fecundity (Moseley 1995).

Overall Threat Impact: Unknown
Overall Threat Impact Comments: Disturbances which have resulted in at least local adverse effects to P. alcalina populations and its associated habitat include dam building, campgrounds, recreational trampling, road building, and livestock grazing. These continue to threaten portions of several populations. P. alcalina establishment and persistence seems to be restricted to specific hydrologic conditions related to water table depth and fluctuations (Mansfield and Miyasaki 1993). Because of this, water diversions, or other projects altering local hydrology would be deleterious to populations of P. alcalina. This species also seems to require open microsites for germination. Habitat changes that would result in an increase in competitive rhizomatous wetland species such as Carex simulata and Eleocharis pauciflora has been identified as a potential threat (Mansfield and Miyasaki 1993). Such a change would most likely be related to hydrological changes. Research concerning livestock grazing tentatively concluded that it may be detrimental to P. alcalina when occurring between the time of anthesis and seed dispersal. However, some removal of overtopping vegetation and creation of bare ground by grazers may be beneficial. There were no clear effects of grazing on numbers of mature plants, suggesting that potential adverse effects may be counterbalanced by potential benefits.

P. alcalina is an obligate outcrosser and probably insect pollinated. If so, pollinators are vulnerable to the spraying of insecticides. Such spraying probably does not take place in the wet meadows supporting P. alcalina, but wholesale spraying across southern Idaho rangelands for grasshopper control has been identified as a possible problem (Moseley 1989). No disease problems have been documented for P. alcalina (Moseley 1989).

Short-term Trend: Unknown
Short-term Trend Comments: Demographic monitoring showed generally decreasing fruit production but increasing recruitment and provided a basis for evaluating and planning grazing activity.

Other NatureServe Conservation Status Information

Global Range: Primula alcalina is a narrow endemic known only from a series of wet alkaline meadows at the headwaters of four spring-fed creeks in east-central Idaho. These include Summit Creek in Custer County, Texas Creek in Lemhi County, Birch Creek in Clark and Lemhi counties, and Eighteen mile Creek in Lemhi County. A historical (1936) collection is known from meadows near Monida, Montana, but has never been relocated and is considered extirpated.

U.S. States and Canadian Provinces
Color legend for Distribution Map

U.S. & Canada State/Province Distribution
United States ID, MT

Range Map
No map available.

U.S. Distribution by County Help
State County Name (FIPS Code)
ID Clark (16033), Custer (16037), Lemhi (16059)
MT Beaverhead (30001)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
10 Red Rock (10020001)+
17 Birch (17040216)+, Little Lost (17040217)+, Pahsimeroi (17060202)+, Lemhi (17060204)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
Basic Description: A perennial herb that produces a cluster of 3-10 flowers that are white with a yellow center and bloom in May and June. The flowers occur on an erect, leafless stem, 6.5-24 cm tall, emanating from a basal rosette of crinkle-margined, elliptic leaves.
General Description: Primula alcalina is a fibrous-rooted perennial with a basal rosette of leaves and a leafless flowering stem. Leaves are 1-4 cm long, narrowly elliptic with wavy or toothed margins, and taper gradually to a short, winged stalk. The leaf surfaces may have white flake-like farina when young but become mostly glabrous with age. The whitish-green flower stem reaches 6.5-24 cm in height and terminates in an unbranched umbel bearing 3-10 white tubular flowers 4-7 mm long with deeply cleft lobes that are 3-5 mm in length. The bracts below the inflorescence are lanceolate, covered with white farina and 4-7 mm long. The calyx has 5 pointed lobes, and is white farinose and 4-6.5 mm long. Fruit is a capsule.
Technical Description: Plants farinose only when young, efarinose in age. Scapose perennials with fibrous roots; leaves 1-4 cm long, elliptic-oblanceolate and narrowed gradually to the winged petiole, efarinose to farinose on the abaxial surface when young, the blade margins crenulate or denticulate, sometimes entire; scape 6.5-24 cm high, medium green proximally and darkened distally; inflorescence an umbel, farinose; involucral bracts 4-7 mm long, lanceolate, plane at base, the apex obtuse or acute; flowers distylous, 3-10 on nearly erect, farinose, purplish-green pedicels; calyx campanulate, 4-6.5 mm long, puberulent and somewhat farinose, sometimes with purplish blotches or striations, lobed 1/3 to 1/2 of its length, apex of the lobes generally acute, gland-tipped; corolla tube 4-7 mm long, lobes 3- 5 mm long and deeply cordate, white with yellow fornices; stamen ca 1.5 mm long, anthers located towards the middle of the corolla tube; stigma capitate, in pin plants located in upper third of corolla tube, positions reciprocal in thrum plants; pollen ca 10 microns in diameter in pin plants, ca 12 microns in diameter in thrum plants, exine microreticulate, 3 syncolpate; fruit a capsule; chromosome number: n=9 (Cholewa and Henderson 1984; Kelso 1987).
Diagnostic Characteristics: Primula alcalina is distinguished by its white corollas, generally (at least when mature) efarinose leaves, and small, distylous flowers (Cholewa and Henderson 1984). Albino flowers can be found in any species of Primula, but Kelso (1987) found that beyond these exceptional specimens, flower color is a very useful taxonomic character at both the sectional and species level.

Corolla color fading with age can cause identification problems. Flower color is deepest in buds and young flowers and gradually fades as the flower matures. This is particularly noticeable in the violet-flowered species of section Aleuritia (e.g. Primula incana), where older flowers on herbarium specimens can look almost white (Kelso 1987).

Reproduction Comments: Primula alcalina does not reproduce vegetatively. It is a diploid, distylous obligate outcrosser (Cholewa and Henderson 1984; Kelso 1991). Its relatively uncommon distylous breeding system known as distyly, refers to a floral polymorphism where two morphs (thrum and pin morphs) differ in relative placement of the style and stamens. P. alcalina is probably insect pollinated. Although specific pollinators are unknown, species of butterflies and bees have been observed visiting flowers (Fritts 1992).

During the spring, P. alcalina flowers were abundant at most sites studied by Muir and Moseley (1994). They found an average of 5.1 flowers per reproductive plant. In September, mean number of plants with mature fruits, and of mature fruits per fruiting plant were much lower than numbers of flowering plants and flowers per flowering plant, however. Relatively few plants had aborted fruits in September, suggesting removal of scapes or fruits (e.g., by livestock or small mammals) was more important than lack of seed set as a cause of the low numbers of plants with mature fruits.

The specific seed dispersal mechanisms are unknown for P. alcalina. In primroses studied by Kelso (1987), she found that as capsules ripen and elongation of the scape slows and eventually ceases, elongation and stiffening of the pedicels begins. In fruit, much elongation and stiffening occurs and the fruiting umbel looks very different from the blooming umbel. She speculated that these changes relate to seed dispersal; seeds are shaken out of the capsules by wind or passing animals, and erect elongated pedicels may increase dispersal distance from the parent plant. The process of pedicel elongation begins as scape elongation ceases, and is very rapid. This general development pattern is similar to what has been observed for P. alcalina, where pedicels elongate and stiffen through the growing season. By August, the pedicels are considerably longer than at anthesis and the capsules become erect from the somewhat nodding flower positions at anthesis.

Known Pests: No diseases or pests have been documented for Primula alcalina.
Ecology Comments: Communities containing Primula alcalina appear to be in an advanced successional stage, that is, they occupy stable landscape positions, and probably have for a long period of time (Moseley 1989). P. alcalina appears restricted to relatively stable habitats that exist along spring-fed creeks that have a fairly constant water flow, causing minimal fluctuations in the water table. It never occurs in meadows along creeks that are subject to seasonal fluctuations and channel scouring, such as caused by flooding during spring. Geomorphic processes that take place along streams of this type appear to preclude P. alcalina habitat (Moseley 1989; Mansfield and Miyasaki 1993). P. alcalina does not occur, or occurs at low density where there is continuous cover of densely tufted or rhizomatous graminoids. Conversely, higher densities are noted where space competition appears minimal, such as bare soil patches and on the side of hummocks (Moseley 1989). Density and other demographic parameters of P. alcalina were found to vary widely among and within sites studied by Muir and Moseley (1994), but causes for the differences could not be conclusively explained. Mansfield and Miyasaki (1993) found that the relationship between P. alcalina density and water table attributes is not linear. Demographic parameters investigated by Muir and Moseley (1994) found a mean of 34 plants per square meter. Numbers of nonreproductive individuals were usually either larger than or roughly equivalent to numbers that were flowering.

P. alcalina populations appear to tolerate a fairly broad range of livestock grazing regimes. It has coexisted with livestock for many years at some sites, and has persisted in areas excluded from livestock as well (Muir and Moseley 1994).

Habitat Comments: SUMMARY: Wet, alkaline meadows at the headwaters of spring-fed creeks in the large, intermontane valleys. The plants are found on low, relatively level benches adjacent to creeks and spring heads, often on the insides of meander loops, and also on low benches with hummocky topography, but only on the sides and tops of the hummocks. Elevations range from approximately 1920-2040 m. END SUMMARY. Primula alcalina occurs in wet, alkaline meadows, at the headwaters of spring-fed creeks in the large, intermontane valleys of east-central Idaho. Soils in the meadows are alluvial, alkaline, fine-textured, light-colored, and derived from outwash from the predominantly carbonate rocks of the Beaverhead, Lemhi, and Lost River ranges. Soil pH was determined during a demographic study of P. alcalina and found to average 8.9-9.6 at study sites (Moseley 1995). It occurs in the lowest topographic positions in the meadows, where the subirrigated soil is saturated to the surface throughout the growing season. Plants occur on low, relatively level benches immediately adjacent to creeks and spring heads, often on the inside of meander loops, and also on low benches with hummocky topography, where they are found only on the tops and sides the hummocks. While P. alcalina occurs on creek margins, the habitat is relatively stable hydrologically, as the creeks are entirely spring-fed and generally are subject to only minor seasonal or annual fluctuations in flow. Thus, water flows are relatively constant and there is little channel scouring. Elevations of the six populations range from 6,300 to 6,720 feet.

Communities supporting P. alcalina have not been quantitatively described in the literature. Vegetation on benches and hummocks supporting P. alcalina is dominated by Eleocharis pauciflora, Carex scirpoidea, Carex simulata, Kobresia simpliciuscula, and Juncus balticus. Deschampsia cespitosa and Muhlenbergia richardsonis are other common graminoids. Associated forbs are diverse, but not dominant, and include Dodecatheon pulchellum, Triglochin maritimum, and Thalictrum alpinum. Hummocks are often shared with shrubs, including several Salix species, Betula glandulosa, and Potentilla fruticosa. In several cases, meadows with P. alcalina also contain populations of other plant species rare in Idaho, including Kobresia simpliciuscula, Astragalus diversifolius, A. leptaleus, Lomatogonium rotatum, Phlox kelseyi kelseyi, Salix candida, and S. pseudomonticola.

Economic Attributes Not yet assessed
Management Summary Not yet assessed
Population/Occurrence Delineation Not yet assessed
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
NatureServe Conservation Status Factors Edition Date: 30Jun2016
NatureServe Conservation Status Factors Author: Heidel, B.; revised K. McConnell 10/01, rev. Treher (2016)
Element Ecology & Life History Edition Date: 11Apr1996
Element Ecology & Life History Author(s): M. Mancuso

Botanical data developed by NatureServe and its network of natural heritage programs (see Local Programs), The North Carolina Botanical Garden, and other contributors and cooperators (see Sources).

  • Cholewa, A.F., and D.M. Henderson. 1984. Primula alcalina (Primulaceae): a new species from Idaho. Brittonia 36(1): 59-62.

  • Fitts, R. 1992a. Review of the genus Primula in light of the ecology of Primula alcalina. Unpublished report. 8 pp.

  • Fitts, R. 1992b. The reproductive efficiency of Primula alcalina in differing habitats. Unpublished report. 3 pp.

  • Fitts, R. 1992c. Primula alcalina, summary of field notes May, June, and July 1992. Unpublished report. 4 pp.

  • Fitts, R. 1992d. Reproductive ecology, establishment and evolution of Primula alcalina. A proposal for Challenge Cost Share Program, USDI Bureau of Land Management, Salmon District Office, Utah State University and faculty advisors for the project. 7 pp.

  • Flora of North America Editorial Committee. 2009. Flora of North America North of Mexico. Vol. 8. Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press, New York. xxiv + 585 pp.

  • Gertschen, C. 1993. Primula alcalina. Unpublished report prepared for Biology Department, Boise State University, Boise, Idaho. 16 pp.

  • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

  • Keller, B. L. 1987. Analysis of the bat species present in Idaho, with special attention to the spotted bat, Euderma maculatum. Final Report. Department of Biological Sciences, Idaho State University. 25 pp.

  • Kelso, S. 1987. Systematics and biogeography of the arctic and boreal species of Primula. Unpublished dissertation, Univ. Alaska, Fairbanks.

  • Kelso, S. 1988. Evolution in the genus Primula sect. Aleuritia: isolation, secondary contact, polyploidy, and homostyly. In: abstracts for the American Institute of Biological Sciences meeting, Systematics section: Davis, California. [place of publication unknown]: American Institute of Biological Sciences: Abstract No. 602.

  • Kelso, S. 1991. Taxonomy of Primula sects. Aleuritia and Armerina in North America. Rhodora 93(873): 67-99.

  • Mansfield, D. H., and H. Miyasaki. 1993. Analysis of the habitat requirements of Primula alcalina. Challenge Cost Share Project, Albertson College of Idaho and Salmon District, Bureau of Land Management. 84 pp.

  • Moseley, R. K. 1989a. Report on the conservation status of Primula alcalina, a proposed candidate species. Prepared for Idaho Department of Parks and Recreation. 32 pp. plus appendices.

  • Moseley, R. K. 1989b. Field investigations of Leptodactylon pungens ssp. hazeliae (Hazel's prickly phlox) and Marabilis macfarlanei (Macfarlane's four-o-clock), Region 4 sensitive species on the Payette National Forest, with notes on Astragalus vallaris (Snake Canyon milkvetch) and Rubus bartonianus (bartonberry). 16 pp. plus appendices.

  • Moseley, R. K. 1992. Ecological and floristic inventory of Birch Creek Fen, Lemhi and Clark Counties, Idaho. Cooperative Challenge Cost-share Project, Targhee National Forest, Salmon District BLM, and Idaho Conservation Data Center, Idaho Department of Fish and Game. 29 pp.

  • Moseley, R. K. 1995b. Demographic monitoring of Primula alcalina (alkali primrose): 1991-1994. Conservation Data Center, Idaho Dept. of Fish and Game. 27 pp. plus appendices.

  • Muir, P. S. 1992. Distribution and status of Primula alcalina in Idaho. Unpublished report prepared for Bureau of Land Management, Salmon District Office. 34 pp + appendices.

  • Muir, P. S., and R. K. Moseley. 1994. Responses of Primula alcalina, a threatened species of alkaline seeps, to site and grazing. Natural Areas Journal 14: 269-279.

  • Smithman, L.C. 1989. Distribution and occurrence of Mentzelia mollis Peck. Unpublished report, Bureau of Land Management Vale District, Vale, OR. 41 pp.

  • U.S. Forest Service (USFS). No date. Idaho and Wyoming endangered and sensitive plant field guide. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Region. 192 pp.

  • U.S. Forest Service, Intermountain Region (USFS). 1990. Idaho and Wyoming endangered and sensitive plant field guide. U.S. Forest Service, Intermountain Region, Ogden, UT. 192 pp.

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