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BC Conservation Data Centre: Species Summary


Zeltnera exaltata
western centaury

 
Scientific Name: Zeltnera exaltata (Griseb.) G. Mans.
Scientific Name Synonyms: Centaurium exaltatum
English Name: western centaury
 
Classification / Taxonomy
Scientific Name - 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.
Classification Level: Species
Species Group: Vascular Plant
Species Code: ZELTEXA
Kingdom Phylum Class Order Family
Plantae Anthophyta Dicotyledoneae Gentianales Gentianaceae
   
Conservation Status / Legal Designation
Global Status: G3G4 (Mar 2025)
Provincial Status: S1S2 (Apr 2019)
BC List: Red
Provincial FRPA list:   
Provincial Wildlife Act:
COSEWIC Status:
SARA Schedule:
General Status Canada: 2 - May be at risk (2010)
   
Ecology & Life History
General Description: Western Centaury is an annual herb with usually unbranched stems that are 5-25 cm high. The basal leaves are lance-shaped to narrowly elliptic and 5-25 mm long, while those of the stem are longer and narrower. The leaves lack petioles and are opposite each other on the stem. Foliage is glabrous. One to a few erect flowers are borne on 1-4 cm long stalks 1-4 at the top of the stems. The white to light pink flowers have a slender, lobed calyx, 6-9 mm long, which tightly encloses a tubular corolla that flares at the top into 5 spreading petals that are ca. 4 mm long. The 5 stamens are exserted from the corolla tube. The fruit is a slender capsule nearly twice the length of the calyx at maturity.
Technical Description:
Diagnostic Characteristics: Members of the Gentian Family have opposite leaves, glabrous foliage, and tubular corollas with 4-5 equal lobes. C. EXALTATUM can be distinguished from other members of the family by its long, narrow corolla tube and by its lack of membranous tissue between the calyx lobes. A hand lens may be necessary for positive determination.
Identification Comments: Centaurium exaltatum is an annual herb with usually unbranched stems that are 5-25 cm high. The basal leaves are lance-shaped to narrowly elliptic and 5-25 mm long, while those of the stem are longer and narrower. The leaves lack petioles and are opposite each other on the stem. Foliage is glabrous. One to a few erect flowers are borne on 1-4 cm long stalks 1-4 at the top of the stems. The white to light pink flowers have a slender, lobed calyx, 6-9 mm long, which tightly encloses a tubular corolla that flares at the top into 5 spreading petals that are ca. 4 mm long. The 5 stamens are exserted from the corolla tube. The fruit is a slender capsule nearly twice the length of the calyx at maturity (Douglas et al. 1999).
Similar Species: Members of the Gentian Family have opposite leaves, glabrous foliage, and tubular corollas with 4-5 equal lobes. Centaurium spp. can be distinguished from other members of the family by the long, narrow corolla tube, lack of membranous tissue between the calyx lobes, and anthers that twist spirally after flowering. C. exaltatum is the only Centaurium species found in south central British Columbia and thus not likely to be mistaken for any other congener.
Provincial Reproduction Comments: Centaurium exaltatum has a annual life cycle, and reproduction is exclusively by seed. There is no information on primary pollinators, rate of seed production, or potential seed banks.
Provincial Ecology Comments: Little information is available on the biology and ecology of Centaurium exaltatum, including demographic characteristics such as flowering and recruitment rates; dispersal mechanisms; and intrinsic vulnerabilities to disturbance. As with many annuals of wetland habitats, population sizes likely fluctuate dramatically from year to year with changing moisture levels. However, it is unknown how far populations can decline in size before they become unviable. The existence of disjunct populations in British Columbia indicate a potential for long distance dispersal by seed, although the mechanisms of dispersal have not been identified.
Habitats:
(Type / Subtype / Dependence) 		Other Unique Habitats / Alkali Ponds/Salt Flats / Obligate
Other Unique Habitats / Vernal Pools/Seasonal Seeps / Facultative - frequent use
Global Habitat Comments: Zeltnera exaltata grows on stream banks, marshes, lakeshores, margins of hot springs and vernal pools, other wet, alkaline places often surrounded by desert (FNA 2023).
Provincial Habitat Comments: Centaurium exaltatum occurs in moist alkaline meadows, vernal alkaline depressions, wet areas along lake margins, and alkaline lake flats in the Bunchgrass zone, where it is typically associated with Saltgrass (Distichlis spicata) and/or Bulrush (Scirpus) plant communities. At Osoyoos Lake, it grows on a spit on silty soil at the edge of a lagoon with Juncus and Scirpus spp. At Mahoney Lake, it forms part of a Saltgrass community on highly alkaline flats around the edge of the lake. At Richter Pass, it grows in a roadside ditch in a depression forming a small pool with Scirpus spp., in the bare places where the water has receded. The pool is dry by summer's end. This is a slightly alkaline area in dry sagebrush hills, with Hordeum jubatum, Spartina gracilis, Distichlis spicata, Cirsium arvense, Castilleja minor ssp. minor (BC Conservation Data Centre 2010).
Provincial Phenology:
(1st half of month/
2nd half of month)
Provincial Phenology Comments: In British Columbia, Centaurium exaltatum flowers in late summer (late July to September). Peak flowering is in August. At the upland Richter Pass site, plants were just beginning to grow and were < 1 cm tall when observed on July 1, 1999 (BC Conservation Data Centre 2010).
Elevation (m) (min / max): Provincial:  270 / 560
Known Pests:
Pollen Vector:
Pollinator:
Dispersal:
   
 
Provincial Inventory
Inventory Priority:
Ownership of occurrences (Known locations): Mixed private/government
Inventory Need: Centaurium exaltatum has only been verified recently at Mahoney Lake (2009) and Osoyoos Lake (2001), British Columbia. Other EOs at Turtle Lake (Oliver), Kamloops Lake, and Richter Pass are either historical or have not been verified within the past 10 years (as of March 2010). Updated inventories are needed to determine if these EOs are still extant and whether they represent the full extent of the distribution in Canada.
 
Economic Attributes
 
Distribution
Endemic: N
Global Range Comment: Zeltnera exaltata is native to western North America from southern British Columbia south to southern Baja California Sur and east to New Mexico and Montana (FNA 2023). Range extent was estimated using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1994 and 2025 (RARECAT 2024, GBIF 2025, iNaturalist 2025, NatureServe 2025, SEINet 2025).
Disjunct, more common elsewhere: Y
Peripheral, major distribution elsewhere: Y
 
Authors / Contributors
Global Information Author: JM (1994), rev. Johnson, J. (2025)
Last Updated: Mar 27, 2025
Provincial Information Author: M. Miller
Last Updated: Mar 15, 2010
Last Literature Search:
   
References and Related Literature
Douglas, G.W., D. Meidinger, and J. Penny. 2002. Rare Native Vascular Plants of British Columbia, 2nd ed. B.C. Conserv. Data Centre, Terrestrial Inf. Branch, Victoria. 358pp.
Douglas, G.W., D. Meidinger, and J. Pojar. eds. 1999. Illustrated Flora of British Columbia, Vol. 3, Dicotyledons (Diapensiaceae through Onagraceae). B.C. Minist. Environ., Lands and Parks, and B.C. Minist. For., Victoria. 423pp.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 2025. Species Summary: Zeltnera exaltata. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 6, 2026).