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Damasonium californicum

Torr. ex Benth.

Fringed Water-plantain

G4Apparently Secure Found in 4 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.130799
Element CodePMALI03010
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicendemic to a single nation
KingdomPlantae
PhylumAnthophyta
ClassMonocotyledoneae
OrderAlismatales
FamilyAlismataceae
GenusDamasonium
Synonyms
Machaerocarpus californicus(Torr. ex Benth.) Small
Other Common Names
California Damsonium (EN) California damsonium (EN)
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.
Taxonomic Comments
FNA (vol. 22, 2000) transfers Machaerocarpus californicus to Damasonium californicum; these represent the same concept for the element.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-03-26
Change Date1986-07-14
Edition Date2025-03-26
Edition AuthorsN. Ventrella (2025)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Damasonium californicum is a perennial forb occurring in mud flats, vernal pools, and pond and stream margins of the western United States from Washington and Idaho south to California and Nevada, and historically in Montana. There are an estimated 100 occurrences of this species, which are potentially threatened by development, water diversion, alteration of hydrology, erosion, succession, recreational activities, invasive species, and other threats in some places. Little is known about threats and trends, and monitoring populations is important to improving our understanding of the status of Damasonium californicum.
Range Extent Comments
Damasonium californicum occurs in western North America, from Washington and Idaho south to California and Nevada in the United States (FNA 2000). In Montana it is known from a single historical collection in Lincoln County at a site inundated by Lake Koocanusa, and is likely extirpated (Lesica 2012). 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).
Occurrences Comments
By applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1994 and 2025, it is estimated that there are more than 100 occurrences rangewide (RARECAT 2024, GBIF 2025, iNaturalist 2025, NatureServe 2025, SEINet 2025).
Threat Impact Comments
Although threats are not widely documented, Damasonium californicum is likely threatened by development, water diversion, alteration of hydrology, erosion, succession, recreational activities, invasive species, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species.
Ecology & Habitat

Habitat

Damasonium californicum occurs in mud flats, vernal pools, and along the margins of ponds and streams from 100-1700 ft in elevation (Kartesz 1988, FNA 2000).
Palustrine Habitats
TEMPORARY POOLFORESTED WETLANDRiparian
Other Nations (1)
United StatesN4
ProvinceRankNative
WashingtonS1Yes
OregonSNRYes
MontanaSHYes
CaliforniaSNRYes
IdahoS2Yes
NevadaS2Yes
Threat Assessments
ThreatScopeSeverityTiming
Unknown/undetermined———

—

Plant Characteristics
DurationPERENNIAL
Economic Value (Genus)No
Roadless Areas (4)
California (2)
AreaForestAcres
Steele SwampModoc National Forest18,958
Timbered CraterLassen National Forest4,096
Oregon (2)
AreaForestAcres
Sky Lakes AWinema National Forest3,940
W. BoundaryWinema National Forest2,345
References (10)
  1. Flora of North America Editorial Committee (FNA). 2000. Flora of North America north of Mexico. Vol. 22. Magnoliophyta: Alismatidae, Arecidae, Commelinidae (in part), and Zingiberidae. Oxford Univ. Press, New York. xxiii + 352 pp.
  2. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  3. iNaturalist. 2025. Online. Available: https://www.inaturalist.org (accessed 2025).
  4. Kartesz, J.T. 1988. A flora of Nevada. Ph.D. dissertation. Univ. of Nevada, Reno. 3 volumes. 1729 pp.
  5. 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.
  6. Lesica, P. 2012a. Manual of Montana Vascular Plants. Botanical Research Institute of Texas, Fort Worth, TX. 771p.
  7. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  8. NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2024. Version: 1.1.1 (released Oct 01, 2024).
  9. Southwest Environmental Information Network (SEINet). 2025. Collections Databases. Online. Available: https://swbiodiversity.org/seinet/collections/index.php (accessed 2025).
  10. Washington Natural Heritage Program (WNHP). 2025. Online Field Guide to the Rare Plants of Washington. Online. Available: https://fieldguide.mt.gov/wa (accessed 2025).