(L.) Schoenl.
Identity
Unique IDELEMENT_GLOBAL.2.952411
Element CodePDCRA020C0
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVascular Plant
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomPlantae
PhylumAnthophyta
ClassDicotyledoneae
OrderRosales
FamilyCrassulaceae
GenusCrassula
SynonymsTillaea aquaticaL.
Other Common NamesTillée aquatique (FR)
Concept ReferenceFlora of North America Editorial Committee (FNA). 2009. Flora of North America north of Mexico. Vol. 8. Magnoliophyta: Paeoniaceae to Ericaceae. Oxford University Press, New York. xxiv + 585 pp.
Taxonomic CommentsThis record is for the broad treatment of Crassula aquatica, including C. saginoides as indistinct, as recognized by Moran in FNA (2009, vol. 8), Boyd (2012) and Weakley et al. (2025). Crassula aquatica has been recognized more narrowly, excluding C. saginoides as a distinct species by some treatments (e.g., Kartesz (1994, 1999)).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-09-19
Change Date2015-09-29
Edition Date2024-09-19
Edition AuthorsN. Ventrella (2024)
Threat ImpactUnknown
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank ReasonsCrassula aquatica is an annual aquatic forb found in coastal marshes, brackish mudflats, vernal pools, and along the margins of streams and ponds. It is a widespread species, occurring in North America, Mexico, and northern Eurasia, and as an introduced species in South America. There are an estimated 1,400 occurrences of this species, which are likely threatened by development, water diversion, alteration of hydrology, erosion, recreational activities, invasive species, flooding, and other threats in some places. Little is known about threats or trends, but with a large range extent, a high number of occurrences, abundant habitat, broad habitat preferences, and no obvious intrinsic vulnerabilities, Crassula aquatica is considered secure.
Range Extent CommentsCrassula aquatica is a widespread aquatic plant, occurring in North America, Mexico, and northern Eurasia, and as an introduced species in South America (FNA 2009, POWO 2024). In North America, it occurs from Alaska and the Northwest Territories south to California, east to Georgia, and from Minnesota and Ontario east to Maine and Newfoundland and Labrador in the United States and Canada (FNA 2009). Range extent was estimated to be over 150 million square kilometers using herbarium specimens, photo-based observations, and NatureServe Network occurrence data collected between 1993 and 2024 (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Occurrences CommentsBy applying a 1 km separation distance to herbarium specimens, photo-based observations, and NatureServe Network occurrence data documented between 1993 and 2024, it is estimated that there are more than 1,400 occurrences rangewide (GBIF 2024, iNaturalist 2024, NatureServe 2024, SEINet 2024).
Threat Impact CommentsAlthough threats are not widely documented, Crassula aquatica is likely threatened by development, water diversion, alteration of hydrology, erosion, recreational activities, invasive species, flooding, and other threats in some places, though there is insufficient data, including anecdotal accounts, to understand scope and severity of threats for this species.