Flowering-rushButomus umbellatus L.
- Present in Alberta – Yes
- Global Invasive Species Database – Yes 
- NatureServe Rank – Medium
- Haber, Upland – No
- Haber, Wetland – Principal
- CWF, Status & Invasive Range – High, PQ, E. & S.W. Ontario, AB, BC, MN, NS
- Alberta Revegetation Guidelines – No
- The Nature Conservancy – Yes
- CBCN – Low
- AB Weed – Prohibited Noxious
Has been reported in Alberta, a serious invader in other regions. Since being listed as Prohibited Noxious, several extensive infestations have been found.
This plant can grow in submerged, emergent, and wet terrestrial environments. In the western part of it's range, it tends to grow in monotypic stands, reproducing vegetatively. This form is triploid (39 chromsomes), and more aggressive than the diploid (26 chromsomes) plants which occur in the east. Production of bulblets and seed is low in triploid plants, and they are self-sterile. They disperse mainly by fragmentation of rhizomes, so pulling can be counter-productive.
Recently (July 2012) AARD has had plants from St. Albert tested and found that they were diploid. Plants from other locations in Alberta tested to date are all Diploid. They would like to test samples from other populations. Contact: Nicole Kimmel Weed Specialist, Alberta Agriculture and Rural Development, Phone: (780) 422- 0885 email@example.com. They list differences between the two types as:
|Diploid Characteristics||Triploid Characteristics|
|self-compatible||self-sterile within clones|
|prolific flowering||infrequent flowering|
|high seed production||low production of sterile seeds|
|prolific bulblet production (rhizome & inflorescence)||inflorescence bulblet production not evident|
|partial dispersal by vegetative means||disperses only by rhizome fragmentation|
 Link to ISSG Global Invasive Species Database entry for Butomus umbellatus L.
Reported at Lake Isle boat launch - one flowering plant noted in a small patch July 6 2008 by Todd Kemper. Also previously reported in Alberta in the Red Deer area and along the river near Bow City. The Western Irrigation District canal from Calgary to Chestermere Lake is infested.
 Link to USDA Plants Profile, Butomus umbellatus L. - flowering rush
 Link to NatureServe I-Rank information for Butomus umbellatus - L. Flowering-rush