Disclaimer:

The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

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Common name: featherfoil

Synonyms and Other Names: Androsace aquatica, Breviglandium palustre, Hottonia millefolium

featherfall, water-violet

Identification: Per Prankerd (1911) and Channel and Wood (1959):

Habit: rooted, submerged aquatic perennial, although can grow on exposed shores

Roots/Stems: submerged, rooted into sediment, occassionally floating or emergent stem

Leaves: submerged, alternate or whorled arrangement and pinnate shape

Flowers: single emergent inflorescence with pedicels (stalks) of showy purple/lilac petals (usually five-merous)

Fruits/Seeds: capsules with numerous small seeds

Look-alikes: There is one other species of Hottonia, H. inflata, which produces a rosette of floating, inflated, flowering stalks with much smaller flowers than H. palustris. Hottonia inflata is also a winter annual, while H. palustris is a summer perennial, although the flower concurrently. Myriophyllum and Proserpinaca species also appear similar in leaf shape to Hottonia, but have smaller flowers than those of H. palustris, lack inflated flowering stalks like with H. inflata, and have sessile instead of stalked inflorescences.

Native Range: Native to most of Europe and parts of Siberia

Alaska	Hawaii	Puerto Rico & Virgin Islands	Guam Saipan

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Ecology:  

Habitats: slow-moving waters and margins of lakes, ponds, ditches, and marshes (Rataj and Horeman 1977, Les 2018)

Tolerances: up to 50°F (10°C), meso- to eutrophic waters, low to moderate alkalinity (Rataj and Horeman 1977, Brock et al. 1989)

Life history: reaches peak growth in May, flowers in May through July, with seeds forming in June to July, and forms wintering buds (Rataj and Horeman 1977, Brock et al. 1989, Minchin and Boelens 2011)

Associated plants: Hydrocharis morsus-ranae, Stratiotes, Potamogeton perfoliatus, P. lucens, and Sparganium (Stodola 1967)

Means of Introduction: The popularity of this species in the water garden and aquarium trade means it is likely introduced as an intentional planting or aquarium release (Nichols et al. 2022).

The ability to regrow from stem fragments means this species can likely spread downstream and by hitchhiking on boats and waterfowl (Minchin and Boelens 2011, Lampinen and Metsäranta 2020).

Status: Within North America, large populations are present in British Columbia and New Hampshire, while small populations were found and eradicated or are under management in Maine, New York, and Michigan.

The population documented in 1994 in a pond in Groton, Connecticut was likely H. inflata given it was collected in November and the abundance of H. inflata in the pond (Nichols 2022).

Impact of Introduction:

Summary of species impacts derived from literature review. Click on an icon to find out more...

Ecological

Hottonia palustris potentially outcompetes submerged plants, including non-native Myriophyllum heterophyllum, due to early growth in Lake Winnipesaukee, New Hampshire (Nichols et al. 2022).

Remarks: Hottonia palustris exhibits a floral trait called heterostyly where styles of some plants will be longer and more extended from the floral tube than stamens, while other plants in the same population will have the reverse situation (Scott 1865, Brys et al. 2007). This reproductive strategy allows for greater chance of outcrossing of flowers by pollinators than selfing within the same flower (Baskin and Baskin 2014). However, a study of Hottonia palustis populations in its native range of Belgium found a negative relationship with population surface area and reproductive success, where smaller populations with a single style morphology had higher reproductive success (Vermeersch and Triest 2006).

References: (click for full references)

Baskin, C.C., and J.M. Baskin. 2014. Variation in Seed Dormancy and Germination within and between Individuals and Populations of a Species. Pages 277-373 in C.C. Baskin and J.M. Baskin, eds. Seeds. Second edition. Academic Press.

Brock, T.C.M., H. Mielo, and G. Oostermeijer. 1989. On the life cycle and germination of Hottonia palustris L. in a wetland forest. Aquatic Botany 35(2):153-166. https://doi.org/10.1016/0304-3770(89)90102-2.

Brys, R., H. Jacquemyn, and M. Hermy. 2007. Impact of mate availability, population size, and spatial aggregation of morphs on sexual reproduction in a distylous, aquatic plant. American Journal of Botany 94(1):119-127. https://doi.org/10.3732/ajb.94.1.119.

Channell, R.B., and C.E. Wood, Jr. 1959. The Genera of the Primulales of the Southeastern United States. Journal of the Arnold Arboretum 40(3):268-288. https://www.jstor.org/stable/43798510.

Foley, K., E. Haug, A. Smagula, and R. Richardson. 2024. Evaluation of Herbicide Efficacy on Hottonia palustris. Pages 59-60 in 64th Aquatic Plant Management Society Annual Meeting, St. Petersburg, FL, July 15-18, 2024.

Lampinen, J., and N. Metsäranta. 2020. Hottonia palustris L. (Primulaceae) – a new vascular plant for Finland found in Turku. Memoranda Societatis pro Fauna et Flora Fennica 96:32-37. https://journal.fi/msff/article/view/98602.

Les, D.H. 2018. Aquatic dicotyledons of North America: ecology, life history, and systematics. CRC Press, Boca Raton, FL.

Minchin, D., and R. Boelens. 2011. The distribution and expansion of ornamental plants on the Shannon Navigation. Biology and Environment: Proceedings of the Royal Irish Academy 111B(3):1-9. https://doi.org/10.3318/BIOE.2011.15.

Nichols, W.F., A.P. Smagula, A. Haines, and D. McGrady. 2022. Hottonia palustris (Primulaceae): A Newly Documented Nonnative Aquatic Plant Species in New Hampshire, U.S.A. Rhodora 123(994):221-228. https://doi.org/10.3119/21-13.

Prankerd, T.L. 1911. On the structure and biology of the Genus Hottonia. Annals of Botany 25(97):253-268. https://scholar.archive.org/work/c24eavbdo5gyxlxbalwo33gfgq/access/ia_file/crossref-pre-1923-scholarly-works/10.1093%252Foxfordjournals.aob.a089235.zip/10.1093%252Foxfordjournals.aob.a089318.pdf.

Rataj, K., and T.J. Horeman. 1977. Aquarium Plants. TFH Publications, Neptune City, NJ.

Scott, J. 1865. Observations on the Functions and Structure of the Reproductive Organs in the Primulaceae. The Journal of the Linnean Society. Botany 8:78-126. https://www.biodiversitylibrary.org/page/226637.

Stodola, J. 1967. Encyclopedia of Water Plants. TFH Publications, Neptune City, NJ.

Vermeersch, S., and L. Triest. 2006. Distylic Hottonia palustris shows high reproductive success in small populations despite low genetic variability. Aquatic Botany 84(4):354-358. https://doi.org/10.1016/j.aquabot.2006.01.004.

Author: Pfingsten, I.

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.