Pontederia cordata

The species grows as an emergent plant, that is, in flooded conditions, so the plant is generally dependent upon aerenchyma in the stem to carry oxygen into the roots. Its metabolism is, however, also tolerant of low soil oxygen.Laing, H. E. (1940). Respiration of the rhizomes of Nuphar advenum and other water plants. American Journal of Botany, 27, 574–81. It is often found in areas where water levels fluctuate naturally, with spring flooding and later summer emergence. Apart from flooding, the species is also influenced by soil fertility, tending to grow in the more fertile bays of large lakes, for example. Like many aquatic plants, it is negatively affected by salinity and grazing.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p It is also negatively affected by competition from other wetland plants.Geho, E. M., Campbell, D., and Keddy, P. A. (2007). Quantifying ecological filters: the relative impact of herbivory, neighbours, and sediment on an oligohaline marsh. Oikos, 116, 1006–16. Like many wetland plants, it can survive unfavorable conditions as buried seeds in the soil.Whigham, Dennis F. and Robert L. Simpson. 1982. Germination and dormancy studies of Pontederia cordata L. Bulletin of the Torrey Botanical Club 109: 524–528. In a 36-year study on this species in a sinkhole pond, it was found to have an inverse relationship with American Lotus (Nelumbo lutea), declining in years with high American lotus abundance and increasing in years in with low American lotus abundance.{{Cite journal |last1=Geest |first1=EA |last2=Schuette |first2=B |date=30 December 2024 |title=A 36-year history (1978-2013) of the plant community in Pickerelweed Pond, a naturally occurring sinkhole pond in Missouri |url=https://monativeplants.org/wp-content/uploads/missouriensis/missouriensis-42/MONPS_42_24-41.pdf |journal=Missouriensis |volume=42 |pages=24–41}}

The plant flowers in late summer. The purple flowers have yellow markings which may assist in attracting bees for pollination.Sculthorpe, C. D. (1967). The Biology of Aquatic Vascular Plants. Reprinted 1985 Edward Arnold, by London. p. 280. Two species known to pollinate the flowers are Melissodes apicatus and Dufourea novaeangliae.Hutchinson, G. E. (1975). A Treatise on Limnology, Vol. 3, Limnological Botany. New York: John Wiley. p.229.Mitchell, T. B. (1962). Bees of the Eastern United States. North Carolina Agricultural Experiment Station Technical Bulletin 152(2): 1–557.

Once the plant begins to produce seeds, the stem supporting the inflorescence bends to submerge the fruits and seeds. Seeds are dormant at the time of dispersal and will not germinate without stratification for 6–8 weeks.

The flowers of the species are tristylous, meaning the styles of individual plants occur in three different morphs, with most populations containing all three. Leaf shape, which varies considerably across populations, within populations, and even within individuals, has been the source for many taxonomic synonyms.{{Citation

| last1 =Adanson

| first1 =Narukila

| last2 =Rafinesque

| first2 =Umsema

| last3 =Rafinesque

| first3 =Unisema

| contribution =Pontederia cordata

| year =2002

| title =Flora of North America

| volume =26

| page =45

| contribution-url =http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220010872

| publisher =Oxford University Press

}} Like many wetland and aquatic plants, the species can reproduce asexually by means of branching rhizomes, and hence can form large clonal stands.

File:Pickerelweed, Rideau River.jpg, Ontario]]

This plant is cultivated as an ornamental garden pond plant, and has gained the Royal Horticultural Society's Award of Garden Merit.{{cite web|title=RHS Plant Selector – Pontederia cordata|url=https://www.rhs.org.uk/Plants/13502/Pontederia-cordata/Details | access-date = 6 February 2021}}{{cite web | url = https://www.rhs.org.uk/plants/pdfs/agm-lists/agm-ornamentals.pdf | title = AGM Plants – Ornamental | date = July 2017 | page = 81 | publisher = Royal Horticultural Society | access-date = 12 May 2018}}

The young leafstalks can be eaten raw (with the unripe fruits stripped off) or cooked. The seeds are edible raw, and can be ground into grain.{{cite book |last1=Niering |first1=William A. |author-link1=William Niering| last2=Olmstead |first2=Nancy C. |title=The Audubon Society Field Guide to North American Wildflowers, Eastern Region |year=1985 |orig-date=1979|publisher=Knopf |isbn=0-394-50432-1 |page=711}}{{Cite book|last1=Elias|first1=Thomas S.|title=Edible Wild Plants: A North American Field Guide to Over 200 Natural Foods|last2=Dykeman|first2=Peter A.|publisher=Sterling|year=2009|isbn=978-1-4027-6715-9|location=New York|page=130|oclc=244766414|orig-date=1982}}

{{Reflist}}

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• [https://web.archive.org/web/20121116202931/http://plants.usda.gov/java/profile?symbol=POCO14 PLANTS Profile for Pontederia cordata]
• [http://planthardiness.gc.ca/ph_spp_intro.pl?speciesid=1005338 Pontederia cordata], Natural Resources Canada
• [http://www.flowersinisrael.com/Pontederiacordata_page.htm Pontederia cordata] Flowers in Israel

{{Taxonbar|from=Q621050}}

Category:Aquatic plants

Category:Pontederiaceae

Category:Edible plants

Category:Flora of Northern America

Category:Flora of Southern America

Category:Plants described in 1753

Category:Taxa named by Carl Linnaeus