← Nymphaeales & magnoliids	Flora of New York — Acorales & Alismatales				→ Dioscoreales & Liliales
	Table of contents	Genus index	Protected species index	Invasive species index

The Acorales and Alismatales form the basal grade of the monocots (Lilianae), informally grouped as the "alismatid monocots."^[1]

monocots

Acorales : Acoraceae

	Acorus americanus (American sweetflag)

	Acorus calamus (old world sweetflag)

Alismatales

Tofieldiaceae—Triantha glutinosa (sticky false asphodel)

Araceae

Orontioideeae

	Orontium aquaticum (golden club)

	Symplocarpus foetidus (skunk cabbage)

Lemnoideae

	Spirodela polyrrhiza (common duckmeal)

	Lemna spp. (5 duckweeds)

	Wolffia spp. (3 watermeals)

Aroideae

	Calla palustris (wild calla, water arum)

	Peltandra virginica (green arrow arum, tuckahoe)

	Arisaema dracontium (green dragon)

	Arisaema triphyllum (4 Jack-in-the-pulpit subspp.)

Alismataceae

	Sagittaria spp. (9 arrowheads)

	Alisma spp. (3 water plantains)

Butomaceae—Butomus umbellatus (flowering rush)

Hydrocharitaceae

Hydrocharitoideae

	Hydrocharis morsus-ranae (European frog’s bit)

	Egeria densa (Brazilian waterweed)

	Limnobium spongia (American frog’s bit)

Stratiotoideae—

Anacharidoideae—Elodea spp. (3 waterweeds)

Hydrilloideae

	Najas spp. (8 water nymphs, naiads)

	Hydrilla verticillata (hydrilla, water thyme)

	Vallisneria americana (water celery, tape grass)

Scheuchzeriaceae—Scheuchzeria palustris (pod grass)

Aponogetonaceae (none in NY)

Juncaginaceae—Triglochin spp. (2 arrowgrasses)

Maundiaceae (none in NY)

Posidoniaceae (none in NY)

	Ruppiaceae—Ruppia maritima (widgeon grass, ditch grass)

	Cymodoceaceae (none in NY)

	Zosteraceae—Zostera marina (eel grass}

	Potamogetonaceae

Dioscoreales

Liliales

Asparagales

Poales

	Zingiberales

	Commelinales

alismatid
monocots

lilioid
monocots

commelinid
monocots

↑ Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 14, July 2017 (and more or less continuously updated since).

Clade	Order	Family	Subfamily	Tribe	Genus	Common names	#
alismatid monocots	Acorales	Acoraceae	—	—	Acorus	sweetflag	2
	Alismatales	Araceae	Orontioideae	Orontieae	Orontium	goldenclub	1
			Orontioideae	Symplocarpeae	Symplocarpus	skunk cabbage	1
			Lemnoideae	—	Spirodela	duckmeat	1
					Lemna	duckweed	5
					Wolffia	watermeal	3
			Aroideae	Calleae	Calla	callalily	1
				Peltandreae	Peltandra	arrow-arum	1
				Arisaemateae	Arisaema	Jack-in-the-pulpit	5
				Arisaemateae	Pinellia	pinellia	1
				Pistieae	Pistia	water-lettuce	1
		Tofieldiaceae	—	—	Triantha	tofieldia, false asphodel	1
		Hydrocharitaceae	Hydrocharitoideae	—	Egeria	waterweed	1
					Hydrocharis	frogbit	1
					Limnobium	spongeplant	1
			Anacharidoideae	—	Elodea	waterweed	3
			Hydrilloideae	—	Najas	waternymph, naiad	8
					Hydrilla	water-thyme	1
					Vallisneria	eelgrass	1
		Butomaceae	—	—	Butomus	flowering rush	1
		Alismataceae	—	—	Sagittaria	arrowhead	9
					Alisma	water-plantiain	12
					Helanthium	burhead	1
		Scheuchzeriaceae	—	—	Scheuchzeria	rannoch-rush	1
		Juncaginaceae	Juncaginoideae	—	Triglochin	arrowgrass	2
		Ruppiaceae	—	—	Ruppia	ditch-grass	1
		Zosteraceae	—	—	Zostera	eelgrass	1
		Potamogetonaceae	—	Potamogetoneae	Potamogeton	pondweed	36
				Potamogetoneae	Stuckenia	fineleaf pondweed	2
				Zannichellieae	Zannichellia	horned pondweed	1

Order Acorales

The order Acorales consists of only the Acoraceae (sweetflag family), with Acorus as its only genus.^[1]

↑ P. F. Stevens, (2001 onwards). "Acorales," Angiosperm Phylogeny Website. Version 13, September 28, 2013 (and more or less continuously updated since). http://www.mobot.org/MOBOT/research/APweb/orders/Acoralesweb.htm#Acorales.

Family Acoraceae

Acorus

Acorus calamus

Acorales — Acoraceae — Acorus
Genus Acorus	Sweetflag	N.Y. Status	Images	Distribution	NY NPT
Acorus americanus (Raf.) Raf. 1828. Acorus calamus var. americanus Raf. in… 1836. Acorus americanus (Raf.) Raf. in… 1954. Acorus calamus var. americanus H.Wulff	American sweet-flag, American sweetflag, Several-veined sweetflag, Sweetflag Acore d'Amérique, Acorus d'Amérique, Belle-angélique	Native, CoC: 5, Secure, Fertile diploid (2n = 2x = 24) OBL Perennial, Herb-forb, Sun		NYFA: 5 NYFA: 14 counties iNat 5 counties	USDA-N POWO Go Botany VASCAN ARS-GRIN ITIS FNA Tropicos NatureServe BONAP LBJ Images Wikispecies
Acorus calamus L. 1753. Acorus calamus L. in… 1764. Calamus aromaticus Garsault in… 1840. Acorus angustatus Raf. in…	Old World sweet-flag, European sweetflag, Single-veined sweetflag, Flag-root, Myrtle flag Acore roseau, Acorus roseau, Acore aromatique, Belle-angélique	Introduced from Asia, Sterile triploid (2n = 3x = 36) OBL Perennial, Herb-forb, Sun		NYFA: X iNat	USDA-X POWO Go Botany VASCAN ARS-GRIN ITIS FNA Tropicos NatureServe BONAP Images Wikispecies

Order Alismatales

The order Alismatales as defined in the Angiosperm Phylogeny Website.^[1]

↑ P. F. Stevens, (2001 onwards). "Alismatales," Angiosperm Phylogeny Website. Version 13, September 28, 2013 (and more or less continuously updated since). http://www.mobot.org/MOBOT/research/APweb/orders/Alismatalesweb.htm#Alismatales.

Family Araceae

The plants of the Araceae (arum family) have numerous small flowers that are part of a spadix, a spike inflorescence on which the flowers are borne on a fleshy stem. The spadix is usually surrounded by a bract called a spathe.

Subfamily Orontioideae

The Orontioideae contains just two New York species, both native: Orontium aquaticum (golden club) and Symplocarpus foetidus (eastern skunk cabbage). This subfamily also includes the genus Lysichiton which comprises the western and Asian skunk cabbages, neither of which are know to have naturalized in New York.

Orontium

Orontium aquaticum
golden club

Orontium aquaticum (golden club), the only living species of its grenus, probably reaches the northern extent of its range in New York and adjacent New England. It is considered to be threatened in New York, where it is mostly found in Hudson River tidal marshes but has been reported in acidic bogs and ponds farther inland.

Alismatales — Araceae — Orontioideae — Orontieae
Genus Orontium	Goldenclub	N.Y. Status	Images	Distribution	NY NPT
Orontium aquaticum L. 1753. Orontium aquaticum L. 1895. Aronia aquatica (L.) Baill.	Golden club	Native, CoC: 9, Threatened, NYNHP: 2^[1] OBL Perennial, Herb-forb, Part shade		NYFA: 2	USDA-N0 ARS-GRIN Tropicos BONAP LBJ Images Wikispecies
↑ New York Natural Heritage Program. 2024. Online Conservation Guide for Orontium aquaticum. Threatened, S2/G5.

Symplocarpus

Symplocarpus foetidus
skunk cabbage

Skunk cabbage (Symplocarpus foetidus) is the only North American native of the genus. The western skunk cabbage is in the genus Lysichiton and has not been reported to have naturalized in New York.

Alismatales — Araceae — Orontioideae — Symplocarpeae
Genus Symplocarpus	Skunk-cabbage	N.Y. Status	Images	Distribution	NY NPT
Symplocarpus foetidus (L.) Salisb. ex W.P.C.Barton 1753. Dracontium foetidum L. 1808. Spathyema foetida (L.) Raf. nom. inval. 1812. Symplocarpus foetidus (L.) W.Salisb. 1817. Symplocarpus foetidus (L.) Salisb. ex W.P.C.Barton 1818. Symplocarpus foetidus Nutt.	Skunk cabbage, Polecatweed Chou puant, Tabac-du-diable	Native, CoC: 5, Secure OBL Perennial, Herb-forb, Shade		NYFA: 5	USDA-NN ARS-GRIN FNA Tropicos LBJ Images Wikispecies

Subfamily Lemnoideae

Duckweeds:
• Spirodela polyrhiza (large),
• Lemna minor (medium),
• Wolffia arrhiza (small).

The Lemnoideae contains the small aquatic plants known as duckweeds, or water lentils. This subfamily contains plants previously placed in the Lemnaceae.

Spirodela

Spirodela polyrrhiza - common duck-meat

Common duck-meat (Spirodela polyrrhiza)

Alismatales — Araceae — Lemnoideae — Spirodela
Genus Spirodela	Duckmeat	N.Y. Status	Images	Distribution	NY NPT
Spirodela polyrrhiza (L.) Schleid. 1753. Lemna polyrhiza L. 1839. Spirodela polyrhiza Schleid. 1839. Spirodela polyrrhiza Schleid.^[1]	Common water-flaxseed, Common duck-meal, Common duck-meat, Greater duckweed, Giant duckweed Spirodèle polyrhize	Native, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-NN Go Botany VASCAN ARS-GRIN ITIS FNA Tropicos NatureServe BONAP Images Wikispecies
↑ "The initial ρ of a Greek word transliterated as rh, e.g. rhiza (ριζα, root, rhizome), should have an additional r added to it when preceded by a vowel, e.g. Glycyrrhiza (γλυκυρριζα, liquorice, from γλυκος, sweet, ριζα, root), leptorrhiza (λεπτορριζα, with a thin root, from λεπτος, small, slender), but as many reputable authors, Linnaeus among them, have omitted this additional r, it is best regarded as optional and an author's original spelling, as in Lemna polyrhiza, should be accepted." - W. T. Stearn (1992), Botanical Latin ed. 4: 261.

Lemna

Alismatales — Araceae — Lemnoideae — Lemna
Genus Lemna	Duckweed	N.Y. Status	Images	Distribution	NY NPT
Lemna minor L. 1753. Lemna minor L. 1771. Lenticula minor (L.) Scop. 1816. Lemna minima Thuill. ex P.Beauv. 1901. Hydrophace minor (L.) Bubani	Lesser duckweed	Native, CoC: 2, Secure		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Lemna trisulca L. 1753. Lemna trisulca L.	Star duckweed	Native, CoC: 4, Secure		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Lemna perpusilla Torr. 1843. Lemna perpusilla Torr.	Minute duckweed	Native, CoC: 4, Endangered, NYNHP: 1^[1]		NYFA: 1	USDA-NN Go Botany Images Wikispecies
Lemna valdiviana Phil. 1864. Lemna valdiviana Phil.	Pale duckweed, Valdivia duckweed	Native, CoC: 10, Endangered, NYNHP: 1^[2]		NYFA: 1	USDA-NN Go Botany Images Wikispecies
Lemna turionifera Landolt 1975. Lemna turionifera Landolt	Turion duckweed, Lenticulare turionifère	Native, CoC: 4, Unranked OBL		NYFA: U	USDA-NN Go Botany ITIS Images Wikispecies
Genus Lemna (excluded species)	Duckweed	N.Y. Status	Images	Distribution	NY NPT
Lemna gibba L. 1753. Lemna gibba L.	Swollen duckweed	N. America native, N.Y. excluded		NYFA-Excluded	USDA-N0 Images Wikispecies
Lemna obscura (Austin) Daubs 1965. Lemna obscura (Austin) Daubs 1867. Lemna minor var. obscura Austin	Little duckweed	N. America native, N.Y. excluded		NYFA-Excluded	USDA-N0 ARS-GRIN Images Wikispecies
↑ New York Natural Heritage Program. 2024. Online Conservation Guide for Lemna perpusilla. Endangered, S1/G5. ↑ New York Natural Heritage Program. 2024. Online Conservation Guide for Lemna valdiviana. Endangered, S1/G5.

Wolffia

Wolffia columbiana - Columbian watermeal

The genus Wolffia (watermeal) contains the world's smallest flowering plants, each an undifferentiated, rootless floating body. These species are often found in mixed populations in still ponds, lakes, and marshes in various parts of the state.

Alismatales — Araceae — Lemnoideae — Wolffia
Genus Wolffia Horkel ex Schleiden	Watermeal	N.Y. Status	Images	Distribution	NY NPT
Wolffia columbiana H.Karst. 1865. Wolffia columbiana H.Karst 1892. Grantia columbiana (H.Karst.) MacMill. 1912. Bruniera columbiana (H.Karst.) Nieuwl.	Columbian watermeal, Columbia watermeal, Columbian duckmeal Wolffie de Colombie	Native, Secure		NYFA: 5	USDA-NN Go Botany VASCAN Images Wikispecies
Wolffia borealis (Engelm. ex Hegelm.) Landolt 1868. Wolffia brasiliensis var. borealis Engelm. ex Hegelm. 1986. Wolffia borealis (Engelm. ex Hegelm.) Landolt	Dotted watermeal, Northern watermeal, Northern duckmeal Wolffie borèle	Native, Likely secure		NYFA: 4	USDA-NN Go Botany ARS-GRIN ITIS FNA Tropicos Images Wikispecies
Wolffia brasiliensis Wedd. 1849. Wolffia brasiliensis Wedd. ????. Bruniera punctata 1864. Wolffia punctata Griseb. ????. Wolffia papulifera	Brazilian watermeal	Native, Likely secure		NYFA: 4	USDA-N0 Go Botany ARS-GRIN ITIS FNA Images Wikispecies

Subfamily Aroideae

Tribe Calleae

Calla

Calla palustris - water arum

Calla palustris is the sole species of the genus and is native to cool wetlands of the Northern Hemisphere, including those in New York State.

Alismatales — Araceae — Aroideae — Calleae
Genus Calla	Callalily	N.Y. Status	Images	Distribution	NY NPT
Calla palustris L. 1753. Calla palustris L.	Wild calla, Water arum Calla des marais	Native, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-NN Go Botany VASCAN ARS-GRIN ITIS FNA Images Wikispecies

Tribe Peltandreae

Peltandra

Peltandra virginica

The genus Peltandra in New York contains the green arrow arum or tuckahoe (Peltandra virginica)

Alismatales — Araceae — Aroideae — Peltandreae
Genus Peltandra	Arrow-arum	N.Y. Status	Images	Distribution	NY NPT
Peltandra virginica (L.) Raf. ex Schott 1832. Peltandra virginica (L.) Raf. ex Schott	Green arrow arum, Green arrow-arum, Arrow arum, Poison arum, Tuckahoe	Native, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-NN Go Botany ARS-GRIN BONAP Images Wikispecies

Tribe Arisaemateae

The Arisaemateae includes two genera that can be found in New York: Arisaema and Pinellia. These include the plants known as Jack-in-the-pulpit and green dragon.

Arisaema

Arisaema triphyllum.
Jack-in-the-pulpit

Two species of Arisaema are native to New York: A. triphyllum (Jack-in-the-Pulpit) and A. dracontium (Green dragon).

Three subspecies of Jack-in-the-Pulpit have been reported in New York. A. triphyllum ssp. triphyllum, a tetraploid with 2n:56 chromosomes, likely originated as a hybrid of subspecies stewardsonii and pusillum, each of which is a diploid with 2n:28 chromosomes.^[1]

↑ M. Treiber (1980). "Biosystematics of the Arisaema triphyllum Complex." PhD Dissertation, University of North Carolina, Chapel Hill.

Alismatales — Araceae — Aroideae — Arisaemateae — Arisaema
Genus Arisaema Mart. sect. Pedatisecta^[1]	Jack-in-the-pulpit	N.Y. Status	Images	Distribution	NY NPT
Arisaema triphyllum (L.) Schott ssp. triphyllum 1753. Arum triphyllum L. 1832. Arisaema triphyllum (L.) Schott 1835. Arisaema atrorubens (Aiton) Blume	Common Jack-in-the-pulpit Indian Jack-in-the-pulpit Indian-turnip Arisème petit-prêcheur	Native, Secure FAC		NYFA: 5	USDA-N Go Botany VASCAN FNA Tropicos Images Wikispecies
Arisaema triphyllum (L.) Schott ssp. stewardsonii (Britton) Huttl. 1901. Arisaema stewardsonii Britton 1910. Arisaema triphyllum var. stewardsonii Stevens 1920. Arisaema triphyllum f. stewardsonii Engl. 1949. Arisaema triphyllum ssp. stewardsonii Huttl.	Stewardson's Jack-in-the-pulpit Swamp Jack-in-the-pulpit Arisème de Stewardson Arisèma de Stewardson	Native, Secure FAC		NYFA: 5	USDA-N VASCAN FNA Tropicos Images Wikispecies
Arisaema triphyllum (L.) Schott ssp. pusillum (Peck) Huttl. 1898. Arisaema triphyllum var. pusillum Peck 1901. Arisaema pusillum (Peck) Nash 1903. Arisaema acuminatum Small 1921. Arisaema triphyllum var. acuminatum Engl. 1940. Arisaema triphyllum f. pusillum Fernald 1949. Arisaema triphyllum ssp. pusillum Huttl.	Small jack-in-the-pulpit, Peck's jack-in-the-pulpit Arisème nain	Native, Vulnerable		NYFA: 3	USDA-N VASCAN FNA Tropicos Images Wikispecies
Arisaema triphyllum Arisaema triphyllum ssp. stewardsonii × Arisaema triphyllum ssp. triphyllum	Hybrid of Swamp Jack-in-the-pulpit & Common Jack-in-the-pulpit	Native, Unknown FAC		NYFA: U	Images Wikispecies
Genus Arisaema Mart. sect. Tortuosa^[1]	Green-dragon	N.Y. Status	Images	Distribution	NY NPT
Arisaema dracontium (L.) Schott 1753. Arum dracontium L. 1832. Arisaema dracontium (L.) Schott 1903. Muricauda dracontium (L.) Small	Green dragon, Dragon root, Dragon arum Arisème dragon, Arisèma dragon	Native, Likely secure		NYFA: 4	USDA-NN Go Botany VASCAN ARS-GRIN FNA Tropicos Images Wikispecies
↑ ^a ^b Susanne S. Renner, Li-Bing Zhang & Jin Murata (2004) "A chloroplast phylogeny of Arisaema (Araceae) illustrates Tertiary floristic links between Asia, North America, and East Africa." American Journal of Botany 91(6): 881-888.

Pinellia

Pinellia ternata

Pinellia ternata (crowdipper) is being tracked as a potentially invasive plant in New York and New Jersey.^[1]

↑ New York Species Record for Pinellia ternata (crowdipper) in iMapInvasives, updated 8/8/2016

Alismatales — Araceae — Aroideae — Arisaemateae — Pinellia
Genus Pinellia	Pinellia	N.Y. Status	Images	Distribution	NY NPT
Pinellia ternata (Thunb.) Makino 1784. Arum ternatum Thunb. 1837. Alocasia ternata (Thunb.) Raf. 1837. Atherurus ternatus (Thunb.) Blume 1901. Pinellia ternata (Thunb.) Makino	Crowdipper, Asian green dragon	Introduced from eastern Asia, Potentially invasive, NYIS Tier: Untiered, iMapInvasives, Invasive.org: [1], USGS: L48 not listed, Unknown naturalization, SNA Perennial, Herb-forb		NYFA: X NYFA: Kings County iNat GBIF 3 counties	Images Wikispecies

Tribe Pistieae

Pistia

Pistia stratiotes

Water lettuce (Pistia stratiotes) is now listed with an Ecological Invasiveness rank of Very High and placed in New York State Tier 2.^[1]

↑ New York State Invasive Species Tiers, Water lettuce (Pistia stratiotes).

Alismatales — Araceae — Aroideae — Pistieae
Genus Pistia	Water-lettuce	N.Y. Status	Images	Distribution	NY NPT
Pistia stratiotes L. 1753. Pistia stratiotes L. 1803. Pistia spathulata Michx. 1878. Pistia stratiotes var. spathulata Engl.	Water-lettuce, Tropical duckweed, Nile cabbage Laitue d'eau	Introduced from US South, South America, Africa, Very highly invasive, NYIS: 62%^[1], Impersistent		NYFA: 2 counties iMap: 3 counties iNat: 5 counties NYFA: X	USDA-N0 Go Botany VASCAN ARS-GRIN ITIS Tropicos Images Wikispecies
↑ New York non-native plant invasiveness assessment – Pistia stratiotes: Not Assessable (62).

Tribe Colocasieae

Colocasia

Colocasia esculenta

Alismatales — Araceae — Aroideae — Colocasieae — Colocasia
Genus Colocasia	Taro	N.Y. Status	Images	Distribution	NY NPT
Colocasia esculenta (L.) Schott 1753. Arum esculentum L. 1801. Caladium esculentum (L.) Vent. 1832. Colocasia esculenta (L.) Schott 1832. Colocasia esculenta var. esculenta 1832. Colocasia antiquorum Schott 1856. Colocasia antiquorum var. esculenta (L.) Schott	Coco yam ⓘ	Introduced, Highly invasive		NYFA-Excluded NYFA: Not listed xx counties	Images Wikispecies

Family Tofieldiaceae

Triantha

Alismatales — Tofieldiaceae
Genus Triantha	Tofieldia	N.Y. Status	Images	Distribution	NY NPT
Triantha glutinosa (Michx.) Baker 1803. Narthecium glutinosum Michx. 1879. Triantha glutinosa (Michx.) Baker	Sticky false-asphodel	Native, Endangered		NYFA: 1	USDA-NN Go Botany LBJ Images Wikispecies

Family Alismataceae

The Alismataceae (water-plantain family) has about a dozen documented taxa in three genera growing outside of cultivation in New York.

Sagittaria

Sagittaria latifolia
broad-leaved arrowhead

Alismatales — Alismataceae — Sagittaria
Genus Sagittaria	Arrowhead	N.Y. Status	Images	Distribution	NY NPT
Sagittaria latifolia	Broad-leaved arrowhead, Wapato, Common arrowhead, Duck-potato	Native, CoC: 3, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-N Go Botany Images Wikispecies
Sagittaria rigida	Sessile-fruited arrowhead	Native, CoC: 6, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-N Go Botany Images Wikispecies
Sagittaria graminea ssp. graminea	Grass-leaved arrowhead	Native, CoC: 8, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-N Go Botany Images Wikispecies
Sagittaria cuneata	Northern arrowhead, Wapato, Wapatum arrowhead	Native, CoC: 6, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Sagittaria engelmanniana	Acid-water arrowhead, Engelmann arrowhead	Native, CoC: 9, Likely secure OBL Perennial, Herb-forb		NYFA: 4	USDA-N Go Botany Images Wikispecies
Sagittaria subulata	Strap-leaved arrowhead	Native, CoC: 7, Rare OBL Perennial, Herb-forb		NYFA: 3	USDA-N Go Botany Images Wikispecies
Sagittaria montevidensis ssp. spongiosa Lophotocarpus spathulatus Lophotocarpus spongiosus Sagittaria spathulata Sagittaria calycina var spongiosa	Spongy-leaved arrowhead, Tidal arrowhead, Spongy arrowhead, Hooded arrowhead	Native, CoC: 7, Threatened OBL Annual, Herb-forb		NYFA: 2	USDA-N Go Botany FNA Images Wikispecies
Sagittaria teres	Slender arrowhead, Quill-leaved sagittaria	Native, CoC: 10, Endangered OBL Perennial, Herb-forb		NYFA: 1	USDA-N Go Botany FNA Images Wikispecies
Sagittaria australis (J.G.Sm.) Small 1897. Sagittaria longirostra var. australis J.G.Sm. 1903. Sagittaria australis (J.G.Sm.) Small auct. Sagittaria engelmanniana ssp. longirostra non Micheli 1955 auct. Sagittaria longirostra non J.G.Sm.	Longbeak arrowhead, Appalachian arrowhead	N. America native, N.Y. excluded		NYFA-Excluded	USDA-N Go Botany ARS-GRIN FNA Tropicos Images Wikispecies

Alisma

Alisma subcordatum

Three species of water-plantains (genus Alisma) have been reported in New York State.

Alismatales — Alismataceae — Alisma
Genus Alisma	Water-plantain	N.Y. Status	Images	Distribution	NY NPT
Alisma subcordatum Raf. 1808. Alisma subcordatum Raf. in Med. Repos., ser. 2, 5:362 1813. Alisma parviflorum Pursh in Fl. Amer. Sept. 1:252 1824. Alisma plantago-aquatica var. parviflorum (Pursh) Torr. in Fl. N. Middle United States 1840. Alisma montanum Raf. in Autik. Bot.:62 1962. Alisma plantago-aquatica ssp. subcordatum (Raf.) Hultén in Kongl. Svenska Vetensk.	American water-plantain Southern water-plantain Broad-leaved water-plantain Small water-plantain Alisma subcordé	Native, CoC: 4, Secure, S5, G5 OBL Perennial, Herb-forb		NYFA: 24 counties iNat: 16 counties GBIF: present in NY	USDA-N COL WFO POWO FSUS Go Botany VASCAN FNA Images Wikispecies
Alisma triviale Pursh 1808. Alisma roseum Raf. in Med. Repos., nom. nud. 1813. Alisma triviale Pursh in Fl. Amer. Sept. 1:252 1817. Alisma odoratum Raf. in Fl. Ludov.:17 1830. Alisma plantago-aquatica var. americanum Schult. & Schult.f. 1888. Alisma plantago-aquatica var. triviale (Pursh) Britton, Sterns & Poggenb. 1900. Alisma brevipes Greene in Pittonia 4:158 1908. Alisma superbum Lunell in Bull. Leeds Herb. 2:5 1908. Alisma superbum var. angustissimum Lunell in Bull. Leeds Herb. 2:5 1908. Alisma superbum var. lanceolatum Lunell in Bull. Leeds Herb. 2:5 1914. Alisma subcordatum var. superbum (Lunell) Lunell in Amer. Midl. Naturalist 1932. Alisma plantago-aquatica ssp. brevipes (Greene) Sam. in Ark. Bot. 24A(7):19 1935. Alisma plantago-aquatica var. brevipes (Greene) Vict. in Fl. Laurent.:615	Northern water-plantain Alisma commun	Native, CoC: 4, Secure, S5, G5 OBL Perennial, Herb-forb		NYFA: 13 counties iNat: 13 counties GBIF: present in NY	USDA-N COL WFO POWO FSUS Go Botany VASCAN FNA Images Wikispecies
Alisma gramineum Lej. 1811. Alisma gramineum Lej. in Fl. Spa 1:175 1827. Alisma plantago-aquatica var. gramineum (Lej.) Dumort. in Fl. Belg.:135 1843. Alisma geyeri Torr. in I.N.Nicollet, Rep.Hydrogr.Mississippi:162 1851. Alisma plantago-aquatica var. graminifolium Lange in Haandb.Danske Fl., nom. illeg. 1903. Alisma graminifolium Glück in Beibl. Bot. Jahrb. Syst. 73:33 1957. Alisma gramineum var. angustissimum (DC.) Hendricks in Amer. Midl. Naturalist	Narrow-leaved water-plantain Grass-leaved water-plantain Ribbon-leaf water-plantain Alisma graminoide	Native, CoC: 7, Threatened, S4, G5 OBL Perennial, Herb-forb, 2n=14		NYFA: 2-3	USDA-N COL WFO POWO Go Botany FNA Images Wikispecies

Helanthium

Helanthium tenellum

The species Helanthium tenellum (Mart. ex Schult.f.) J.G.Sm. (mud-babies or dwarf burhead) is not known to persist New York State, though specimens were collected from Queens County in 1921.

Alismatales — Alismataceae — Helanthium
Genus Helanthium	Burhead	N.Y. Status	Images	Distribution	NY NPT
Helanthium tenellum (Mart. ex Schult.f.) Britton 1830. Alisma tenellum Mart. ex Schult.f. in J.J.Roemer & J.A.Schultes, Syst. Veg. 1833. Alisma ranunculoides var. brasiliense A.St.-Hil. in Voy. Distr. Diam. 2:432 1856. Echinodorus subulatus Engelm. in A.Gray, Manual, ed. 2:438 1856. Echinodorus parvulus Engelm. in A.Gray, Manual, ed. 2:439 1868. Echinodorus tenellus (Mart. ex Schult.f.) Buchenau in Index Crit. Butom. Alism. 1898. Sagittaria tenella (Mart. ex Schult.f.) Kuntze in Revis. Gen. Pl. 3(2): 326 1905. Helanthium tenellum (Mart. ex Schult.f.) J.G.Sm. in N.L.Britton 1909. Helanthium parvulum (Engelm.) Small in N.L.Britton & al. 1955. Echinodorus tenellus var. ecostatus Fassett in Rhodora 57:184 1955. Echinodorus tenellus var. parvulus (Engelm.) Fassett in Rhodora 57:185 1955. Echinodorus tenellus fo. randii Fassett in Rhodora 57:188	Dwarf burhead Mud-babies Pygmy chain sword	Native, CoC: 10, Likely extirpated, SX, G5 OBL Perennial, Herb-forb		NYFA: Queens (1921) iNat: No NY obs. GBIF: Not present in NY	USDA-NN Go Botany ARS-GRIN ITIS FNA Tropicos Images Wikispecies

Family Butomaceae

Butomus

Butomus umbellatus
flowering rush

The sole species of Butomaceae (the flowering rush family) is the aquatic Eurasian plant Butomus umbellatus, which is listed as moderately invasive in New York. Its first appearance in North America was in the St. Laurence River in 1897, and it is now a problem weed in the Great Lakes.^[1]

Studies by L. C. Anderson in 1974 found that the naturalized North American Butomus populations had separate sources. Those east of Niagara Falls, introduced near the St. Lawernce River, originated in eastern Asia. Those west of the Falls were introduced near Detroit, and were from western Euraasia. R. L. Stuckey, in 1994, recognized these two groups as separate species, with B. umbellatus, from western Eurasia, found west of the Falls, and B. junceus, from eastern Asia, found east of the falls.^[2] B. junceus is not widely accepted as a separate species at this time, but if it were to be accepted, New York's populations would probably be considered to be B. junceus.^[3]^[4]

Alismatales — Butomaceae — Butomus
Genus Butomus	Flowering rush	N.Y. Status	Images	Distribution	NY NPT
Butomus umbellatus L. 1753. Butomus umbellatus L. 1837. Butomus junceus Turcz.	Flowering rush, Water gladiolus, Grass rush Butome à ombelle, Jonc fleuri	Introduced from Eurasia, northern Africa, Moderately invasive, NYIS: 64%^[1], USGS: L48 invasive, NE-1^[2]		NYFA: X GBIF	USDA-X Go Botany VASCAN ARS-GRIN ITIS FNA Tropicos NatureServe BONAP IPN Images Wikispecies
↑ New York non-native plant invasiveness assessment – Butomus umbellatus: Moderate (64). M.J.Jordan, G.Moore & T.W.Weldy (2008). Invasiveness ranking system for non-native plants of New York. Unpublished. The Nature Conservancy, Albany & Cold Spring Harbor, NY; Brooklyn Botanic Garden, Brooklyn, NY. ↑ Category 1 Plants - highly invasive - Eastern Region invasive plants, ranked by degree of invasiveness as based on information from States (1998) US Forest Service

Family Hydrocharitaceae

The Hydrocharitaceae (tape-grass family) ...

Subfamily Hydrocharitoideae

Hydrocharis

Hydrocharis morsus-ranae

European frog-bit (Hydrocharis morsus-ranae) is a recent invader of northern New York State, often occurring with Phragmites australis.

Alismatales — Hydrocharitaceae — Hydrocharitoideae — Hydrocharis
Genus Hydrocharis	Frog-bit	N.Y. Status	Images	Distribution	NY NPT
Hydrocharis morsus-ranae L. 1753. Hydrocharis Morsus ranae L. 1827. Pontederia dubia Blume 1925. H. dubia (Blume) Backer	Common frogbit, European frog-bit, Frog's bit Hydrocharide grenouillette, Grenouillette, Morène, Petit nénuphar	Introduced from Eurasia, northern Africa, Very highly invasive, NYIS: 86%^[1], Prohibited^[2]		NYFA: X	USDA-XX Go Botany VASCAN ARS-GRIN ITIS FNA Tropicos NatureServe BONAP IPN Images Wikispecies
↑ New York non-native plant invasiveness assessment – Hydrocharis morsus-ranae: Very high (86). M.J.Jordan, G.Moore & T.W.Weldy (2008). Invasiveness ranking system for non-native plants of New York. Unpublished. The Nature Conservancy, Albany & Cold Spring Harbor, NY; Brooklyn Botanic Garden, Brooklyn, NY. ↑ New York State Department of Environmental Conservation Regulation 6 NYCRR Part 575 Prohibited and Regulated Invasive Species

Egeria

Alismatales — Hydrocharitaceae — Hydrocharitoideae — Egeria
Genus Egeria	Waterweed	N.Y. Status	Images	Distribution	NY NPT
Egeria densa Planch. 1849. Egeria densa Planch. 1857. Elodea densa Casp. 1931. Anacharis densa Vict. 1933. Philotria densa Small	Brazilian waterweed, Brazilian elodea, South American waterweed	Introduced from Brazil, Highly invasive, NYIS: 75%^[1], Prohibited^[2], NE-2^[3]		NYFA: X	USDA-XW Go Botany VASCAN ARS-GRIN ITIS FNA Tropicos Images Wikispecies
↑ New York non-native plant invasiveness assessment – Egeria densa: High (75). ↑ New York State Department of Environmental Conservation Regulation 6 NYCRR Part 575 Prohibited and Regulated Invasive Species ↑ Category 2 Plants - moderately invasive - Eastern Region invasive plants, ranked by degree of invasiveness as based on information from States (1998) US Forest Service

Limnobium

Limnobium spongia

Alismatales — Hydrocharitaceae — Hydrocharitoideae — Limnobium
Genus Limnobium Rich. 1814	Spongeplant	N.Y. Status	Images	Distribution	NY NPT
Limnobium spongia (Bosc) Rich. ex Steud. 1807. Hydrocharis spongia Bosc 1814. Limnobium spongia Rich. 1818. Hydrocharis cordifolia Nutt. 1840. Limnobium spongia Steud.	American frogbit, American spongeplant	Introduced, US South native, Impersistent		NYFA: X	USDA-N0 Go Botany-0 ARS-GRIN ITIS FNA Tropicos Images Wikispecies

Subfamily Stratiotoideae

Stratiotes

Stratiotes aloides

Although not yet found in New York, Stratiotes aloides (water soldiers) have been discovered on the Trent River in Ontario and the Ottawa River in Quebec.^[1]^[2]

Alismatales — Hydrocharitaceae — Stratiotoideae — Stratiotes
Genus Stratiotes	Water-aloe	N.Y. Status	Images	Distribution	0 NPT
Stratiotes aloides L. 1753. Stratiotes aloides L.	Water-soldiers, Water-aloe Stratiote faux-aloès, Faux-aloès, Aloès d'eau	Introduced from Eurasia, Highly invasive, NYIS: Not ranked^[1], NYS Tier 1a		no reports iNat	USDA-00 VASCAN ARS-GRIN ITIS Tropicos BONAP Images Wikispecies Note: CA
↑ New York non-native plant invasiveness assessment – Stratiotes aloides: Listed but not ranked (No reports outside of cultivation in New York).

Subfamily Anacharidoideae

Elodea

Alismatales — Hydrocharitaceae — Anacharidoideae — Elodea
Genus Elodea	Waterweed	N.Y. Status	Images	Distribution	NY NPT
Elodea canadensis L.Rich. ex Michx.	Canadian waterweed, Common waterweed, Broad waterweed	Native, Secure		NYFA: 5	USDA-NN Images Wikispecies
Elodea nuttallii (Planch.) St. John	Nuttall's waterweed	Native, Secure		NYFA: 5	USDA-NN Images Wikispecies
Elodea bifoliata H.St.John E. longivaginata H.St.John E. nevadensis (Planch.) H,St.John	Twoleaf waterweed, Two-leaved waterweed, Long-sheath waterweed	Introduced, Western native		NYFA: X	USDA-NN Images Wikispecies

Lagarosiphon

Lagarosiphon major flowers on Salagou Lake, France

African oxygen weed or African elodea (Lagarosiphon major) is listed on the Federal Noxious Weed list and on the Michigan prohibited aquatic plant list.^[1] The New York State rank is High.^[2]

Alismatales — Hydrocharitaceae — Anacharidoideae — Lagarosiphon
Genus Lagarosiphon	Oxygen weed	N.Y. Status	Images	Distribution	NY NPT
Lagarosiphon major (Ridl.) Moss	African oxygen weed, African elodea	Introduced, Highly invasive		NYFA-Excluded	USDA-X? Images Wikispecies

Subfamily Hydrilloideae

Najas

Alismatales — Hydrocharitaceae — Najadoideae — Najadeae — Najas
Genus Najas	Waternymph / Naiad	N.Y. Status	Images	Distribution	NY NPT
Najas flexilis (Willd.) Rostk. & W.L.E.Schmidt 1798. Caulinia flexilis Willd. 1803. Najas canadensis Michx. 1824. N. flexilis Rostk. & W.L.E.Schmidt 1942. N. flexilisssp. caespitosus 1975. N. caespitosus (Maguire) Reveal	Slender naiad, Slender naias, Slender water-nymph, Nodding water-nymph, Bushy naiad, Northern water-nymph, Wavy waternymph	Native, Secure		NYFA: 5	USDA-NN Go Botany ARS-GRIN FNA NatureServe Images Wikispecies
Najas gracillima (A.Braun ex Engelm.) Magnus 1867. Najas indica var. gracillima 1870. Najas gracillima Magnus	Thread-like naiad, Thread-like water-nymph, Slender waternymph	Native, Likely secure		NYFA: 4	USDA-NN Go Botany Images Wikispecies
Najas guadalupensis (Spreng.) Magnus ssp. guadalupensis 1825. Caulinia guadalupensis Spreng. 1870. Najas guadalupensis Magnus	Southern water-nymph, Southern naiad	Native, Secure		NYFA: 5	USDA-NN Go Botany ARS-GRIN ITIS FNA Tropicos Images Wikispecies
Najas guadalupensis (Spreng.) Magnus ssp. muenscheri (R.T.Clausen) R.R.Haynes & Hellq. 1937. Najas muenscheri R.T.Clausen 1979. N.g.var. muenscheri 1996. N.g.ssp. muenscheri	Hudson River water-nymph, Muenscher's water-nymph, Mermaid weed	Native, Endangered, NYNHP: 1 Endemic^[1]		NYFA: 1E	USDA-N0 ITIS FNA Tropicos Images Wikispecies
Najas guadalupensis (Spreng.) Magnus ssp. olivacea (Rosend. & Butters) R.R.Haynes & Hellq. 1935. N. olivacea Rosend.& Butters 1979. N. guadalupensisvar. olivacea 1996. N. guadalupensisssp. olivacea	Guadalupe water-nymph, Southern naiad	Native, Endangered		NYFA: 1	USDA-NN Go Botany FNA Tropicos Images Wikispecies
Najas marina L. 1753. Najas marina L. 1893. Najas gracilis Morong 1903. Najas gracilis Small	Spiny water-nymph, Spiny naiad, Holly-leaved naiad, Prickly waternymph	Native, Endangered		NYFA: 1	USDA-NN ARS-GRIN FNA Tropicos Images Wikispecies
Najas minor All. 1773. Najas minor All. 1807. Fluvialis minor Pers. 1808. Ittnera minor C.C.Gmel. 1845. Caulinia minor Coss. & Germ.	Brittle water-nymph	Introduced from Eurasia, n. Africa, Moderately invasive, NYS Tier 5^[2], ^[3]		NYFA: X	USDA-XX Go Botany ARS-GRIN FNA Tropicos Images Wikispecies
↑ The Hudson River water-nymph is endemic to the lower Hudson River (from the Mohawk River to Piermont), one of the few New York endemic taxa. New York Natural Heritage Program. 2024. Online Conservation Guide for Najas guadalupensis ssp. muenscheri. Endangered, S1/G5T1. ↑ New York State Invasive Species Tiers: Najas minor (brittle naiad) - NYS Tier 5 ↑ Najas minor is prohibited in Connecticut, Maine, Massachusetts, and New Hampshire. 2021 Native Plant Trust, Go Botany.

Hydrilla

Hydrilla verticillata

The genus Hydrilla is usually considered to contain the single species Hydrilla verticillata, which is commonly known simply as hydrilla. It's a Eurasian aquatic plant commonly used in aquariums and was probably first released in North America in the 1950s but not found in New York State until 2008, when it was discovered in Orange and Suffolk Counties.^[1]^[2]

More recently, hydrilla has been discovered in and around Cayuga Lake, Tonawanda Creek near Buffalo, Susquehanna River near Binghamton and elsewhere. By 2021, iMapInvasives showed hydrilla in at least 12 New York counties.^[3]

Alismatales — Hydrocharitaceae — Najadoideae — Najadeae — Hydrilla
Genus Hydrilla	Water-thyme	N.Y. Status	Images	Distribution	NY NPT
Hydrilla verticillata (L.f.) Royle 1782. Serpicula verticillata L.f. 1824. Udora verticillata Spreng. 1839. Hydrilla verticillata Royle 1888. Elodea verticillata F.Muell.	Hydrilla, Florida elodea, Waterthyme, Water-thyme, Esthwaite waterweed	Introduced from Eurasia, Africa, Australia, Very highly invasive, NYIS: 91%^[1], NYS Tier 2^[2], Discovered 2008.^[3]		NYFA: Orange, Westchester iMap: ≥ 12 counties NYFA: X1	USDA-X0 Go Botany ARS-GRIN ITIS FNA Tropicos Images Wikispecies
↑ New York non-native plant invasiveness assessment – Hydrilla verticillata: Very high (91). ↑ New York State Invasive Species Tiers: Hydrilla verticillata. 2021 New York Natural Heritage Program. ↑ Three large infestations of Hydrilla were discovered in Orange and Suffolk Counties in 2008.

Vallisneria

Alismatales — Hydrocharitaceae — Najadoideae — Vallisnerieae
Genus Vallisneria	Eelgrass	N.Y. Status	Images	Distribution	NY NPT
Vallisneria americana Michx.	Eel-grass, Tape-grass, Water-celery, Wild-celery	Native, Secure		NYFA: 5	USDA-NN Images Wikispecies

Family Scheuchzeriaceae

The monotypic Scheuchzeriaceae (scheuchzeria family)

Scheuchzeria

Alismatales — Scheuchzeriaceae — Scheuchzeria
Genus Scheuchzeria	Rannoch-rush	N.Y. Status	Images	Distribution	NY NPT
Scheuchzeria palustris L. S. americana (Fernald) G.N.Jones S. palustrisvar. americana Fernald	American scheuchzeria, Rannoch-rush	Native, Vulnerable		NYFA: 3	USDA-NN Go Botany Images Wikispecies

Family Juncaginaceae

The Juncaginaceae (arrowgrass family)

Triglochin

Alismatales — Juncaginaceae — Triglochin
Genus Triglochin	Arrowgrass	N.Y. Status	Images	Distribution	NY NPT
Triglochin maritima L.	Seaside arrowgrass	Native, Likely secure		NYFA: 4	USDA-NN Images Wikispecies
Triglochin palustris L.	Slender bog arrow-grass	Native, Threatened		NYFA: 2	USDA-NN Images Wikispecies

Family Ruppiaceae

The Ruppiaceae (ditch-grass family)

Ruppia

Ruppia maritima
ditch-grass

Alismatales — Ruppiaceae — Ruppia
Genus Ruppia	Widgeonweed	N.Y. Status	Images	Distribution	NY NPT
Ruppia maritima L. 1753. Ruppia maritima L. 1915. Buccaferrea maritima Lunell	Ditch-grass, Beaked ditchgrass, Widgeongrass, Sea ditchgrass, Tassel pondweed Ruppie maritime, Persil d'eau	Native, Vulnerable OBL Perennial, Herb-forb		NYFA: 3-4	USDA-NN Go Botany VASCAN ITIS FNA Tropicos NatureServe BONAP Images Wikispecies

Family Zosteraceae

The Zosteraceae (eelgrass family)

Zostera

Alismatales — Zosteraceae — Zostera
Genus Zostera	Eelgrass	N.Y. Status	Images	Distribution	NY NPT
Zostera marina L. (1753) Zostera pacifica L.	Eelgrass, Seawrack, Zostére marine	Native, Vulnerable		NYFA: 3	USDA-NN ITIS FNA Images Wikispecies

Family Potamogetonaceae

The Potamogetonaceae (pond-weed family)

Tribe Potamogetoneae

Potamogeton

The Potamogeton (pondweed) subdivisions used here are from Lindqvist et al. (2006).^[1] Chromosome numbers are from Kaplan et al. (2013).^[2]

Potamogeton clade 1A

Potamogeton crispus
curly-leaved pondweed

Alismatales — Potamogetonaceae — Potamogeton — clade 1A
Genus Potamogeton clade 1A	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton robbinsii Oakes	Robbins' pondweed, Flat-leaved pondweed, Fern pondweed Potamot de Robbins	Native, Secure, 2n = 52		NYFA: 5	USDA-NN Go Botany FNA Images Wikispecies
Potamogeton crispus L. 1753. Potamogeton crispus L.	Curly pondweed, Curled pondweed Potamot crepu	Introduced from Eurasia, northern Africa, Australia, Very highly invasive, NYIS: 80%^[1], NE-1^[2] Note^[3], 2n = 52		NYFA: X	USDA-XX Go Botany ARS-GRIN FNA Images Wikispecies
↑ New York non-native plant invasiveness assessment – Potamogeton crispus: Very high (80). ↑ Category 1 Plants - highly invasive - Eastern Region invasive plants, ranked by degree of invasiveness as based on information from States (1998) US Forest Service ↑ The exotic invasive Potamogeton crispus is easily recognized by being the only species in North America with serrate leaves (Flora of North America).

Potamogeton clade 1B

Potamogeton natans

Alismatales — Potamogetonaceae — Potamogeton — clade 1B
Genus Potamogeton clade 1B	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton natans L.	Floating pondweed, Floating-leaved pondweed	Native, CoC: 4, Secure OBL Perennial, Herb-forb, 2n = 52		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton nodosus Poir. 1816. Potamogeton nodosus Poir. 1848. P. lonchites Tuck. 1893. P. americanus var. novaeboracensis (Morong) A. Benn. ex Fassett 1893. P. lonchites var. novaeboracensis Morong	Long-leaved pondweed	Native, CoC: 4, Secure OBL Perennial, Herb-forb, 2n = 52		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton perfoliatus L. 1753. P. perfoliatus L.	Claspingleaf pondweed, Clasping-leaved pondweed, Clasped pondweed, Perfoliate pondweed Potamot perfolié	Native, CoC: 5, Secure OBL Perennial, Herb-forb, 2n = 52		NYFA: 5	USDA-NN Go Botany ARS-GRIN FNA Images Wikispecies
Potamogeton richardsonii (A.Benn.) Rydb. 1889. P. perfoliatus var. richardsonii A.Benn. 1905. P. richardsonii Rydb. 1941. P. perfoliatus ssp. richardsonii Hultén	Richardson's pondweed	Native, CoC: 6, Secure OBL Perennial, Herb-forb, 2n = 52		NYFA: 5	USDA-NN Go Botany FNA Images Wikispecies
Potamogeton amplifolius Tuck. (1848)	Largeleaf pondweed, Large-leaved pondweed, Broad-leaved pondweed Potamot à grandes feuilles	Native, CoC: 7, Secure OBL Perennial, Herb-forb, 2n = 52		NYFA: 5	USDA-NN Go Botany VASCAN FNA Images Wikispecies
Potamogeton oakesianus J.W.Robbins	Oakes' pondweed	Native, CoC: 7, Secure OBL Perennial, Herb-forb, Chro. # unk.		NYFA: 5	USDA-NN Go Botany FNA Images Wikispecies
Potamogeton praelongus Wulfen	Whitestem pondweed, White-stemmed pondweed Potamot à longs pédoncules	Native, CoC: 7, Secure OBL Perennial, Herb-forb, 2n = 52		NYFA: 5	USDA-NN Go Botany FNA Images Wikispecies
Potamogeton gramineus L.	Grassy pondweed	Native, CoC: 7, Secure OBL Perennial, Herb-forb, n = 26		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton illinoensis	Illinois pondweed	Native, CoC: 7, Secure OBL Perennial, Herb-forb, 2n = 104		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton × spathuliformis (J.W. Robbins) Morong (pro sp.) Potamogeton gramineus × Potamogeton illinoensis	Hybrid pondweed	Native, Vulnerable OBL Perennial, Herb-forb, 2n = 78		NYFA: 3?	USDA-NN Images Wikispecies
Potamogeton × nitens Potamogeton gramineus × Potamogeton perfoliatus	Hybrid pondweed	Native, Vulnerable OBL ?, Herb-forb, 2n = 52		NYFA: 3?	USDA-NN Images Wikispecies
Potamogeton × subdentatus Hagstr. Potamogeton illinoensis × Potamogeton perfoliatus	Hybrid pondweed	Native, Unranked OBL ?, Herb-forb		NYFA: U	USDA-N0 Images Wikispecies
Potamogeton alpinus Balbis	Alpine pondweed, Northern pondweed, Red pondweed	Native, CoC: 9, Threatened OBL Perennial, Herb-forb, 2n = 52		NYFA: 2	USDA-NN Go Botany FNA Images Wikispecies
Potamogeton pulcher Tuck.	Spotted pondweed	Native, CoC: 10, Threatened OBL Perennial, Herb-forb, chr. # unk.		NYFA: 2	USDA-NN Go Botany Images Wikispecies
Genus Potamogeton clade 1B (excluded species)	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton lucens	Shining pondweed	Introduced from Eurasia, northern Africa, N.Y. excluded OBL, 2n = 52		NYFA-Excluded	Images Wikispecies
Potamogeton × angustifolius Potamogeton gramineus × Potamogeton lucens	Long-leaved pondweed	Introduced from Eurasia, northern Africa, N.Y. excluded OBL, 2n = 52		NYFA-Excluded	Images Wikispecies

Potamogeton clade 2A

Alismatales — Potamogetonaceae — Potamogeton — clade 2A
Genus Potamogeton clade 2A	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton epihydrus Raf. 1808. Potamogeton epihydrus Raf. 1827. P. nuttallii Cham. & Schltdl. 1894. P. nuttallii var. ramosus Peck 1924. P. epihydrus var. ramosus (Peck) House 1932. P. epihydrus var. typicus (Raf.) Fernald (i) 1932. P. epihydrus var. nuttallii (Cham. & Schltdl.) Fernald 1965. P. epihydrus ssp. nuttallii (Cham. & Schltdl.) Calder & Roy L.Taylor	Ribbon-leaved pondweed, Nuttall's pondweed	Native, CoC: 6, Secure OBL Perennial, Herb-forb, 2n = 26		NYFA: 5	USDA-NN Go Botany FNA Tropicos Images Wikispecies

Potamogeton clade 2B

Alismatales — Potamogetonaceae — Potamogeton — clade 2B
Genus Potamogeton clade 2B	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton spirillus Tuck. 1817. P. dimorphus Raf. 1848. P. spirillus Tuck.	Spiral pondweed, Northern snailseed pondweed Potamot spirille	Native, CoC: 7, Secure OBL Perennial, Herb-forb, 2n = 28		NYFA: 5	USDA-NN Go Botany VASCAN FNA Tropicos Images Wikispecies
Potamogeton bicupulatus Fernald 1893. P. diversifolius var. trichophyllus Morong 1932. P. bicupulatus Fernald	Snailseed pondweed, Snail-seeded pondweed	Native, CoC: 8, Secure OBL Perennial, Herb-forb		NYFA: 5	USDA-NN Go Botany VASCAN FNA Tropicos Images Wikispecies
Potamogeton confervoides Rchb. 1845. P. confervoides Rchb. P. tuckermanii	Algae-like pondweed, Alga pondweed, Tuckerman’s pondweed Potamot confervoïde	Native, CoC: 9, Threatened OBL Perennial, Herb-forb		NYFA: 3	USDA-NN Go Botany VASCAN Images Wikispecies
Potamogeton diversifolius Raf. (1808) P. capillaceus Poir. P. dimorphus Raf.	Water-thread pondweed	Native, CoC: 10, Endangered OBL Perennial, Herb-forb, 2n = 28		NYFA: 1	USDA-N0 Go Botany FNA Images Wikispecies

Potamogeton clade 2C

Alismatales — Potamogetonaceae — Potamogeton — clade 2C
Genus Potamogeton clade 2C	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton foliosus Raf. ssp. foliosus	Leafy pondweed	Native, Secure		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton pusillus L.	Small pondweed	Native, Secure		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton berchtoldii Fieber Potamogeton berchtoldii Fieber Potamogeton pusillus var. tenuissimus Mert. & W.D.J.Koch Potamogeton pusillus ssp. tenuissimus (Mert. & W.D.J.Koch) Haynes & C.B.Hellquist	Berchtold’s pondweed	Native, CoC: 2, Secure, Herb-forb		NYFA: 5	Go Botany Images Wikispecies
Potamogeton vaseyi J.W.Robbins 1867. Potamogeton vaseyi J.W.Robbins	Vasey's pondweed	Native, Secure		NYFA: 5	USDA-NN Go Botany FNA Images Wikispecies
Potamogeton zosteriformis Fernald auct. Potamogeton compressus non L.	Flat-stemmed pondweed, Flatstem pondweed	Native, Secure		NYFA: 5	USDA-NN Go Botany Images Wikispecies
Potamogeton friesii	Fries' pondweed	Native, Likely secure		NYFA: 4?	USDA-NN Go Botany Images Wikispecies
Potamogeton obtusifolius Mert. & W.D.J. Koch	Blunt-leaved pondweed	Native, Likely secure		NYFA: 4	USDA-NN Go Botany Images Wikispecies
Potamogeton hillii Morong	Hill's pondweed	Native, Threatened		NYFA: 2	USDA-NN Go Botany Images Wikispecies
Potamogeton ogdenii Hellquist & Hilton	Ogden's pondweed	Native, Endangered		NYFA: 1	USDA-NN Go Botany Images Wikispecies
Potamogeton strictifolius Benn. auct. P. rutilus non Wolfg.	Straight-leaved pondweed, Narrowleaf pondweed	Native, Endangered		NYFA: 1	USDA-NN Go Botany Images Wikispecies
Potamogeton × haynesii Hellquist & Crow Potamogeton strictifolius × Potamogeton zosteriformis	Hybrid pondweed	Native, Endangered		NYFA: 1?	USDA-NN Images Wikispecies
Genus Potamogeton clade 2C (excluded species)	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Potamogeton compressus 1753. P. compressus L.	Grass-wrack pondweed, Flatstem pondweed, Eelgrass pondweed	Introduced from Eurasia, N.Y. excluded		NYFA-Excluded	Kew WCSP Images Wikispecies
Potamogeton rutilus Wolfg. 1827. P. rutilus Wolfg.	Shetland pondweed	Introduced from Eurasia, N.Y. excluded		NYFA-Excluded	Kew WCSP Images Wikispecies

Stuckenia

Alismatales — Potamogetonaceae — Stuckenia
Genus Stuckenia	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Stuckenia pectinata (L.) Börner Potamogeton pectinatus L. Stuckenia pectinata (L.) Börner Coleogeton pectinatum (L.) Les & R.R.Haynes	Sago pondweed	Native, CoC: 2, Secure		NYFA: 5	USDA-NN Images Wikispecies
Stuckenia filiformis (Pers.) Börner	Thread-leaved pondweed, Fineleaf pondweed	Native, Endangered		NYFA: 1	USDA-NN Images Wikispecies
Genus Stuckenia (excluded species)	Pondweed	N.Y. Status	Images	Distribution	NY NPT
Stuckenia vaginata (Turcz.) Holub 1854. Potamogeton vaginatus Turcz. 1984. Stuckenia vaginata (Turcz.) Holub	Sheathed pondweed, Big sheathed pondweed, Large sheathed pondweed Potamot engainé	N. America native, Endangered		NYFA-Excluded	USDA-NN FNA Images Wikispecies

Tribe Zannichellieae

Zannichellia

Alismatales — Potamogetonaceae — Zannichellia
Genus Zannichellia	Horned pondweed	N.Y. Status	Images	Distribution	NY NPT
Zannichellia palustris L. 1753. Zannichellia palustris L.	Horned pondweed	Native, Secure		NYFA: 5	USDA-NN Go Botany VASCAN ITIS FNA Images Wikispecies

[1] Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 14, July 2017 (and more or less continuously updated since).

[2] P. F. Stevens, (2001 onwards). "Acorales," Angiosperm Phylogeny Website. Version 13, September 28, 2013 (and more or less continuously updated since). http://www.mobot.org/MOBOT/research/APweb/orders/Acoralesweb.htm#Acorales.

[3] P. F. Stevens, (2001 onwards). "Alismatales," Angiosperm Phylogeny Website. Version 13, September 28, 2013 (and more or less continuously updated since). http://www.mobot.org/MOBOT/research/APweb/orders/Alismatalesweb.htm#Alismatales.

[4] New York Natural Heritage Program. 2024. Online Conservation Guide for Orontium aquaticum. Threatened, S2/G5.

[5] "The initial ρ of a Greek word transliterated as rh, e.g. rhiza (ριζα, root, rhizome), should have an additional r added to it when preceded by a vowel, e.g. Glycyrrhiza (γλυκυρριζα, liquorice, from γλυκος, sweet, ριζα, root), leptorrhiza (λεπτορριζα, with a thin root, from λεπτος, small, slender), but as many reputable authors, Linnaeus among them, have omitted this additional r, it is best regarded as optional and an author's original spelling, as in Lemna polyrhiza, should be accepted." - W. T. Stearn (1992), Botanical Latin ed. 4: 261.

[6] New York Natural Heritage Program. 2024. Online Conservation Guide for Lemna perpusilla. Endangered, S1/G5.

[7] New York Natural Heritage Program. 2024. Online Conservation Guide for Lemna valdiviana. Endangered, S1/G5.

[8] M. Treiber (1980). "Biosystematics of the Arisaema triphyllum Complex." PhD Dissertation, University of North Carolina, Chapel Hill.

[renner-9] Susanne S. Renner, Li-Bing Zhang & Jin Murata (2004) "A chloroplast phylogeny of Arisaema (Araceae) illustrates Tertiary floristic links between Asia, North America, and East Africa." American Journal of Botany 91(6): 881-888.

[10] New York Species Record for Pinellia ternata (crowdipper) in iMapInvasives, updated 8/8/2016

[11] New York State Invasive Species Tiers, Water lettuce (Pistia stratiotes).

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Flora of New York/Acorales & Alismatales