common water hemlock

(Cicuta maculata var. maculata)

               
Conservation Status

IUCN Red List

not yet assessed

common water hemlock

NatureServe

N5 - Secure

SNR - Unranked

Minnesota

not listed

Wetland
Indicator
Status

Great Plains

OBL - Obligate wetland

Midwest

OBL - Obligate wetland

Northcentral & Northeast

OBL - Obligate wetland

Nativity

Native

Photo by Luciearl
Occurrence

Very common

 
Habitat

Wet to moderate moisture. Meadows, woods, marshes.

Flowering

June to August

 
Flower Color

White

     
Height

2 to 7

     

Identification

This is a 2 to 7 tall, erect, perennial forb that rises on one or more stems from several fleshy, tuberous roots. The foliage has a foul smell.

The stems are erect, unbranched or branched at the top, stout, hairless, hollow, and often covered with a whitish, waxy bloom (glaucous). They may be green or purple. Mature stems are green with purple spots or stripes. The base of the stem is enlarged.

The main stem leaves are alternate and are divided into 3 segments (ternate). Each segment may be again divided into 3 sections (biternate). Each ultimate section is divided into usually 3, sometimes 5 leaflets (pinnate). The lower leaves are up to 18 long and 8 wide, becoming progressively much smaller as they ascend the stem. The uppermost leaves are sometimes undivided. The leaves are on 4 to 12 long leaf stalks, longest near the bottom of the stem, shorter near the top. The leaf stalks form a sheath at the base that wraps around the stem. The leaf nodes are purplish.

The leaflets are narrowly lance-shaped, 1 to 5 long, ¼ to 1½ wide, and hairless. They are often folded upward along the main vein. The margins have sharp, forward-pointing teeth. The leaflet nodes are purplish. The radial veins of the leaflet extend to the notches between the teeth, not to the tips of the teeth as in other members of the carrot family. The main leaflets of the middle and upper leaves are less than 5 times as long as wide.

The inflorescence is a compound umbel at the end of the stem and each branch. The umbels are round and 1½ to 5 in diameter. They are composed of 10 to 20 umbellets. They are not subtended by bracts.

The umbellets are on stalks (rays) 2 to 2 long. Each one has 14 to 27 individual flowers on stalks (raylets) up to 1 long.

The flowers are about wide with 5 white, rounded, erect to spreading petals and 5 white stamens. The petals are notched at the tip.

The fruit is dry, dark brown to reddish-brown, 1 16 to long, broadly oblong-eliptic, and flattened laterally. It contains 2 seeds and when ripe splits into 2 one-seeded segments. Each segment (mericarp) has 5 ribs: an upper (dorsal) rib; two lateral ribs; and between each lateral rib and the dorsal rib, an intermediate rib. The ribs are blunt and somewhat corky. The dorsal and intermediate ribs are smaller than the lateral ribs and are as wide or wider than the space between the ribs. The lateral ribs are smaller than the oil tube.

The seeds are flattened on one side, rounded on the other.

 
Similar
Species

In water hemlocks the radial veins of the leaflet extend to the notches in the leaflet, not to the tips as in other members of the carrot family.

Bolander’s water hemlock (Cicuta maculata var. bolanderi) mericarp dorsal and intermediate ribs are much narrower than the space between the ribs. The lateral ribs are larger than the oil tube.

Bulbet-bearing water hemlock (Cicuta bulbifera) has bulbils at the leaf axils of some of the upper leaves.

Spotted water hemlock (Cicuta maculata var. angustifolia) main leaflets of the middle and upper leaves are narrower, more than 5 times as long as wide. The fruit is almost globe-shaped, not oblong.


Distribution Distribution Map  

Sources: 4, 7, 24, 28.


Comments

Very Common…
Of the three varieties of Cicuta maculata found in Minnesota, var. maculata is by far the most common, according to the Minnesota Biodiversity Atlas. It has been recorded in 81 of the 87 counties in the state.

…and Very Poisonous
Spotted water hemlock is the most poisonous plant in Minnesota and may be the most poisonous plant in all of North America. All parts of the plants are toxic, but the tuberous roots, swollen lower stems, and all new growth are especially toxic.


Taxonomy

Family:

Apiaceae (carrot)

 

Subfamily:

Apioideae

 

Tribe:

Oenantheae

 
Parent

spotted water hemlock (Cicuta maculata)

 
Synonyms

Cicuta curtissii

Cicuta maculata var. curtissii

Cicuta mexicana

 
Common
Names

common water hemlock

musquash-root

poison parsnip

spotted cowbane

spotted parsley

spotted water hemlock

spotted waterhemlock

spotted water-hemlock

water-hemlock


 

 

 

 

 

 

 

Glossary

Biternate

Twice ternate. A leaf divided into 3 segments, with each segment divided into 3 leaflets.

 

Bract

Modified leaf at the base of a flower stalk or flower cluster.

 

Compound leaf

A leaf that is divided into leaflets, each leaflet having the general appearance of a leaf, with all leaflets attached to a single leaf stem.

 

Glaucous

Pale green or bluish gray due to a whitish, powdery or waxy film, as on a plum or a grape.

 

Mericarp

The split, usually one-seeded portion of a dry, multi-seeded fruit.

 

Node

The small swelling of the stem from which one or more leaves, branches, or buds originate.

 

Palmate

Similar to a hand. Having more than three lobes or leaflets that radiate from a single point at the base of the leaf.

 

Pinnate

Having the leaflets of a compound leaf arranged on opposite sides of a common stalk.

 

Sheath

The lower part of the leaf that surrounds the stem.

 

Ternate

Refers to leaves that are divided into three leaflets or sections.

 

Umbel

A flat-topped or convex, umbrella-shaped cluster of flowers or buds arising from more or less a single point.

 

Umbellet

A secondary umbel in a compound umbel.

       

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  water hemlock / spotted water hemlock (Cicuta maculata syn. C. curtissii, C. mexicana)
UFInvasivePlantsEDU
 
   
 
About

Uploaded on May 20, 2010

Aquatic and Invasive Plant Identification Series by the UF/IFAS Center for Aquatic and Invasive Plants ( http://plants.ifas.ufl.edu ) and the Florida Fish and Wildlife Commission, Invasive Plant Management Section.

For more information about water hemlock, go to http://plants.ifas.ufl.edu/node/99

Video editor/videographer - Phil Chiocchio

 
     

 

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Luciearl
7/23/2019

Location: Cass County

common water hemlock


     
     
 

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