178 



So far as their occurrence in Alaska is concerned, the species 

 are very distinct and can be readily separated by vegetative char- 

 acters alone. Cicuta douglasii and Ciciifa niacidata grow up to 

 2 meters tall and Cicuta mackensieana up to 1^^ meters. All have 

 bipinnate leaves which often appear to be ternate-pinnate. In 

 C. douglasii the leaflets are lanceolate, 1-5 cm. wide X 2^-9 cm. 

 long, serrate to doubly serrate or even incised and with sharp 

 teeth. In C. maculata the leaflets are more narrowly lanceolate, 

 .8-3 cm. X 3-9 cm., rather evenly serrate with sharp, mostly out- 

 ward pointed teeth. The leaflets of C. mackensieana are narrowly 

 lanceolate to linear, .2-2 cm. X 2-10 cm., with rather remote, 

 sharp, forward-pointing teeth, these being rather small on the 

 more narrow leaflets. Fruits of C. douglasii are deeply grooved, 

 about 2% mm. long and wide. C. mackensieana also has deeply 

 grooved fruits which are about 2j4' mm. wide X 2 mm. long. In 

 C. maculata the fruit is not grooved, the space being filled by thick 

 corky ribs. The fruit measures about 2^ mm. wide X 3^4 mm. 

 long. All the species are found growing in shallow water, some- 

 times ascending into mud, but never in well drained situations. 

 This habitat is quite different from that of other tall growing 

 members of the same family, which are always found on better 

 drained soils. 



Literature Cited 



Mathias, Mildred E. & Lincoln Constance. 1942. A synopsis of the Ameri- 

 can species of Cicuta. Madrono 6: 145-151. PI. 14. 

 Porsild, A. E. 1939. Contributions to the flora of Alaska. Rhodora 41: 266. 



Botany Department 

 Iowa State College 

 Ames, Iowa 



