222 Minnesota Plant Life. 



may be several feet in length, coming up like a wire from the 

 bottom of the pool and bearing the little head at the surface of 

 the water. The name pipezvort is given on account of the hol- 

 low stem which bears the flowering head. 



Blue-eyed-Marys. The spiderwort family includes two Min- 

 nesota species, the common spiderworts or blue-eyed-]Marys 

 frequent on banks, along roadsides and railway tracks and at 

 the edges of meadows. The plants are mucilaginous and when 

 broken excrete a viscid slime. The leaves are rather thick, 

 grass-like in form, and arise from a simple or branched stem. 

 The flowers are produced in generally terminal umbels and are 

 of a bluish-purple color an inch or so in diameter. There are 

 three purple petals and three green calyx leaves below. There 

 are three carpels fused together to form the fruit rudiment, sur- 

 rounded by six stamens. When the ovoid fruit is mature it 

 splits by three longitudinal lines equi-distant from each other, 

 as does also the iris fruit. The stamens in these plants possess 

 tufts of interesting purple hairs which are very beautiful objects 

 for microscopic study. 



Pickerel-weeds. A somewhat common green-house member 

 of the pickerel-weed family is known as the water-hyacinth and 

 is similar in its flowering clusters to the rather rare native pick- 

 erel-weed of Minnesota. Any one who has seen the flowers of 

 the water-hyacinth will recognize the pickerel-weed if he 

 chances upon it at the edges of a marsh or in tamarack swamp. 

 The leaves are thick, shaped somewhat like those of the arrow- 

 head, and arise from a prostrate rootstock. The flowering stem 

 stands erect, bearing one large heart-shaped leaf, with some 

 sheathing bracts at the base. The whole flowering stem varies 

 from one to four feet in height, while the large leaf may be 

 ordinarily as much as six inches long. The flowers are pale 

 blue and delicate in texture like the flowers of the water-hya- 

 cinth. They occur in clusters on a somewhat fleshy spike at 

 the base of which is a small thin spathe. 



Water star-grasses. Related to the pickerel-weed and a 

 member of its family is a little mud-fiat plant known as the 

 water star-grass. When growing in water the stem of this 

 plant is two or three feet in length, no thicker tlian a knitting- 



