Minnesota Plant Life. 219 



round and solid bodies. In a week or so after such a bulb has 

 been formed, if sought where it first appeared, it cannot be 

 found, for by this time it will have burrowed to the bottom of 

 the pot. In this manner the erect rootstocks of skunk-cab- 

 bages sink a foot or two into the soil as any one who attempts 

 to dig up a perfect plant will soon discover. The way that this 

 is accomplished is by the development of contractile roots on 

 the young nodes. Four or five of these roots are sent obliquely 

 down into the soil on different sides of the stem. When they 

 are long enough they produce some short lateral branches near 

 their tips, thus anchoring themselves. They then contract and 

 the bulb or stem the base of which may be sharply pointed 

 is pulled down into the earth. By this means the plant estab- 

 lishes its stems sometimes twenty inches below the point where 

 they began to form. The contractile roots, differing consid- 

 erably from the ordinary absorptive roots, may be recognized 

 by their large size and by the wrinkles on their surface. 



Although the berries of most of the arums are exceedingly 

 unpleasant to the taste, some birds seem to fancy them and their 

 bright red color in the jack-in-the-pulpit, calla and skunk-cab- 

 bage is no doubt in the nature of an advertisement to attract 

 the attention of such as will eat them. 



All of these plants except the sweet-flag grow in rich soil, in 

 deep woods, ravines or swamp borders. Like most shade- 

 loving plants, they have large leaves of thin texture. The jack- 

 in-the-pulpit is a typical shade plant in structure. Unlike most 

 of its class, its leaves are netted veined and the broad, thin blades 

 are fitted to catch as much sunlight as possible. The flowers 

 in this plant are commonly of two kinds. The staminate may 

 occur either upon the same fleshy axis with the pistillate, and 

 just above them, or upon a separate axis. The peculiar club- 

 shaped elongation of the flowering axis in the jack-in-the-pulpit 

 is not characteristic of the calla, the skunk cabbage or the sweet 

 flag, for in the latter plants the flowers cover the axes to their 

 tips. The sweet-flag occupies a different habitat from the oth- 

 ers preferring the edges of streams and swamps. Its rootstocks 

 are used in pharmacy and are often collected and chewed by 

 children, for they have not the acrid taste and are harmless. 

 The leaves of the sweet-flag are similar to those of the blue flag 



