22 AMERICAN ROOT DRUGS. 



which the false root was derived was found upon investigation to l)e almost 

 identical with the true yam, except that the leaves were perfectly smooth, lack- 

 ing the hairiness on the under surface of the leaf which is characteristic of 

 the true wild yam. The false variety also differs in its habit of growth, not 

 growing in dense clumps like the true wild yam, but generally isolated. The 

 root of the variety, however, is quite distinct from that of the true wild yam, 

 being much more knotty. Lloyd states further that the hairiness or lack of 

 hairiness on the under side of the leaf is a certain indication as to the form 

 of the root. 



Lloyd, recognizing the necessity of classifying these two yam roots of com- 

 merce, has designated the smooth-leaved variety as Dloscorea villosa var. 

 glabra. 



Description of rootstocks. — The rootstock of the true wild yam (PL II, fig. 3) 

 runs horizontally underneath the surface of the ground. As found in commerce, 

 it consists of very hard pieces, (5 inches and sometimes 2 feet in length, but 

 only about one-fourth or one-half of an inch in diameter, twisted, covered with a 

 thin In-own bark, whitish within, and showing stem scars almost an inch apart 

 on the upper surface, small protuberances on the sides, and numerous rather 

 wiry rootlets on the lower surface. 



The false wild yam, on the other hand, has a much heavier, rough, knotty 

 rootstock, with thick branches from 1 incli to :! inches long, the upper surface 

 covered with crowded stem scars and the lower side furnished with stout wiry 

 rootlets. Within it is similar to the true yam root. 



Collect io)i, prices, and uses. — The roots are generally .collected in autumn, 

 and bring from 2J to 4 cents a pound. Wild yam is said to possess expectorant 

 properties and to promote perspiration, and in large doses proving emetic. It 

 has been employed in bilious colic, and by the negroes in the South in the 

 treatment of muscular rheumatism. 



BLUE FLAG. 

 Iris versicolor L. 



Other common names. — Iris, flag-lily, liver-lily, snake-lily, poison-flag, water- 

 flag, American fleur-.de-lis or flower-de-luce. 



Habitat and range. — Blue flag delights in wet. swampy localities, making its 

 home in marshes, thickets, and wet meadows from Newfoundland to Manitoba, 

 south to Florida and Arkansas. 



Description of plant. — The flowers of all of the species belonging to this 

 genus are similar, and are readily recognized by their rather peculiar form, the 

 three outer segments or parts reflexed or turned back and the three inner seg- 

 ments standing erect. 



Blue flag is about 2 to 3 feet in height, with an erect stem sometimes branched 

 near the top, and sword-shaped leaves which are shorter than the stem, fi'om 

 one-half to 1 inch in width, showing a slight grayish " bloom," and sheathing 

 at the base. This plant is a perennial belonging to the iris family (Iridaceae), 

 and is a native of this country. June is generally regarded as the month for 

 the flowering of the blue flag, although it may be said to be in flower from May 

 to July, depending on the locality. The flowers are large and very handsome, 

 each stem bearing from two to six or more. They consist of six segments or 

 parts, the three outer ones turned back and the three inner ones erect and 

 much smaller. (Tl. II, fig. 4.) The flowers are usually purplish blue, the 

 " claw," or narrow base of the segments, variegated with yellow, green, or 

 white and marked with purple veins. 

 107 



