322 MORPHO LOGY. 



the flower of trillium sometimes presents. In fig. 381 is a sketch 

 of a flower of trillium, made from a photograph. One set of 

 the stamens has expanded into petal-like organs, with the anther 

 sacs on the margin. In fig. 380 is shown a plant of Trillium 

 grandiflorum in which the pistil has separated into three distinct 

 and expanded leaf-like structures, all green except portions of 

 the margin. 



Dentaria. 



646. General appearance. For another study we may take 

 a plant which belongs to another division of the higher plants, 

 the common "pepper root," or " toothwort " (Dentaria 

 diphylla) as it is sometimes called. This plant occurs in moist 

 woods during the month of May, and is well distributed in the 

 northeastern United States. A plant is shown in fig. 383. It 

 has a creeping underground rhizome, whitish in color, fleshy, 

 and with a few scales. Each spring the annual flower-bearing 

 stem rises from one of the buds of the rhizome, and after the 

 ripening of the seeds, dies down. 



The leaves are situated a little above the middle point of the 

 stem. They are opposite and the number is two, each one 

 being divided into three dentate lobes, making what is called a 

 compound leaf. 



647. Parts of the flower. The flowers are several, and they 

 are borne on quite long stalks (pedicels) scattered over the ter- 

 minal portion of the stem. We should now examine the parts 

 of the flower beginning with the calyx. This we can see, look- 

 ing at the under side of some of the flowers, possesses four scale- 

 like sepals, which easily fall away after the opening of the flower. 

 They do not resemble leaves so much as the sepals of trillium, 

 but they belong to the leaf series, and there are two pairs in the 

 set of four. The corolla also possesses four petals, which are more 

 expanded than the sepals and are whitish in color. The sta- 

 mens are six in number, one pair lower than the others, and also 



