6i 



young plant. The hypocotyl now begins to be bent towards 

 the ground, and another root-system will be developed. We 

 see then In Fig, 12 that the hypocotyl is no longer straight, 

 and that it shows the beginning of a young root (r-'^) at the 

 base of the cotyledons, while the other roots still persist and 

 even increase slightly in length. The first leaf has assumed 

 its final shape and size, and another one (L-) has commenced 

 to unfold. If we follow 1;he further development of the seed- 

 ling we shall see, in Fig. 13, that there are now two distinct 

 ^ and different systems of roots, the first consisting of the pri- 



mary and earliest developed secondary roots (r^-r^), the 

 second consisting of two roots (r^-r^), the situation of which 

 IS below the cotyledons, or rather at the apex of the hypo- 

 cotyl. The cotyledons are still green and attached to the 

 stem, and four leaves have been developed. The primary 

 root-system is now beginning to fade away, and is replaced 

 by the second one, as maybe observed in Fig. 14. Here the 

 primary root has begun to die, the second ones next in the 

 course of development have already faded, while the new set 

 of roots is in rapid growth from the base of the young plant 

 (r^-r^), being more or less thick, and some of them having 

 - several lateral branches. Three leaves (L^-L'^) have finished 

 their growth and a fourth one (L-*) has appeared. As soon 

 as the plant has dropped the hypocotyl with the first system 

 of roots it shows its final manner of growth, /. ^., several 

 leaves crow^ded at the base of the flowering stem, and the 

 roots fibrous. 



This species should, according to A. Gray,* be biennial, 

 but it is certainly perennial. For, if we consider the 

 Fig. 15 on Plate VI, we shall sec the rhizome and the base o( 

 an older plant, which is at least three years old- The plant 

 does not flower during the first year, but forms only a number 

 of leaves, while the following year the inflorescence appears. 

 We see in Fig. 15 the persisting bases of the inflorescence 

 (F^) of a previous year (1889) and of some faded leav^es, the 

 plant then having attained an age of at least two years ; be- 



\ 



Asa Gray : Manual of Botany of the Northern United States, 6th Edition, 

 revised by Watson and Coulter, 1S90. 



