EARLY SUMMER FLOWERS 221 



ground. At any of these points or from the terminal bud a 

 new plant may be established. It becomes free from the 

 parent by the ultimate decay of the intervening region of the 

 runner, and is at such a distance from the parent as to lessen 

 the danger of competition. If we examine the base of a flower- 

 ing plant we can often distinguish the end of the runner passing 

 into the somewhat swollen stem described above. 



THE YELLOW IRIS OR FLAG (Iris Pseudacorus, L.). 



Two kinds of Iris, of which much the commoner is the Yellow 

 Flag (Coloured Plate), grow wild in Britain. The following de- 

 scription of this will, however, assist the student in examining 

 other kinds of Iris, whether wild or cultivated, allowance being 

 made for differences in detail. The Yellow Flag grows best in 

 damp spots, in marshy ground and by the sides of small streams 

 and ditches. It often occupies a considerable area, and its long 

 erect bluish-green leaves and large yellow flowers make it a con- 

 spicuous plant during the summer. If the spot where it grew is 

 examined in winter no trace of the foliage will be seen, only the 

 underground parts remaining, as is the case with so many of our 

 perennial plants. 



Plants should be carefully dug up and the underground stem 

 and roots washed free from the soil. Many of the stems will be 

 found to end in vegetative shoots. Others, however, have pro- 

 jecting from among the foliage-leaves a tali inflorescence, which 

 bears a succession of large flowers. The two kinds of shoot 

 require separate study. 



In a plant without an inflorescence we recognise the thick 

 horizontal stem more or less completely covered by the soil. Its 

 surface is brown, but when cut across the tissue within is pinkish. 

 The older parts bear the remains of foliage-leaves of former years ; 

 these are transverse scars almost encircling the stem. Projecting 

 from them are long, brown, bristle-like threads, the remains of the 

 more persistent tissues of the leaf -base. Two kinds of roots spring 

 from the stem. From the lower surface a number of stout cylin- 

 drical whitish roots grow vertically down into the soil. They are 

 at first unbranched, but later become attached to the soil by a 



