THE AMERICAN BOTANIST 103 



during their life cycle. Often these plants are entirely unrelated 

 as is the case with the apple rust whose initial stages occur on 

 the red cedar, or the corn rust which lives on species of oxalis 

 during part of its life. 



The Obedient Plant. — Physostegia Virginica is usually 

 called false dragon head or lion's heart in the books, but the 

 knowing ones call it obedient plant because of the curious 

 habit the flowers have of keeping any position in which they 

 may be placed. Turned either to the right or left, they do 

 not spring back when released as other flowers do. The struc- 

 ture of the pedicel which makes such changes possible appears 

 never to have been studied nor, so far as we know, has any 

 attempt been made to discover what use this peculiar faculty 

 is to the plant. Happening recently to pass numerous clumps 

 of this plant on a windy day, we observed that all the flowers 

 were turned away from the wind and remained in this position 

 during lulls in the breeze. We are disposed to suggest, there- 

 fore, until a better explanation is forthcoming, that the yielding 

 of the flower stalks to pressure of any kind serves to protect 

 the essential organs by turning the opening of the flower away 

 from danger. 



A Decorative Flax. — A most attractive and decorative 

 plant for the border is the perennial flax (Liuuiii perenne). 

 If planted in any good garden soil in a situation where it is 

 shaded for the early part of the day, it will reward its possessor 

 with a cloud of sky-blue flowers each an inch or more across, 

 from May until well into September. The flowers are rather 

 evanescent and usually fall from the plant by the middle of 

 the day, but new ones are produced daily and give the plant 

 an air of freshness throughout the summer. On single sprays 

 of this plant, we have counted the remains of no less than (35 

 blossoms showing a blooming season for single twigs of more 

 than two months. Blue flowers are never very abundant in 

 the flower garden. Many of those called blue have enough 



