THE AMERICAN BOTANIST. Ill 



covering already present in the region, may be such that the 

 intruder becomes an integral part of the flora and it may 

 indeed perish in its original habitat and in the places success- 

 ively occupied by it, leaving us no clew as to its place of origin. 

 —D. T. MacDougal, in Plant World. 



Law and the Barberry. — Plant students of the present 

 day are familiar with the fact that the wheat rust, which does 

 great damage to various grains, ordinarily begins its existence 

 by producing cup-like fruiting parts, called aecedia, upon the 

 leaves of the barberry. By means of spores borne in the ae- 

 cidia it is able to spread rapidly to the grain later in the sea- 

 son. Long before the real nature of the wheat rust was dis- 

 covered, observant farmers had noted the connection between 

 the barbarry and rusted grain and as early as 1755 the then 

 Province of Massachusetts passed "An Act to Prevent Dam- 

 age to English Grain Arising from Barberry Bushes" which 

 fixed a penalty of a two-shilling fine for every bush left stand- 

 ing after a certain date. 



Desert Flowers. — A desert is popularly regarded as a 

 vast stretch of sandy sterile soil upon which no rain falls and 

 in which, therefore, plants cannot grow. A more accurate 

 definition of a desert would be, a region in which rain falls 

 at such long intervals during part of the year that most 

 plants cannot maintain a continuous vegetative existence. Cer- 

 tain plants like the cactus and agave or century plant, store 

 up water during rains for use in drouths and are thus con- 

 sidered true Xerophytes, but many thin-leaved annuals have 

 learned the habits of the dessert and thrive even in such inhos- 

 pitable regions. At certain seasons of the year, especially im- 

 mediately after the rainy season, plants spring up as if by 

 magic and carpet the waste with flowers. In many places there 

 are so many plants that they crowd one another. A count of 



