THE AMERICAN BOTANIST 97 



not the commonest. Desert conditions prevail when plants 

 cannot get sufficient water for their needs. Some regions 

 are deserts because the soil is actually lacking in moisture, 

 others are deserts because the water present holds in solution 

 salts or other substances that make it difficult for plants to 

 absorb it. Finally, there are the cold deserts which are dry, 

 not through lack of water, but because the water is locked 

 up in the form of ice and therefore not available to plants. 

 For nearly half of every year, the greater part of our country 

 is a cold desert of such dryness that only a very limited num- 

 ber of plants can remain green the year around. The plants 

 of such regions, however, have so long been accustomed to 

 a period of dormancy due to the lack of moisture that some- 

 thing of this nature now seems necessary to keep the life 

 processes running smoothly. It is well known that most plants 

 require some check to their vegetative vigor to make them 

 fruit well. Northern plants carried to southern regions some- 

 times fail to fruit at all because no check of the kind is 

 experienced. It is otherwise with such plants carried to re- 

 gions where a season of dryness prevails, for the dryness due 

 to heat and lack of water has the same effect as cold and the 

 consequent lack of water. This fact is of considerable com- 

 mercial importance. In regions where the cold desert type 

 occurs, a late frost may ruin the fruit crop of these plants 

 which blossom early, such as the peach, while in the dry 

 deserts, the danger from frost is slight and a crop is more 

 likely to be made. 



A Queer Bee Hive. — Early in May the writer, in com- 

 pany with Prof. Geo. H. Grinnell, of the Loss Angeles City 

 Schools, made a hurried trip to Santa Catalina Island in quest 

 of wild flowers for the annual exhibit of The Wild Flower 

 Club of The Southwest Museum. Those who read the list 

 collected on the trip last year will find most of the plants 

 gathered on this trip. A thing of special interest was the * 

 root of a Chilicothe vine {Micratnpelis macrocarpa) a vine 



