TREES AND SHEUBS 39 



cuttings taken from the staminate* or so called "male" trees. 

 The second difficulty necessitates the cutting out of the mistle- 

 toe about once a year; if properly watched the parasite never 

 becomes very objectionable. 



The best feature of the cottonwoods is their very rapid 

 growth. Five years of proper treatment will generally insure 

 a good sized shade tree, and when once established they require 

 very little attention. As an "all around" shade tree for the 

 streets, roads, and drives there is probably nothing better 

 growing in the State. Their symmetrical rounded tops, their 

 glossy leaves ever whispering to the slightest breeze, their 

 glorious golden heads, when the first frosts come, their almost 

 perfect adaptation to the conditions of the valleys in which we 

 live, make them most excellent trees to have about our homes. 



The Valley Cottonwood (Populus wislizeni). This is 

 the common tree of the lower irrigable valleys of all the south- 

 western arid region from the Rio Grande to the Pacific, and 

 forms much the greater part of the "bosques" of the Rio 

 Grande, the Gila and the lower Pecos valleys. Wherever the 

 land is under cultivation, this cottonwood is used more or 

 less as a shade tree, or in a few cases, for windbreaks. It is 

 a particularly rapid grower, and in the valley where the water 

 table is but a few feet below the surface, these trees soon get 

 their roots down to the water and do not need to be irrigated. 

 As has already been suggested, it is necessary to protect them, 



• Possibly it would be wise to explain just 'what is meant by the stam- 

 inate trees, for the benefit of those who have not studied botany. The 

 cottonwoods belong to that group of plants in which the two organs 

 necessary to the production of seed (i. e. stamens and pistils) are borne 

 upon separate trees. The stamens furnish the pollen, (or yellow fertilizing 

 dust) and after the very simple flowers which contain the stamens cease 

 blooming, the trees bearing them show no further evidence of being con- 

 cerned in seed production. The troublesome cotton consists of numerous 

 hairs which surround the seeds to assist in their distribution, hence Is 

 only produced by the seed bearing or "female" trees. The ' staminate 

 flowers are reddish or brownish or sometimes a dull yellow, and hang 

 In pendulous spikes which appear on the trees before the leaves. They 

 show no sign of the green berry like balls which contain the seed. The 

 pistillate catkins, however, are green, and each flower consists of little 

 else than a rudimentary ball with the expanded stigma above it. There 

 are fewer flowers on these catkins and they usually appear with the first 

 leaves or a little later. 



