Notes on the Monterey Pine

George J. Peirce
1904 Botanical Gazette  
IN the spring of I 898 the entomologists of Stanford University discovered a fly, IDzilosis pini-radiatat Snow,' which produced a leaf-gall or at least a basal hypertrophy of the leaves (needles) of the Monterey pine (Pinus radiata D. Don.) Some of the botanical features of this insect attack were described in i900 by Cannon.2 Certain other features, as well as notes on other matters connected with this tree, I wish to add to what Cannon said. As its name implies, the Monterey pine is a coast
more » ... y pine is a coast tree, veryy restricted in its distribution: Pescadero, southwest df Monterey and Pacific Grove."3 It is commonly planted, however, over a rather extended territory, though with a success which is evidently proportioned to two things: the rainfall and the humidity of the air in summer. It seems to thrive about San Francisco and on the ocean side of the peninsula which separates the southern half of San Francisco Bay from the sea, but it needs moister, cooler air in summer than it gets in this part of the Santa Clara Valley, although careful watering will keep it in fair condition even here. Along with the coast redwood (Sequoia sempervirens Endl.) this tree is subject to a great variety of enemies, in addition to being exposed in cultivation to unfavorable climatic conditions. In the arboretum of the university the unfavorable factors in the environment are most evident. To mention only conspicuous enemies of the pine, one finds Arceut/zobium occidentale,4 a Peridermium, certain fungi causing spots on the leaves,scale-insects, bark-borers,and the gall-
doi:10.1086/328509 fatcat:boqyuacmxbh7vovnrgaigufu7i