126 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



IV.— FURTHER OBSERVATIONS ON THE MANZANITAS OF 

 MT. TAMALPAIS. 



Since the publication of the article on the " Manzanitas of 

 Mt. Tamalpais,"^ I have been able to explore parts of 

 the mountain and the neighboring hills hitherto unknown 

 to me. Scarcely a week has passed that I have not spent 

 Sundav on the hills of Marin County. As a result of 

 these frequent visits and the new territory explored, 

 new facts concerning the distribution, time of blooming, 

 and characteristics of the different species of Arcto- 

 staphylos have been observed. 



1. Arctostaphylos nummularia Gray. — This I have 

 found only on Mt. Tamalpais proper. It does not seem to 

 grow on the hills around Fairfax, where the Big Carson 

 and the Little Carson Creeks take their rise, nor on the 

 ridge between Bear Valley and Bolinas. It is abundant on 

 the Boot-jack and Throckmorton Trails, also on the trail 

 leading directly from Mill Valley up the mountain and on 

 the trail from the Potrero to the head of Cataract Gulch. 

 While well formed fruit can be found at almost any time of 

 the year, ripe fruit is seldom seen and never persists as 

 does the fruit of all the other species. 



2. Arctostaphylos canescens Eastwood. — This, too, 

 seems to be confined to Mt. Tamalpais and apparently 

 grows only on the southern slope. It loves bleak, gravelly 

 hillsides, where it often holds exclusive possession. On the 

 Throckmorton Trail a few bushes are to be seen, a few more 

 on the Bill Williams Trail; but on the West Point Trail it 

 is abundant, adorning the slopes during the winter with its 

 blooming bushes. 



On November 7th, the first flowers were seen. The 

 plants on the Throckmorton Trail were beginning to bloom. 

 The delicate pink blossoms have their beauty much 

 enhanced by the gray-green foliage. From this date until 



See this Vol., p. 81. 



