82 MADRONO [Vol. 1, 



8. A. manzanita Parry is the largest species of the genus, 

 though the trunk of A. glauca may sometimes become as massive. 

 In the Napa Range A. manzanita forms interesting pigmy forests 

 8 to 14 feet high on the lower western slopes of Howell Mt. Some- 

 times it is massed in closed stands, appearing as smooth as a meadow 

 floor when seen from above. In more open situations the individuals 

 become 13 to 22 feet high. In Lyons Valley on the westerly slope 

 of Howell Mt. measurements of three especially large individuals 

 were secured: a. Near Stingy Stile, Eden trail to Adam and Eve, 

 height 15 ft.; trunk 4 ft. high before branching into 4 arms; trunk 

 diameter at 3 ft. above ground, 1 ft. 2 in. b. Shoulder of hill to right 

 of trail, 35 yards easterly from Stingy Stile, height 18 ft.; trunk 2 

 ft. high before branching into 5 arms; trunk diameter at 13^ ft. 

 above ground, 1 ft. 2 in. c. On the little ridge to west of Lyons 

 Valley, tree by path, height 22 ft.; trunk 1 ft. 8 in. before branch- 

 ing into 2 arms; smallest trunk diameter (at ground) \\% in. 



Arctostaphylos manzanita is killed outright under chaparral 

 fires. One sees the dead bodies of these arborescent shrubs, 8 to 

 15 feet high, standing like white skeletons in the fire-burns of 

 chaparral areas, for they soon lose their red-brown bark and reveal 

 the white sapwood beneath. While shallow-rooted, they are not as 

 shallow-rooted as A. stanfordiana, the bodies of which are over- 

 thrown in the first winter storms. A. manzanita on the other hand 

 may stand for some years, but finally the roots decay and a touch 

 will send an individual crashing to the ground. 



Arctostaphylos manzanita, therefore, reproduces exclusively by 

 seed. It is an aggressive species. At the present time, in the centers 

 of its greatest development, it is invading new areas or recovering 

 old ones. Along the Napa Range and in Mendocino Co. considerable 

 slopes on the lower hills were cleared thirty to forty years ago for 

 cultivation or grazing. Within ten or fifteen years much of this 

 land has been permitted to revert to primitive conditions. Seedlings 

 of this species appear in large numbers in these neglected fields 

 or old vineyards, as they do also on burns. Such seedlings represent 

 a cumulative crop of seeds — perhaps ten to forty years — and in- 

 dicate the long persistent vitality of the seeds. 



Along the lower slopes bordering the valleys of central Men- 

 docino Co., about Ukiah Valley, and particularly from Long Valley 

 to Cummings, Arctostaphylos manzanita is abundant. It occurs 

 mostly below the open stand of Quercus kelloggii and Pinus 

 ponderosa, covering the bases of low hills which border the narrow 

 valleys and colonizing the opens and flats. From Cummings one 

 may follow it westward to the headwaters of the South Fork Eel 

 River in western Mendocino Co. where it occurs near Piercey sta. 

 In the inner Coast Range it is less frequent or rare, but is found on 

 Mt. Diablo; summit of the Vaca Mts.; and near Jerusalem Valley, 

 Wilbur Sprs., and Indian Valley — all in eastern Lake Co. In the 

 Sierra Nevada foothills it occurs from Tehama Co. south to Tuo- 



