A. CALIFORNICA. 55 



still seems the most reasonable. Whether or not the angular achenes signify a remote 

 connection with Crossostephium, it is very certain that nothing is gained by throwing 

 californica and australis into this genus on the basis of a single character and in the 

 face of decided differences in other important features. 



Much more direct is the connection between A. californica and two Old World species, 

 namely A. pontica and A. abrotanum. These are in agreement as to all essential features, 

 even down to the angled turbinate disk-achenes with broad shoulder-like summits, as is 

 shown in the accompanying plates. Angled achenes are encountered at a number of 

 places in the genus. Sometimes these angles are reduced to ribs which pass through 

 all degrees of depression until in some cases the surface seems to be perfectly smooth 

 (p. 37). Since the characters of strongly angled and crowned achenes are approximated 

 also in true Crossostephium, which because of its pappus and two rows of ray-flowers 

 may be accepted as still more primitive, A. pontica, A. abrotanum, and A. californica 

 (together with A. australis) may well represent the early stock from which the other 

 Artemisias have been derived. There is no reason to assume, however, that the other 

 species have arisen from these as they now exist, for although primitive in most of their 

 characters, each exhibits special development along certain lines and all are shrubby 

 in habit. This demonstration of the phylogenetic connections of californica and similari- 

 ties between it and the Hawaiian A. australis render more plausible the theory that it 

 has had some geographic connection, perhaps through Asia, with the primitive Old 

 World stock, as now represented by pontica and its allies. How californica came to be 

 stranded on the Pacific coast of North America is a problem that can not now be solved, 

 but it apparently resulted from the general circumpolar migration of the genus. 



Among the native American representatives of the section Abrotanum, Artemisia 

 californica stands alone. It is the only species, except for the anomalous A. bigelovi, 

 which is shrubby in habit. For these reasons it is assigned to a divergent line on the 

 phylogenetic chart. Whether it has arisen from a Crossostephium-like ancestor, or 

 whether of some other origin, its early segregation seems certain, in view of the absence 

 of direct connection with existing species. In aspect it is most like A. filifolia, which it 

 also represents ecologically on the Pacific Coast. WhUe it is not impossible that these 

 two are connected phylogenetically, the difference in nearly all technical characters 

 seems to render this improbable. 



The available evidence therefore points to the tentative conclusion that A. californica 

 is not directly related to any other American species, but that its connections are with 

 the Hawaiian A. australis and with certain Old World species, especially A. pontica 

 and A. abrotanum. Furthermore, these four species best represent the early stock 

 of Artemisia and hence the connection with the genus Crossostephium. 



ECOLOGY. 



In life-form Artemisia californica is a bush, which resembles both A. filifolia and 

 A. tridentata. It is the most important dominant of the Coastal sagebrush association, 

 extending from San Francisco Bay to the Mojave and Colorado Deserts, and blooming 

 through the summer. Typically, it is a climax dominant, but it is often subclimax to 

 the chaparral association in the habitat of the latter. It comes in contact with the true 

 sagebrush of the Great Basin at various places from Tehachapi Pass south to Lower 

 California, and the two not infrequently mingle on equal terms. Its lower contact 

 is with the Stipa bunch-grass prairie along the coast and in the interior savannah, and 

 with Larrea scrub at the desert's edge. Above it lies the Adenostoma-Ceanothus chapar- 

 ral, with Adenostoma and Artemisia in particular minghng over a narrow ecotone. 



The chief associates of the coast sagebrush are Salvia mellifera, S. apiana, S. nivea, 

 Eriogonum fasciculatum, Rhus integrifolia, Eriodictyum tomentosum, and Lotu^ glaber. 



