124 



GENUS ARTEMISIA. 



panicle, 2 to 10 cm. broad; heads sessile, erect, hemispheric; involucre 3.5 to 4.5 mm. high, 

 3.5 to 4.5 mm. broad, densely villous, disk-flowers 12 to 25, the corolla 2 to 3 mm. long. 

 (OUgosporus pycnocephalus Lessing, Linnaea 6:524, 1831.) Sandy beaches along the 

 Pacific Ocean from Oregon south to Point Sur, California. Type locality, California. 

 Collections : Coos County, Oregon, House 4991 (NY) ; Samoa, Humboldt County, Cali- 

 fornia, Tracy 3023 (DS, UC, US) ; Bodega Point, California, Eastwood 4801 (SF) ; West 

 Berkeley, San Francisco Bay, California, Davy 868 (UC) ; Point Sur, Monterey County, 

 California, July, 1888, Brandegee (UC). 



MINOR VARIATIONS AND SYNONYMS. 



Several of the variations indicated below have been assigned specific rank by other writers. This is not sur- 

 prising in view of the striking superficial differences between some of them. This unlikeness is sometimes due 

 to varying amounts of pubescence. Thus, within a single subspecies there may be found some plants that are 

 quite green and glabrous as well as others that are hoary pubescent. Again, the degree of branching gives rise 

 both to spicate and loosely paniculate inflorescences, but with all intermediate stages represented. Such char- 

 acters are so obviously ecologic, as indicated especially by field observations, that the resulting forms are not 

 given even subspecific rank. A large number of varieties are recognized by Europ>ean botanists (see especially 

 Rouy in Rev. Bot. Syst. Geog. Bot. 1 :295, 1903, and Fl. France 8:293, 1903). 



1. Artemisia bobealis Pallas, Raise 3:755, 1776.-4. campeslris borealis. 



la. A. BOREALIS BESSERi TorTcy and Gray, Fl. N. Am. 2:417, 1843. — Based upon A. borealis purshi 

 Besser, which see. 



2. A. BOREALIS PURSHI Besser, in Hooker, Fl. Bor. Am. 1:326, 1833. — Based upon A. spithamaea Pursh, 

 which see. 



3. A. BOREALIS SPITHAMAEA Torrey and Gray, 1. c. — A. campeslris spithamaea. 



4. A. BOREALIS woRMSKioLDi Besser, in Hooker, Fl. Bor. Am. 1:327, 1833. — The same as A. campeslris 

 borealis, from the description. The original specimens came from "Columbia River and Islands, Northwest 

 America" and Kotzebue Sound. 



5. A. BOURGEAUANA Rydberg, Bull. Torr. Club 37:454, 1910. — A form of A. campeslris spithamaea charac- 

 terized by a slightly taller habit and a dense, leafy panicle. The types, which came from Saskatchewan, are 

 3 to 4 dm. high and therefore nearly matched in height by specimens from Cameron Pass, Colorado (July 24, 

 1894, Cranddl, NY), which are 3 dm. high but 

 with all other features of spithamaea. The 

 panicles in the types are 25 cm. long and 3 cm. 

 broad. Although closely approached in some 

 specimens of spithamaea, the large size of the 

 inflorescence constitutes the best character of 

 the form. 



6. A. CAMPESTRis GENinNA Herder, PL 

 Radd. 3:57, 1864.— Probably the same as 

 A. campeslris lypica. 



7. A. CAMPORUM Rydberg, N. Am. Fl. 34: 

 254, 1916. — The lower and less leafy form of 

 A. campeslris pacifica, although authentically 

 named specimens are often up to 7 dm. high 

 and as leafy as in this. The inner bracts are 



said to be rounded as compared with the acutish inner bracts of pacifica. In order to test the constancy of 

 this character, 6 sheets were selected from the herbarium of the New York Botanical Garden, 3 of which had 

 been determined for the North American Flora as pacifica, the other 3 as camporum. Heads from these speci- 

 mens were given to the artist with directions to draw to scale an average inner bract from each, preserving the 

 original shape as far as possible. The resulting drawings are shown in figure 17, and seem to indicate that the 

 shape of the inner bracts does not here afford a safe criterion for the separation of forms. The type locality 

 of camporum is Saskatchewan. 



8. A. CANADENSIS Michaux, Fl. Bor. Am. 2: 128, 1803. — A variation of A. campeslris borealis. The original 

 characterization is too brief to permit a determination of the exact form. But since the type locality is Hudson 

 Bay, where typical borealis grows, there is no reason to assume that it is fundamentally different from that 

 subspecies. In the Synoptical Flora, Gray greatly extended Michaux's species to include the common small- 

 headed form of the western United States now referred to subspecies pacifica and separated this from his A. 

 borealis Pallas, chiefly on the numerous heads in a compound, oblong or pyramidal, virgate panicle. But Gray 

 himself admitted that the panicle was reduced in northern forms. It proves impossible to use the form of 

 the inflorescence to distinguish varieties in this region. The original figure of Pallas (Reise, 3 : 129, 1776) 



Fio. 17. — Inner bracts of ArlemUia campeatria pacifica; a, b, c, from 

 specimens of genuine pacifica; d, e, f, from specimens 

 authentically determined as A. camporum Rydberg 

 (minor variation 7). Collections represented: a, Leiberg 

 1580; b, Macoun S6SU; c, Butler 6iS; d, Clements 158; 

 e, Oterholta; /, Rydberg 203; all in the Herbarium of 

 the New York Botanical Garden. All X 8. 



