80 GENUS AETEMISIA. 



lln. Artemisia vulgaris mexicana (Willdenow). — Stems erect, 3 to 8 dm. high, 

 from slender herbaceous rootstocks, more densely leafy than in most other varieties; 

 lower leaves narrowly oblanceolate, cleft into several very slender lobes; principal leaves 

 linear or the outline often oblanceolate because of the divergent lobes, 3 to 10 cm. long, 

 only 0.2 to 0.4 cm. wide when entire but up to 5 cm. wide across the spreading lobes 

 when these are present, typically cleft nearly to the midrib into elongated linear acute 

 lobes 2 to 4 mm. wide, those of the inflorescence chiefly entire, all leaves green and lightly 

 tomentose or glabrate above, densely white-tomentose beneath, the margins narrowly 

 revolute; inflorescence a leafy panicle, 3 to 8 cm. broad; involucre campanulate, 2.5 to 3 

 mm. high, about 3 mm. broad, or 4 mm. high and broad in form known as A. ghiesbreghti 

 Rydberg, gray-tomentose, perhaps sometimes only sparingly so, 15- to 30-flowered. 

 {A. mexicana Willdenow; Sprengel, Syst. 3:490, 1826.) Dry plains from Missouri, 

 southern Colorado, and Texas to New Mexico and probably Arizona, thence south 

 and apparently common to San Luis Potosi, Durango, Jalisco, Vera Cruz, Yucatan 

 (according to Millspaugh, Field Mus. Nat. Hist. Bot. 1 :323, 1896), Chiapas, and probably 

 into Guatemala. Type locality, Mexico. Collections: Greenwood, Missouri, Bush ^12 

 (Gr, NY, US, minor variation 36, A. lindheimeriana Scheele); Wichita, Kansas, Poole 

 1300 (US, same variation) ; foot of Spanish Peaks, Colorado, September 3, 1873, Greene 

 (Gr) ; Naturita, southwestern Colorado, Payson 590 (Gr) ; White Mountains, New Mexico, 

 Wooton SU (Gr, UC, US); Black Range, New Mexico, Metcalfe 1248 (NY, type of 

 A. neomexicana Greene, minor variation 57); Weatherford, Texas, Tracy 8135 (Gr); 

 near Chihuahua City, Chihuahua, Pringle 290 (NY, type of A. revoluta Rydberg); 

 near San Julian, Chihuahua, Nelson 4939 (Gr, US) ; Sierra des Parras, Coahuila, Purpus 

 4-659 (UC, condensed form with short leaves and narrow inflorescence; perhaps nearer 

 subspecies ludoviciana) ; near Durango, Palmer 907 (Gr, UC, US); Alvarez, San Luis 

 Potosi, Palmer 59 (Gr, UC, US) ; Tula, Hidalgo, Pringle 9848 (Gr, NY, US) ; slopes of 

 barranca of Guadalajara, 1,380 m., Jalisco, Pringle 8765 (Gr, UC, US); Eslava, Federal 

 District, Mexico, Pringle 11820 (Gr, US, heads exceptionally large, minor variation 21, 

 A. ghiesbreghti Rydberg); Esperanza, Puebla, Arsene 2113 (US); Orizaba, Mueller 1868 

 (NY, type of A. muelleri Rydberg, minor variation 55). 



llo. Artemisia vulgaris wrighti (Gray). — Stems erect, 3 to 6 dm. high, from short 

 creeping rootstocks; lower leaves of sterile shoots elliptic or lanceolate, entire, densely 

 white-tomentose on both sides; lower leaves of flowering stems usually cleft or divided 

 into linear-filiform lobes; principal leaves oblanceolate in outline, 1 to 5 cm. long, 0.5 to 

 1 cm. wide including spread of the lobes, some of upper ones entire but mostly cleft or 

 divided into linear-filiform acute lobes, these 0.5 to 1 mm. wide, those of the inflorescence 

 reduced but similar, all leaves white-tomentose on both sides (minor variation 8, A. 

 carruthi Wood), or greener and glabrate above (tjT)ical), those of the inflorescence reduced 

 but similar, the margins closely revolute; inflorescence a close panicle, 1 to 3 cm. broad, 

 or the individual panicles so arranged as to form a more compound and much broader 

 inflorescence, or sometimes reduced to a nearly simple raceme; involucre campanulate, 

 3 to 3.3 mm. high, 2 to 2.5 mm. broad (larger in forms known as A. pringlei and A. 

 prescottiana), pale, tomentulose, 10- to 35-flowered. (A. wrighti Gray, Proc. Am. Acad. 

 19:48, 1883.) Kansas to western Texas, Chihuahua, Arizona, Utah, and central Colo- 

 rado; an aberrant type reported from the Columbia River (minor variation 63, A. pres- 

 cottiana Besser); introduced into Missouri and Rhode Island. Type locality, Santa 

 Rita del Cobre, New Nexico, according to Rydberg. Collections (many are the form 

 known as A. carruthi Wood, i. e., minor variation 8) ; Pawtucket, Rhode Island, on wastes, 

 October, 1898, McCudden (Gr); Lane County, Kansas, Hitchcock 302 (Gr, NY, US, 

 apparently the type collection of A. kansana Britton, minor variation 33); Amarillo, 



