734 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



1. Anthemis cotula L. Sp. PI. 894. 1753. Mayweed. 



Ilaruta cotula DC. Prodr. 6: 13. 1837. 



Type locality: "Habitat in Europae ruderatis praecipue in Ucrania." 



Range: Native of Europe, widely naturalized in North America, Asia, Africa, and 

 Australia. 



New Mexico: Balsam Park, Sandia Mountains (Ellis 333). 



119. CHRYSANTHEMUM L. Ox-eye daisy. 



Perennial herb with alternate, dentate or incised leaves and pedunculate heads of 

 yellow flowers with white rays; involucre hemispheric, the oblong-lanceolate bracts 

 appressed-imbricated in several series; achenes angled or terete, 5 to 10-ribbed; 

 pappus none. 



1. Chrysanthemum leucanthem.um. pinnatifidum. Lee. & Lam. Cat. PI. France 



227. 1847. 



Chrysanthemum, leucanthemum sxih pinnatifidum Femald, Rhodora 5: 181. 1903. 



Type locality: "Mont Dore; paturages et pentes herbeuses de Chaudefour, bords 

 du chemin de Sancy a Vassivieie," France. 



New Mexico: Near Pecos (CocJcerell). 



A native of Europe, widely introduced into North America. In the East it ia a 

 troublesome weed, but it is still very rare in most parts of the West. 



120. TANACETUM L. Tansy. 



Erect, strongly scented, perennial herb with alternate, pinnately divided leaves and 

 numerous discoid corymbose heads; involucres hemispheric, the oblong-lanceolate 

 bracts appressed in several series; achenes 5-angled, truncate; pappus a short crown. 



1. Tanacetum vulgare L. Sp. PI. 844. 1753. 



Type locality: "Habitat in Europae ag^eribus." 



New Mexico: Farmington; Cedar Hill; Aztec. 



The plant is well established at these places. It is common in cultivation and 

 has become naturalized in many parts of the United States. 



121. PICROTHAMNUS Nutt. 



Low shrub, 50 cm. high or less, with numerous spreading spiny branches; leaves 

 small, pedately 5-parted, the divisions 3-lobed; heads globose, racemosely glomerate, 

 on short branches; involucral bracts 5 or 6, broadly obovate; female flowers 1 to 4, 

 sterile ones 4 to 8; achenes and flowers densely covered with long cobwebby hairs. 



1. Picrothamjius desertorum Nutt. Trans. Amer. Phil. Soc. n. ser. 7: 417.1841. 



Artemisia spinescens D. C. Eaton in King, Geol. Expl. 40th Par. 5: 180. pi. 19. 1871. 



Type locality : ' ' Rocky Mountain plains in arid deserts, toward the north sources of 

 the Platte." 



Range: Idaho and Montana to California and northwestern New Mexico. 



New Mexico: Carrizo Mountains; Farmington; Aztec. Dry hills, in the Upper 

 Sonoran Zone. 



122 ARTEMISIA L. Sagebrush. Wormwood. 



Bitter aromatic herbs or shrubs with alternate, entire to pinnatifid leaves and 

 small rayless heads of inconspicuous, yellow, whitish, or brownish flowers in panicles 

 or rarely in simple racemes; heads few to many-flowered, the flowers homogamous or 

 heterogamous; bracts imbricated in few series; anthers commonly tipped with subu- 

 late-acuminate, erect appendages; achenes mostly with a small epigynous disk and no 

 pappus. 



