734 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
1, Anthemis cotula L. Sp. Pl. 894. 1753. MAYWEED. 
Maruta cotula DC. Prodr. 6: 13. 1837. 
Type Loca.ity: ‘‘Habitat in Europae ruderatis praecipue in Ucrania.” 
RanaeE: Native of Europe, widely naturalized in North America, Asia, Africa, and 
Australia. 
New Mexico: Balsam Park, Sandia Mountains (Ellis 333). 
119. CHRYSANTHEMUM IL. Ox-rye palsy. 
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 leucanthemum pinnatifidum Lec. & Lam. Cat. Pl. France 
227. 1847. 
Chrysanthemum leucanthemum subpinnatifidum Fernald, Rhodora 5: 181. 1903. 
TYPE Locatity: ‘‘Mont Dore; paturages et pentes herbeuses de Chaudefour, bords 
du chemin de Sancy & Vassiviére,’’ France. 
New Mexico: Near Pecos (Cockerell), 
A native of Europe, widely introduced into North America. In the East it isa 
troublesome weed, but it is still very rare in most parts of the West. 
120. TANACETUM IL. 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. Pl. 844. 1753. 
TYPE LocaLity: ‘Habitat in Europae aggeribus.”’ 
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. Picrothamnus desertorum Nutt. Trans. Amer. Phil. Soc. n. ser. 7: 417. 1841. 
Artemisia spinescens D, C. Eaton in King, Geol. Expl. 40th Par. 5: 180, pl. 19. 1871, 
Tyre Locauiry: ‘‘Rocky Mountain plains in arid deserts, toward the north sources of 
the Platte.” 
Rance: 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. Sacresrusu. Wormwoop. 
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. 
