Genus 89. 



THISTLE FAMILY 



1. Achillea Ptarmica L. Sneezevvort. White 

 Tansy. Sneezewort- Yarrow. Fig. 4552. 



Achillea Ptarmica L. Sp. PI. 898. 1753. 



Perennial from horizontal or creeping rootstocks; 

 stem glabrous, or slightly pubescent, nearly or quite 

 simple, i-2 high. Leaves linear or linear-lanceolate, 

 sessile and slightly clasping at the base, acute at the 

 apex, regularly and closely serrate, sometimes pubes- 

 cent on the veins beneath, 1-2*' long. li"-3" wide; 

 heads not very numerous, s"-9" broad; peduncles pu- 

 berulent; involucre broadly campanulate, its bracts 

 ovate-oblong, obtuse or obtusish, slightly tomentose; 

 rays 5-15, white, rather large. 



In moist soil, Newfoundland, New Brunswick and Quebec 

 to Massachusetts and Michigan. Naturalized from Europe. 

 Native also of northern Asia. Go'ose-tongue. Wild, bastard- 

 or european pellitory. Fair-maid-of-France. Sneezewort- 

 tansy. July-Sept. 



YarrOW .. 



53- 



2. Achillea Millefolium L. 

 Milfoil. Fig. 4553. 



Achillea Millefolium L. Sp. PI. 899. 



Perennial from horizontal rootstocks ; flow- 

 ering stems pubescent, or nearly glabrous, sim- 

 ple, or corymbosely branched above, i-2 

 high. Basal leaves, and those of the numerous 

 short sterile shoots, mostly petioled, sometimes 

 10' long and V wide, those of the stem sessile, 

 all narrowly oblong or lanceolate in outline 

 and finely dissected into narrow pinnatifid seg- 

 ments, tomentose, pubescent or nearly glabrous ; 

 heads numerous, 2"-3" broad, in terminal com- 

 pound dense, somewhat convex or nearly flat- 

 topped corymbs; involucre ovoid-cylindric, its 

 bracts oblong, obtusish, pubescent ; rays 4-6, 

 white, or often pink or purple, less than 2" 

 broad. 



In various situations throughout eastern North 

 America, often occurring as a naturalized weed. 

 Native also of Europe and Asia. Old names, san- 

 guinary, thousand-leaf, nosebleed, old-man's-pep- 

 per, soldier's-woundwort, gordaldo. June-Nov. 



3. Achillea lanulosa Nutt. Woolly Yar- 

 row. Fig. 4554. 



Achillea lanulosa Nutt. Journ. Acad. Phila. 7: 

 1834. 



36. 



Similar to the preceding species, perennial by 

 rootstocks, l-2l high, densely _ silky-woolly 

 nearly all over. Leaves deeply bipinnatifid into 

 narrow lobes and segments, those of the stem 

 mostly sessile ; inflorescence convex, 2'-4' broad ; 

 involucre oblong-cylindric, its bracts greenish- 

 yellow, with brownish margins ; rays l"-2i" broad, 

 white. 



In dry soil, Quebec and Ontario to Michigan, 

 Yukon, south to Oklahoma, Mexico and California. 

 June-Sept. Locally naturalized eastward. 



Achillea ligustica All., differing from A. Millefo- 

 lium by being stouter with loosely corymbose heads, 

 native of Europe, has been found in cultivated ground 

 near Tannersville, New York. 



