220 NORTH AMERICAN FLORA [VoLuME 34 
Bracts dull, yellowish. 15. A. occidentalis. 
Bracts shining, greenish on the back. 16. A. setacea. 
Ultimate leaf-segments ovate or lanceolate. 
Plant densely white-villous with long hairs; in- 
florescence very dense; ligules about 1.5 mm. 
long; leaf-segments crowded. 17. A. pannonica. 
Plant sparingly villous or glabrate; inflorescence 
open; ligules 2-3 mm. long. 
Leaves 2-4 mm. wide; segments densely crowded, 
ascending. 18. A. angustissima. 
Leaves 1-4 cm. wide; segments not crowded, 
spreading; rachis distinctly winged. 
Stem-leaves linear to lance- oblong in out- 
line, with numerous pairs of primary 
divisions; outer bracts obtuse. 
Leaves conspicuously punctate, their 
ultimate segments strongly callous- 
thickened towards the apex; ligules 
purplish. 19. A. asplenifolia. 
Leaves not conspicuously punctate, their 
ultimate segments not callous-thick- 
ened towards the apex; ligules white, 
rarely pink. 20. A. Millefolium. 
Stem-leaves oval or ovate in outline with 6-8 
pairs of primary divisions; outer bracts 
acute. 21. A. ligustica. 
Rachis of the leaves dentate throughout, broadly winged; leaves 
lanceolate in outline, with broad obovate ultimate divisions. 22. A. dentifera. 
Leaves serrate or incised, not pinnatifid. 
Ligules about 1 mm. long; leaves incised. 
Ligules about 5 mm. long; leaves serrate. 
. multiflora. 
. Ptarmica. 
OD 
1. Achillea tomentosa L. Sp. Pl. 897. 1753. 
Alitubus tomentosus Dulac, Fl. Hautes-Pyr. 500. 1867. 
Millefolium tomentosum Fourr. Ann. Soc. Linn, Lyon II.17: 91. 1869. 
A low perennial, with a rootstock; stem 1—2.5 dm. high, erect or ascending, sulcate, simple, 
villous; leaves 2-5 em. long, 3-5 mm. wide, linear in outline, densely villous, bipinnatifid, with 
short crowded divisions, the ultimate ones narrowly lanceolate, spinulose-mucronate; heads 
rather few, in a dense corymbiform panicle; involucre 3-4 mm. high, 2-3 mm. broad, villous; 
bracts about 15, in 3—4 series, oval to elliptic, rounded at the apex, yellowish with borders of the 
same color; ray-flowers 3-5; ligules bright-yellow, flabelliform or suborbicular, with 3-5 rounded 
lobes, 1.5—-2 mm. long; disk-flowers 20-25; corollas yellow, 3 mm. long; achenes nearly 2 mm. 
long, scarcely margined. 
TYPE LOCALITY: France. 
DISTRIBUTION: Westford, Massachusetts; adventive from the mountains of southern Europe. 
ILLustRaTIons: Engl. Bot. pl. 2532; Bot. Mag. pl. 498; Reichenb. Ic. Fl. Germ. 16: pl. 1022, 
II-III; Coste, Fl. Fr. f. 1967; Fl. Deuts. ed. 5. pl. 3026. 
2. Achillea borealis Bong. Mém. Acad. St.-Pétersb. VI. 2: 149. 
1832. 
Ptarmica borealis DC. Prodr. 6: 21. 1837. 
Achille Mis tletolpne accidentals Ledeb. Fl. Ross. 2: 532. 1846. Not A. Millefolium occidentalis DC. 
Achillea anethifolia Fisch.; Herder, Bull. Soc. Nat. Mosc. 38: 404, as synonym. 1865. 
A perennial, with a rootstock; stem 3-8 dm. high, striate or grooved, sparingly long-villous; 
leaves bi- or tri-pinnatifid, sparingly villous, the lower petioled, often 2-3 dm. long, 2-6 em. 
wide; upper leaves sessile, lanceolate with a broad base, 1-2 cm. wide; primary divisions ovate 
in outline, spreading; ultimate divisions linear, spinulose-mucronate; heads numerous, in more 
or less compound corymbiform panicles; involucre fully 5 mm. high and 4 mm. broad; bracts 
20-25, ovate or ovate-lanceolate, all acute, the outer ones half as long as the innermost; margins 
dark-brown or nearly black; ray-flowers 5 or 6; ligules white or pink, 3-4 mm. long, nearly 
orbicular, round-lobed; disk-flowers 20-25; corollas yellowish-white, 3 mm. long, glandular- 
granuliferous; achenes nearly 3 mm. long, strongly wing-margined. 
Type Locatity: Island of Sitka, Alaska. 
DISTRIBUTION: Vancouver Island to Alaska and Yellowstone Park; California (?); also ia 
eastern Siberia. 
