Yarrow

Achillea pannonica Scheele, Linnaea 18: 471. 1844
Achillea lanala Spreng.; Willd. Enum. 915. 1809. Not A. laiiata Lam. 1778. Achillea Millefolium lanala Koch, Syn. Fl. Germ. ed. 2. 411. 1844.
A perennial, with a creeping cylindric rootstock; stem erect, simple, 3-6 dm. high, densely silkyvillous, grooved; leaves bipinnatifid, densely silkyviUous, 41 cm. long, the lower petioled, linear-oblanceolate in outline, 1-2 cm. wide, the upper linear, sessile, 0.5-1 cm. wide; primary divisions short, usually close together and ascending; rachis narrowly winged; secondary segments densely crowded, usually cleft into a few ovate, callous-mucronate lobes; heads in dense rounded corymbiform panides; involucre campanulate, 4 mm. high, 2-2.5 mm. broad; bracts 15-18, %t11ous, in 4 series, the outer ovate, acute, half as long as the innermost; inner bracts elliptic, obtuse; ray-flowers usually 5; ligules white, almost orbicular, 1.5 mm. long, roundly 3-lobed; disk-flowers about 12; corollas yellowish-white, 2.5 mm. long, sparingly glandular-granuliferous; tube about equaling the trumpet-shaped throat.
TvTE LOCALITY: Near Pest, Hungary.
Distribution: Nantucket Island, Massachusetts, and Gasp6 Peninsula, Quebec; adventive from Europe.