COMPOSITAE (COMPOSITE FAMILY) 845 



1. G. lutea Greene. Erect or nearly so, 4 dm. or more in height, puherulent 

 and someichat scabrous^ leafy-stemmed, branched above ; branches ascending ; 

 leaves oblong-lanceolate, somewhat amplexicaul at the broadish base, toothed or 

 siibentire ; both ilisk-flowers and rays yeUoic. (G. lanceolata of auth.. in part, 

 not Michx.) — Mo. {Bush) to Tex. 



2. G. aristata Pursh. YevewmdX^ hirsute ; leaves lanceolate to oblanceolate, 

 broad or narrow, entire to coarsely pinnatifid ; disk-Jlowers brownish-purph ; 

 rays usually numerous and long, yellow; chaff bristly or subulate. — Minn, to 

 Man., westw. and southw. ; now spreading eastw. 



66. DYSSODIA Cav. Fetid Marigold 



Heads many-flowered, usually radiate ; rays pistillate. Involucre of 1 row of 

 bracts united into a firm cup, with a few loose bracts at the base. Keceptacle 

 flat, beset with short chaffy bristles. Achenes slender, 4-angled ; pappus a row 

 of chaffy scales, dissected into numerous rough bristles. — Herbs, mostly annuals 

 or biennials, dotted with large pellucid glands, which give a strong odor ; heads 

 terminating the branches ; flowers yellow. (Name dvsojdia, an ill smell, which 

 the plants exemplify.) Boebera Willd. 



1. D. pappbsa (Vent.) Hitchc. Nearl}' smooth, diffusely branched, 1-5 dm. 

 high ; leaves opposite, pinnateiy parted, the narrow lobes bristly-toothed or cut ; 

 rays few, scarcely exceeding the involucre. (D. chrysanthemoides Lag.) — Road- 

 sides and banks of rivers, Minn, to 111., Tenn., and south westw. ; occasional as 

 a weed further eastw. July-Get. 



67. ACHILLEA [Vaill.] L. Yarrow 



Heads many-flowered, radiate ; the rays few, fertile. Involucral bracts 

 imbricated, with scarious margins. Receptacle chaffy, flattish. Achenes 

 oblong, flattened, margined ; pappus none. — Perennial herbs, with small 

 corymbose heads. (So named because its virtues are said to have been discov- 

 ered by Achilles.) 



* Leaves simple ; involucre hemispherical ; receptacle low. 



1. A. Ptarmica L. (Sneezeweed.) Stem rather rigid, smooth or slightly 

 pubescent; leaves lance-linear, tinely appressed-serrate ; corymb loose, the heads 

 long-pediceled ; rays 8-12, white, much longer than the involucre. — Damp 

 fields, etc., Nfd. to Mich, and Mass., local. Aug., Sept. (Introd. from Eu.) 



* * Leaves bipinnately parted ; involucre slender-cylindric ; receptacle becoming 



elongated. 



-t- Bays comparatively showy, their blades ^-| as long as the invohicre ; bracts 



with dark brown or black margins. 



2. A. boiealis Bongard. Stem erect, 0.5-4 dm. high, more or less lanate ; 

 stem-leaves fev: (5-9), silky-lanate especially beneath ; corymbs 2-(J cm. broad, 

 very convex; involucre 4-6 mm. long, its bracts all dark-margined ; rays 10-20, 

 white (rarely pink), short-oblong or suborbicular, 2.5-4 mm. long. — Wet rocks 

 and mossy slopes. Lab. to Alaska, s. to Nfd., e. Que., and along the Rocky Mts. 

 to N. Mex. June-Aug. (Boreal Eurasia.) 



•*- -t- Bays small, their blades rarely I as long as the involucre; bracts pale, 



very rarely the uppermost dark-margined. 



3. A. Millefolium L. (Common Y., Milfoil.) Stem simple or sometimes 

 forked above, o-lO dm. high, arachnoid or nearly smooth ; stem-leaves numerou.''t 

 (8-15), smooth or loosely pubescent ; coi-yynbs very ccnnpound, 0-20 cm. broad, 

 flat-topped, the branches stiff ; involucre 3-5 mm. long, its bracts all pale, or in 

 exposed situations the uppermost becoming dark-margined ; rays 5-10, white 

 to crimson, short-oblong, 1.5-2.5 mm. long. — Fields and river-banks, common. 

 (Eurasia.) 



4. A. lanulbsa Nutt. Similar; stem 3-6 dm. high, densely woolly; stem- 



