COMPOSITAE (COMPOSITE FAMILY) 845 



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

 and somewhat scabrous, leafy-stemmed, branched above ; branches ascending ; 

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

 subentire ; both disk-flowers and rays yellow. (G. lanceolata of auth., in part, 

 not Michx.) Mo. (Bush} to Tex. 



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

 broad or narrow, entire to coarsely pinnatifid ; disk-flowers brownish-purple ; 

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

 Man. , westw. and south w. ; 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. Receptacle 

 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 dvsudia, an ill smell, which 

 the plants exemplify.) BOEBERA Willd. 



1. D. pappbsa (Vent.) Hitchc. Nearly smooth, diffusely branched, 1-5 dm. 

 high ; leaves opposite, pinnately 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 southwestw. ; occasional as 

 a weed further eastw. July-Oct. 



67. ACHILLEA [Vaill.] L. YARROW 



Heads many-flowered, radiate ; the rays few, fertile. Invplucral 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, finely 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. 



i- Rays comparatively showy, their blades ^ f as long as the involucre ; bracts 

 with dark brown or black margins. 



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

 stem-leaves few (5-9) , silky-lanate especially beneath ; corymbs 2-6 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.) 



-i- ->- Bays small, their blades rarely \ as long as the involucre ; bracts pale, 

 very rarely the uppermost dark-margined. 



3. A. Millef61ium L. (COMMON Y., MILFOIL.) Stem simple or sometimes 

 forked above, 3-10 dm. high, arachnoid or nearly smooth ; stem-leaves numerous 

 (8-15), smooth or loosely pubescent ; corymbs very compound, 6-20 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. lanul&sa Nutt. Similar ; stem 3-6 dm. high, densely woolly ; stem- 



