224 COMPOSITE FAMILY. 



18. BACCHARIS. Corolla of the pistillate flowers very slender and thread-like ; of the 

 staminate flowers, larger and 5-lobed. Anthers tailless. Akenes ribbed. Pappus 

 in the fertile flower long and abundant; in the staminate, scanty and tortuous. 

 Smooth or glutinous herbs near the coast. 



J H Flowers perfect. 



44. HELIPTEEUM. Flowers with open 5-toothed yellowish corollas. Involucre (silvery 

 rose-colored), smooth obovate, or top-shaped. Akenes woolly ; pappus of numerous 

 plumose bristles. Leaves and stems smooth and naked. 



26. AMMOBIUM. Flowers with yellow 5-lobed corollas, surrounded by a silvery-white 



involucre. Chaffy scales on the receptacle among the flowers. Akenes flattish^- 

 sided ; pappus of 4 teeth, 2 of them prolonged into a bristle. Leaves and stems 

 white-cottony, the latter with leaf-like wings. 



(52) CHRYSANTHEMUM. One species is sometimes rayless, and with flowers all alike 

 from the suppression of the ligulate pistillate ray flowers (p. 226). 



=- Scales of the involucre not dry and scarious or papery (i.e., they wilt) ; flowers 



all perfect. 



I Flowers yellow, with chaff between them; akenes flat, bearing 2-4 awns or bristles. 

 (43, 44) COREOPSIS and BIDENS (p. 227). A few species have no ray flowers. 

 J 1 Flowers yellow, no chaff; akenes not flat ; pappus of copious, very soft and flne, 

 down-like bristles. 



(57) SENECIO. One or two species are destitute of ray flowers (p. 225) ; also (11) SOLI- 

 DAGO (p. 225). | | |j F i owers not y e u ow ; no chaff. 



59. EMILIA. Heads 'rather small, but with many orange-red disk flowers in a very 



simple cup-shaped involucre with no small outer scales. Akenes with 5 acute and 

 hispid-ciliate angles. Very closely related to Senecio (p. 225). 



60. CACALIA. Heads corymbed, with 5-30 white or whitish flowers. Scales of the in- 



volucre a single row, with a few small bractlets at base. Corolla 5-cleft. Branches 

 of the style smooth, with a conical or flat usually minutely hairy tip. Akenes 

 oblong, smooth ; pappus of very many fine and soft, down-like, naked bristles. 

 Leaves alternate. 



(12) BELLIS. A cultivated state with quilled (monstrous) flowers may be sought here 

 (p. 225). 



B. With strap shaped corollas or rays at the margin of the head. (Discoid variations 



may occur.} 



* Herbage, involucres, etc., dotted with large pellucid or colored glands or oil recep- 

 tacles imbedded in their substance, making the plants strong-scented ; involucre 

 of one row of scales united into a bell shaped or cylindrical- cup ; no chaff on 

 the flatfish receptacle; flowers yellow or orange. 



48. DYSODIA. Rays pistillate, mostly short. Involucre with some loose bractlets at the 



base. Receptacle not chafly, but clothed with short chafly bristles. Akenes slen- 

 der, 4-angled ; pappus a row of chafly scales dissected into numerous rough bristles, 

 so as to appear at first sight as if capillary. Leaves opposite. 



49. TAGETES. Rays pistillate. Involucre without bractlets at base. Akenes elongated, 



flat, somewhat 4-sided ; pappus of two or more unequal rigid chafly scales, often 

 united into a tube or cup, sometimes tapering into awns. Herbs, very glabrous. 



* * Herbage not spotted with large translucent or colored, strong-scented glands. 



+- Pappus of copious hair-like bristles ; no chaff on the receptacle among the flowers. 



M- Rays yellow, except in one or two species of Senecio and one Solidago, pistillate. 



= Anthers caudate or appendaged at the base. 



27. INULA. Ray flowers very numerous in one row, with narrow ligules. Outer scales 



of the involucre leaf-like. Pappus of many slender roughish bristles. Akenes 

 narrow. Heads large and broad, the tubular perfect flowers very numerous, their 

 anthers with two tails at the base. Leaves alternate. 



