ST 'X FLOWER FAMILY. 



483 



KEY TO THE TRIBES. 



Heads composed wholly of perfect flowers with ligulate corollas; ligule 

 5-toothed at apex; herbs with milky juice; leaves alternate or radical. 



L Cichorie*:. 



Heads composed of ray- and of disk-flowers or of disk-flowers only. 

 Receptacle covered with bristles; heads large; flowers conspicuous; 

 corollas cleft into long narrow lobes; rays none; very spiny thistles 



or thistle-like plants; leaves alternate 2. Cynare^e. 



Receptacle with chaffy bracts (see also nos. 28 and 29). 

 Rays always present, conspicuous or inconspicuous; disk-flowers perfect; 

 bracts of the involucre foliaceous or herbaceous, not scarious; pappus 

 of paleae or awns, never capillary. 

 Involucre of 1 series of equal bracts, each embracing or enfolding a 

 ray-achene; bracts of receptacle often in a single series between 

 ray and disk; leaves alternate or opposite; (annuals except two). 



6. MADIE.fi. 



Involucre of 1 to several series of bracts, none enfolding ray-achenes; 

 receptacle very chaffy; leaves mostly opposite or radical 



7. HELIANTHEiE. 



Rays none; leaves alternate (except no. 69). 

 Heads unisexual (except no. 63), small, greenish or white; corolla of 



Sistillate flowers none or a rudiment; anthers nearly or quite 

 istinct; pappus none; fruit usually a bur; leaves alternate (the 



lower opposite in no. 63) 8. Ambrosie^;. 



Heads composed of both pistillate and staminate (or perfect) flowers; 

 corolla of pistillate flowers filiform; bracts of the involucre few 

 or none; leaves alternate (except no. 69); white-woolly annuals. 



9. Inule^e. 



Receptacle naked (without bristles or chaffv bracts, except nos. 28 and 

 29); leaves alternate (except nos. 26, 36, 37, 38, and 91). 

 Bracts of involucre in 1 or 2 series; pappus of soft capillary bristles; 



both disk- and ray-flowers yellow (except no. 23). . . 3. SenecionejE. 

 Bracts of involucre imbricated, dry and scarious; pappus none or 

 reduced to a mere crown or ring; flowers white, yellow or greenish; 

 rays present or absent; leaves usually much divided 



4. ANTHEMIDEiE. 



Bracts of involucre in few series, little imbricated; pappus paleaceous, 

 awn-like, bristly or none; flowers yellow; rays present (except in 

 no. 42) 5. Heleniea:. 



Bracts of the involucre many and imbricated, often dry or scarious; 

 pappus of capillary bristles; rays none; pistillate corollas mostly 

 filiform; (pappus none and bracts few in no. 75) . 9. Inule«. 



Bracts of involucre well imbricated; disk-flowers commonly yellow, the 

 rays of the same or different color or none; pappus of awns or 

 bristles (or of short scales in no. 76) 10. Astere*. 



Bracts of the involucre equal or imbricated ; flowers perfect, white or 

 whitish; rays none 11. Eupatorie.e. 



Tribe 1. Cichorieae. Chicory Tribe. 



Herbs with milky juice and alternate or radical leaves. Receptacle 

 naked or with chaff-like bracts. Flowers all perfect and all with 

 ligulate corolla, the ligule 5-toothed at apex. Anthers sagittate or 

 auricled at base, commonly appendaged at summit. Style-branches 

 stigmatic on their inner side for their whole length. 



A. Pappus paleaceous or of rigid bristles. 



Pappus paleaceous, the paleae without awns; achenes neither ribbed nor 

 beaked. 



Flowers blue; receptacle naked; herbage soft . . . 1. CiCHORirM, p. 490. 

 Flowers vellow; receptacle with chaff-like bracts; thistle-like plant . . . 



2. Scolymtjs, p. 490. 



