COMPOSITACEAE (COMPOSITE FAMILY) 223 



Y. Involucre bracts in more than 2 indistinct whorls; rays unequal, wider than 



filiform, in i whorl; pappus in i whorl. (Gk. aster = a star; referring to the 



radiate heads of most species.) Aster (ASTER) 



YY. Involucre bracts in 1-2 indistinct whorls, usually nearly equal; rays mostly 



filiform, in i or more whorls; pappus in 12 whorls, the outer whorl often of scales 



or shorter bristles. (See QQ.) Erigeron (FLEABANE) 



XX. Involucre bracts white, green-tipped; rays about 5, white; akenes not or 



hardly flattish. W. (Gk. serikos = silky, karpos = a fruit; referring to the 



hairy akenes.) Sericocarpus rigidus (WHITE-TOPPED ASTER) 



GRINDELIA (GUM-WEED) 



Herbs, often gummy specially on the involucre, coarse. Leaves alter- 

 nate; stem leaves sessile to clasping. Ray flowers none or in i series; 

 corolla yellow. Disk flowers perfect; corolla yellow. Pappus of 2-8 

 nearly smooth and easily separating awns or bristles. (Honor of D. H. 

 Grindel, a Russian botanist.) Sometimes a bad pasture weed. 



A. Stem leaves widest at their base, acute or acuminate; heads radiate, more than 

 15 mm. high. W. G. integrifolia 



AA. Stem leaves narrowed at their base, obtuse in most. 



B. Heads more than 15 mm. high, radiate; plant glabrous or sparingly hirsute. W. 



G. oregana 



BB. Heads 10-15 mm. high, radiate or rayless; plant glabrous throughout or slightly 

 chaffy. W. C. E. G. nana 



INULEAE (Elecampane Tribe). Herbs. Leaves entire (except Inula). 

 Heads not radiate (except Inula). Involucre usually dry and scarious. 

 Pistillate flowers mostly filiform and truncate. Anthers tailed at base 

 (except Dimeresia and Adenocaulon) . Style branches naked, obtuse to 

 truncate, unappendaged. Pappus none or of capillary bristles. 



A. Heads less than 2 cm. wide, rayless; basal leaves smaller than in AA; leaves often 



white-woolly. 

 B. Leaves linear to oblong or obovate, not cordate at base, often woolly on both 



sides. 



C. Leaves alternate. 

 D. Pappus none, except a few bristles on sterile flowers. 



E. Style and corolla lateral; plant simple or sparingly branched above, loose- 

 woolly. U. (Gk. micros = small, pous = foot; application not clear.) 



Micropus californicus 



EE. Style and corolla terminal; plant branching from the base, appressed- woolly. 

 U. (Gk. stylos = a column, kline = a bed; referring to the receptacle.) 



Stylocline filaginea 

 DD. Pappus of capillary bristles. 



F. Involucre bracts many and white throughout, conspicuous and almost hiding 

 the small group of yellow flowers within. W. C. E. (Gk. a = not, knaphalon 

 = a lock of wool; because the heads are chaffy rather than woolly.) 



Anaphalis margaritacea (PEARLY EVERLASTING) 

 FF. Involucre bracts either few or not white throughout, not so conspicuous as 



the group of flowers within. 



G. Heads dioecious or sometimes the 2 kinds on the same plant; pappus bristles 

 of the staminate flowers swollen at tip. (The pappus bristles of the sterile 

 flowers suggested the antennae of insects.) Antennaria (EVERLASTING) 



