ASTERACEAE 



37 



a. Heads mi a scape 



b. Heads on a leaf) stem 



I I i Pappus branches united by 1; 

 Pappus branches not so united 



Pappus ( apillary 

 \. Achenes Battened 

 (x) Achenes blunt 

 (v) Achenes beaked 

 y. Achenes cylindric or angled 

 (x) Flowers yellow or orange 

 in. Pappus brown or brownish 

 n. Pappus white 

 (y) Flowers white or cream-colored 

 (b) Pappus of blunt scales; flowers blue 



Cynara — Artichoke, ( 'ardoon 



(Or. kinara, artichoke) 



1. Leaves woolly below; head smooth 



2. Leaves smooth ; heads prickly 



Carduus — Thistle 



i I. at. carduus, thistle) 



1. Heads less than .? cm. 



2. Heads more than 3 cm. 



a. Lower surface of leaf brown hairy 



b. Lower >ur face of leaf densely white woolly 

 (1) Leaves usually lobed or dentate 



! ves typically pinnatifid 



(a) Leaves white woolly above 



(b) Leaves green above 





Sonchus 



Hierai ium 



Crepis 



ilus 

 Cichorium 



C. ScSlymus 

 C. cardunculus 



C. arvensis: Canada 

 thistle 



C. lanceoldtus: bur 



thistle 



C. altissimus: tall thistle 



C. unduldtus: I 



thistle 

 C. discolor: field thistle 



Carthamus — Sattlower, False Saffron 



(Ar. qartama, paint, because of the yellow dye it yields) 

 Leaves oblohg-ovate ; flowers orange C. tinctdrius 



Arctium — Burdock 



(Gr. arktion, a plant, from arktos, bear, referring to the burs^ 

 A biennial weed with large ovate leaves ./. lippa 



Laciniaria — Blazing Star 



il.it. lacinia, tear, fringe, referring to the heads) 



1, Iiracts pointed 



a. Heads 15-60-flowered 



(1) Tips of bracts rigid and spreading L. squat 



(2) Tips closely appressed L. cylindracea 



b. Heads 3-6-flowered 



(1) Heads crowded in a long spike; bract tips spreading /.. pyenostdchya 



(2) Heads loose in a short spike; bracts appressed /.. punctata 



2. Bracts obtuse, not pointed 



a. Heads 10 25 mm., 1 S-45-flowered L. scan 



b. Heads 4-8 mm., 5-15-flowered L. spiedta 



Ammobium — Everlasting 



(Gr. ammos. sand, bios, living) 

 Leaves lanceolate, cottony, extending down the stem as wings; heads white A. a' 



