COMPOSITE FAMILY 



241 



Rays yellow. 



Disk purplish-brown. Rudbeokia, IV 



Disk gray. Lepachys, V 



Disk yellow. 



Involucre of 2 rows of bracts, the outer rather leaf -like. 



Coreopsis, YI 

 Involucre of reflexed scales ; pappus of .5-8 scales. 



Helenium, VII 

 Involucre of erect scales ; pappus of abundant soft hairs. 



Senecio, XI 

 Rays none, but the marginal flowers sterile and their tubular 

 corollas partly flattened like rays. Centaurea, XIII 



Rays none, and marginal flowers like the others; scales of the in- 

 volucre not prickly. Antennaria, III 

 Rays none and marginal flowers like the others ; scales of the in- 

 volucre overlapping in many rows, prickly-pointed. 



Cirsium, XII 



II. LIGULIFLORJE 



Corollas all strap-shaped. 



Corollas blue (rarely pinkish) ; 

 akenes not beaked. 



Cichorium, XIV 

 Corollas blue; akenes beaked. 



Lactuca, XIX 

 Corollas yellow. 



(a) Akenes truncate ; pappus double, 

 of chaff and bristles. 



Krigia, XV 

 (i) Akenes columnar ; pappus of 

 tawny, rough bristles ; stem 

 scape-like . 



Hieracium, XXII 



(c) Akenes spindle-shaped, not 



beaked; pappus of plumed 



bristles. Leontodon, XVI 



I 



Fig. 31. Types of pappus hairs 



A, smooth hair of dandelion ; B, 

 plumose hair of fall dandelion ; 

 C, rough or barbed hair of 

 hawkweed. (7 times natural 

 size) 



