COMPOSITE FAMILY 241 
Rays yellow. 
Disk purplish-brown. Rudbeckia, 1V 
Disk gray. Lepachys, V 
Disk yellow. 
Involucre of 2 rows of bracts, the outer rather leaf-like. 
Coreopsis, VI 
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, XTII 
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. LIGULIFLORZ 
Corollas all strap-shaped. 
Corollas blue (rarely pinkish); \ / 
akenes not beaked. 2 j 
Cichorium, XIV 
Corollas blue; akenes beaked. 
Lactuca, XIX 
Corollas yellow. 
(a) Akenes truncate; pappus double, 
of chaff and bristles. 
Krigia, XV 
(0) Akenes columnar; pappus of | 
tawny, rough bristles; stem A B C 
scape like piaanen XXII Fic. 31. Types of pappus hairs 
> 
7 A, smooth hair of dandelion; B, 
(c) Akenes spindle-shaped, not ““plumose hair of fall dandelion ; 
healed) pappuk of plumed | [ured tf eines aataal 
bristles. | Leontodon, XVI size) : 
