ap. 
AS 
* 
ee 
/% Leaves not deltoid, acnenes not as described 
/8 Heads 1-4 cm. tall 
2oueads GS-4 cm. tall; bracts herbaceous; 
24 flowers purple a4. Zudbeciia 
= 
Zo Heads 1 cme tall or less; bracts papery; 
2a flowers crecnish-yellow 
0 Matricaria 
/?@ Heads 5-6 ma. tall 
ZO Heads all similar, the flowers a11 fertile; 
bracts not wnited to vorm a cunr-like 
&4 \ involucre 
pPeoueads in elongate panicles or 4) 
peers | 
2p deads in flat-toppeu or convex corymbs 
24 Leaves crenately toothed 
a4 Leaves tinnatifia 39. fanace twa 
ZO Heads of two kinds, the staminate 
pendulous in racemes, with cup-shayed 
involucres of coalesced bracts, tne 
pistillate borne below the staminate in 
CA' the upper axils, inconspicuous, 1-flowered, 
the involucre completely investing the 
flower and achene 32.. Ambrosia 
Strap-shaped ray-flowers present 
a ¥a.tay flowers blue, pins, purple or Waite, not yellow 
(, Faprus of nairlike bristles; leaves entire or 
jomerely toothed (except Brigeron compositus) 
& Involucral bracts in £-35 series, rarely 4, 
12 their tics thin ana scarious; ray-corollas 
* \l ma. wide or less With one exceytinon J@- sriceron 
& Involucral bracts in several series, usually 
unequal, their tions commonly nerbacecus 
3 
“ ‘ yr a ron a) at <r mya +4793 ahaa sine Late 
“ \ray-corollas mostly more than 1 wm. wide j§, Aster 
& Papous none; leaves vinnately lobed or aiviaed 
a) Tre 27) new ae 1. 35+ Aas ac Tisr a7 aap ft , - 
@ Disc-flowers each subtendea by an erect bract, 
5, Ee ere Papen Maa ad , + rs 4 ee 
i%the recertacle tnererore cnari? 
a he N ba) u id yo t4 r 4 oy > Wa wyoye Sana 
io .chenes flattened, smooth, tne margins 
j 4 sh A= rar 
i LoLOi.Guea 
39. Chrysantnenun 
