COMPOSITAE (THISTLE FAMILY) 



36 HELIANTHUS, 



1 a Disk flowers purple or brown, especially in older 



flowers ; cultivated species 2 



b Disk flowers yellow 3 



2 a Leaves broadly ovate, rounded at the base; heads 3-18 



in. broad COMMON SUNFLOWER. (H. dnnuus.*) 



b Leaves oblong to lanceolate; heads 2-6 in. broad 



GARDEN SUNFLOWER. (H. rigidus*) 



3 a Upper stem leaves alternate 4 



b Usually all leaves opposite 5 



4 a Upper leaves narrowly lanceolate, usually i in. or less 



broad TALL SUNFLOWER. (H. giganteus.) 



b Upper leaves broadly lanceolate, usually more than i 



in. broad JERUSALEM ARTICHOKE. (H. tuberosus.) 



5 a Leaves usually lanceolate; heads about 1-2 in. broad 



WOODLAND SUNFLOWER. (H. divaricatus.) 

 b Leaves ovate to lanceolate; heads 2-4 in. broad 6 



6 a Leaves usually slender petioled, sharply toothed 



THIN-LEAVED SUNFLOWER. (H. decapetalus.) 

 b Leaves short-petioled, entire or sometimes toothed 



PALE-LEAVED SUNFLOWER. (H. strumbsus.) 



37 CALENDULA POT MARIGOLD. (C. officinalis*) 



38 TAGETES. 



1 a Ray flowers usually 5 DWARF MARIGOLD. (T. signata*) 



b Ray flowers 8 or more 2 



2 a Involucre angular; ray flowers usually of uniform color 



AFRICAN MARIGOLD. (T. erecta*) 

 b Involucre not angular; ray flowers blotched or striped 



FRENCH MARIGOLD. (T. pdtula*) 



39 CALLISTEPHUS CHINA ASTER. (C. hortensis*) 



40 COREOPSIS. 



1 a Ray flowers pink, rarely white 



PINK TICKSEED. (C. rbsea.) 

 b Ray flowers yellow or brown 2 



2 a Lower leaves entire or sparingly toothed or lobed 



LANCE-LEAVED TICKSEED. (C. lanceolata.) 

 b Lower leaves pinnately divided 3 



3 a Cultivated species ; ray flowers often with a brown or 



yellow base or entirely brown, the rays toothed or 



lobed GARDEN TICKSEED. (C. tinctbria*) 



b Wild species; ray flowers entirely yellow, the rays 



entire TALL TICKSEED. (C. tripteris.) 



41 ZINNIA GARDEN ZINNIA. (Z. elegans*) 



42 COSMOS COSMOS. ( C. bipinndtus*) 



43 DAHLIA COMMON DAHLIA. (D. hybrida*) 



235 



