MACHAERANTHERA MATRICARIA 285 



(2) Stems 2-8 in. high, tufted, usually 1-head- 

 ed ; leaves usually spatulate, tapering to 

 the base, not clasping; tips of the bracts 

 broad and flat M. Pattersonii 



b. Bracts of the involucre erect or with flat re- 

 flexed tips shorter than the basal portion; 

 leaves mostly gray-hairy, oblanceolate to 

 linear; stems usually much branched, many- 

 headed, .5-2 ft. high M. canescens 

 2. Leaves 1-3-pinnatifid M. tanacetifolia 



MADIA Molina 1782 TARWEED 

 (From the Chilian name of the common species) 



Heads with yellow pistillate rays, the rays rarely lacking, disk-flowers 

 yellow, perfect, achenes flattened, enclosed in the folded bracts, pappus 

 none; receptacle flat or convex, with a single row of bracts enclosing the 

 disk-flowers, involucre ovoid or oblong, angled by the projecting backs of 

 the bracts ; heads axillary and terminal ; leaves mostly alternate, entire or 

 toothed, sticky; annual. 



Stems 1-2 ft. high; leaves linear; rays 2-5, sometimes 

 none M. glomerdta 



MALACOTHRIX DeCandolle 1838 

 (Gr. malakos, soft, thrix, hair) 



Heads with yellow or white perfect strap-flowers, achenes oblong or 

 linear, ribbed, 4-5-toothed, pappus of hair-like bristles in 2 rows ; receptacle 

 flat, without chaff, involucre bell-shaped, main bracts in 1-2 rows with sever- 

 al rows of shorter ones ; heads solitary or panicled ; leaves alternate or 

 basal, mostly pinnatifid ; annual or perennial. 



1. Achene crowned by a 15-toothed white border M.sonchoides 



2. Achene with an entire crown M. Fendleri 



MATRICARIA Linne 1753 CAMOMILE 

 (Lat, matrix, womb, from its medicinal virtues) 



Heads without rays in our species, disk-flowers yellow, perfect, achenes 

 oblong, 3-5-ribbed, pappus a crown, or none ; receptacle conic or hem- 

 spheric, without chaff, involucre hemispheric, the bracts imbricated in a 

 few rows ; heads solitary on the branches ; leaves alternate, dissected ; an- 

 nual or perennial. 



Stems 6-8 in. high; leaves 2-3-pinnately dissected; 

 heads 6-8 mm. wide M. discoidea 



