282 ASTER FAMILY 



Iva Linne 1753 Marsh Elder 

 (Named from Ajuga iva, from its similar smell) 

 Heads without rays, the marginal flowers 1-6, pistillate, disk-flowers 

 greenish, perfect but sterile, achenes obovoid, flattened, pappus none ; re- 

 ceptacle flat, with chaff, involucre hemispheric or cup-shaped, bracts 

 few ; heads solitary or variously clustered ; leaves opposite or alternate, 

 simple ; annual or perennial. 



1. Heads 4-6 mm. wide, solitary in the leaf-axils; 



leaves sessile, oblong to spatulate /. axillaris 



2. Heads 1-2 mm. wide, crowded in panicled spikes ; 



leaves ovate, petioled /. .rant hi folia 



Kuhnia Linne 1753 False Boneset 

 (Named for Kuhn, an American botanist) 



Heads without rays, tube-flowers perfect, cream-colored, achenes ob- 

 long, striate, pappus of feathery, hair-like bristles ; receptacle flat, without 

 chaff, involucre oblong, the bracts striate, imbricated in several rows ; heads 

 in terminal corymbs; leaves alternate, simple; perennial. 

 Stems 1-2 ft. high; leaves linear to lance-ovate, entire 



or toothed; heads 8-16 mm. high K. eupatorioides 



Laciniaria Hill 1762 Blazing Star 



(Lat, lacinia, fringe, from the appearance of the heads) 



(Liatris Schreber) 



PI. 37, fig. 1. 



Heads without rays, tube-flowers rose-purple, perfect, achenes oblong 

 or club-shaped, ribbed, pappus of feathery hair-like bristles ; receptacle flat, 

 without chaff, involucre oblong to ovoid, the bracts imbricated in several 

 rows ; heads in spikes or racemes ; leaves alternate, entire, long and narrow ; 

 perennial. 



1. Heads 3-6-flowered, less than 1 cm. wide as a 



rule; bracts pointed L. punctata 



2. Heads many-flowered, 1-2.5 cm. wide; bracts 



rounded L. scariosa 



Lactuca Linne 1753 Lettuce 



(The Latin name from lac, milk) 



PI. 37, fig. 2. 



Heads with yellow, white or blue perfect strap-flowers, achenes linear 

 to oval, flat, 6-10-ribbed, narrow above or contracted into a beak, pappus of 



