COMPOSIT.E 



629 



LACTUCA SATIVA (Garden Lettuce ) 



Description. Coniiiion garden IclUue is a tall, annual 

 leafy liefh, with a niilk\- juice. There is llirown up from 

 a short stem early in the season a cluster of leaves varying 

 consideralDly in shape, character, and color, in the different 

 varieties. Later in the season, a "seed stalk" is sent up. 

 Tracy found that, at Washington, I). C, the first appearance 



Fig. 255. — Asparagus lettuce, var. angustana. {Aficr CorbcU.) 



of the seed stalk after sowing seed, varied from 59 (in 

 Emperor Forcing) to H2 (in Italian Ice) days. The leaves 

 are alternate, denticulate or pinnatifid, sessile or auriculate- 

 clasping, sometimes spinulose-margined, the lowest ones 

 larc^e, and the upper much smaller. The inflorescence is a 

 panicle. The flowers are yellowish or )-ellowish-white, the 

 involucre cylindric, the bracts of which are imbricated in 

 several series, the outer shorter. 'Hie receptacle is tlat and 

 naked. The corolla rays are truncate and tive-toothed at 



