122 



WEED FLORA OF IOWA 



Fig. 69-A. Distribution of Chickweed. 



or oblong, from % to 2 1 /? in. long, lower leaves on hairy petioles, 

 sepals 4 or 5, greenish ; petals 4 or 5 ; shorter than the calyx and 

 2-parted; stamens 3-10; styles 3. Pod ovoid. 



Distribution. — Chickweed is widely distributed in the northern 

 states to the Pacific coast ; naturalized from Europe ; common in 

 many places in lawns and in shady places, not especially trouble- 

 some except on the lawn, where often it runs out blue grass. 



Extermination. — This weed is easily exterminated by cultivation. 

 Since the lawn, however, cannot be cultivated the best and most ef- 

 fective means of exterminating the weed is to spray with iron sul- 

 phate at the rate of 100 pounds to a barrel of water. Spray as soon 

 as the plants make their appearance and repeat 2 to 5 times during 

 the season. 



Nodding Chickweed (Cerastium nutans Raf.). 



Description. — A clammy, pubescent, much-branched annual with 

 slender, erect stems 6-20 in. high ; leaves oblong, lanceolate, acute, 

 the lowest spatulate ; flowers numerous in open loose cymes ; pods 

 nodding on the stalks, curved upward, larger than the calyx. The 

 larger mouse-ear chickweed (Cerastium viscosum) is a perennial 

 with obovate, clammy, hairy stem ; leaves varying from oblong to 

 lanceolate ; flowers clustered at first ; sepals rather obtuse, small. 



The common mouse-ear or chickweed (C. vulgatum) is a peren- 

 nial with clammy pubescence. 



Distribution. — From New England to Minnesota, especially south- 

 ward in southern Iowa and Missouri. 



