6o8 WEEDS : SPECIAL 



Ragwort, Ragweed {Senecio Jacobcea L.). — An erect perennial 

 with stout, fleshy tap root and smooth stems, growing 2 to 

 4 feet high ; not cottony, or only slightly so. The leaves are 

 pinnatifid or irregularly lobed, giving a ragged appearance to 

 the plant The flower-heads resemble small yellow daisies, and 

 are massed together in a corymbose manner. The fruits blow 

 about like those of groundsel and thistle. 



Abundant in dry pastures and on waste ground when allowed 

 to seed. 



In a young state it is readily eaten by sheep, and by close 

 feeding in early summer, before the stem becomes hard, it is 

 kept in check and rarely seen. 



When its stems have been allowed to grow up, hand-pulling 

 after rain exterminates it. 



Knapweed, Hardhead {Centaurea nigra L.). — An erect per- 

 ennial with tough, hard, grooved stems ; the leaves are lanceolate 

 entire, with rough stiff hairs over them. The flowers are purple 

 and in terminal heads, which are black and hard. They some- 

 what resemble those of a small thistle, but are not prickly. 



The plant is common in meadows and old pastures ; when in 

 abundance it must be hand-pulled to eradicate it. Even this 

 procedure, if done carelessly or in dry weather, is apt to leave 

 pieces of rootstock in the ground which grow again. 



Spear TMstle {Cnicus lanceolatus HofFm.). — A biennial with a 

 strong branching root and stout erect winged stems. The pin- 

 natifid leaves join the wings of the stem and are from six inches 

 to a foot long with long spines upon them ; they are cottony 

 beneath. The flower heads grow at the end of the branches 

 singly and are purple with stiff long spines on the involucre. 



Cutting the first-year plants with a spud, and mowing the 

 second-year plants before the flowers develop and ripen their 

 seeds, exterminates this and the succeeding species. 



Marsh Thistle {Cnicus palustris Hoffm.). — A biennial with 

 winged upright stems, somewhat slender, 2 to 4 feet high, covered 



