WEEDS OF THE CHICORY FAMILY. 



149 



mite of beauty to the woodland at a time when other flowers are 



scarce. In no place are they numerous 

 enough to be very troublesome and in 

 general they can be kept down by close 

 grazing with sheep, or by mowing and 

 salting. 



Full 300 species of these hawk- 

 weeds are known in various parts of 

 the world, 15 of which occur in the 

 eastern United States. Of these but 

 one, a European species, the golden 

 hawkweed or devil's paint brush (H. 

 aurantiacum L., Fig. 109), is an ag- 

 gressive form but it has not been re- 

 corded from the State. In New Eng- 



Fig.109. Golden hawkweed. (After Clark.) land it j g & ser i US pest in pastures and 



meadows and is spreading westward, having reached northeastern 

 Ohio some years ago. From the rough hawkweed it may be known 

 by having the leaves all basal and the heads nearly 1 inch broad, 

 with the flowers reddish-orange in hue. It spreads by runners as 

 well as by seeds and should be exterminated wherever a single 

 stalk appears. This can be done by grubbing or heavy salting. 



THE RAGWEED FAMILY. AMBROSIACEJE. 



Annual or perennial herbs with alternate, rarely opposite, 

 leaves and small heads of greenish or white flowers surrounded at 

 base by an involucre of few bracts. In our weeds the male and 

 female flowers are in separate heads, the staminate (male) ones 

 above. Female or pistillate flowers without corolla, or this re- 

 duced to a short tube or ring ; calyx attached to the 1-celled ovary ; 

 pappus none ; involucre of the heads bur-like or nut-like. Sterile 

 or male flowers usually with an inconspicuous funnel-form or 

 tubular 4-5 lobed corolla ; stamens 5, separate or nearly so. 



A small family of about 55 species, mostly native of America 

 and many of them weeds. Formerly included with the Composite 

 but, like the dandelions, now separated for convenience. Only 8 

 species, known commonly as ragweeds and cockleburs, are recorded 

 from Indiana. Of these 4 are weeds of the first class. 



114. AMBROSIA TBIFIDTA L. Great Ragweed. Horse-weed. Giant Rag- 

 weed. Kinghead. (A. N. 1.) 



Erect, branched, rough-hairy, $-19 feet high; leaves opposite, stalked, 

 deeply 3-5 lobed, lower often 1 foot wide; upper sometimes undivided, 



