WEEDS OF THE THISTLE FAMILY. 15o 



THE THISTLE FAMILY. COMPOSITE. 



Herbs, rarely shrubs, having the flowers in a close head on a 

 common receptacle and surrounded by an involucre of few or many 

 scales or bracts arranged in one or more rows ; leaves varied in form 

 and position; receptacle naked or with chaffy scales, smooth or 

 pitted. Calyx tube of each flower firmly united to the ovary and 

 usually bearing on its summit a pappus of bristles, awns, teeth or 

 scales; corolla tubular, usually o-lobcd or 5-cleft, those of the mar- 

 ginal flowers often split to form a ray; stamens 5, borne on the 

 corolla, their anthers united into a tube. Fruit an achene, con- 

 sisting of the persistent wall of the calyx surrounding a single seed 

 and usually crowned with some sort of a pappus. (Figs. 10, g- 11, 



/, g; 13, 6.) 



A vast family comprising, as above defined, not less than 10,000 

 species of wide geographic distribution. Since the asters form an 

 important group, the members of the family are often called Aster- 

 worts. The name Composites is given to the family from the fact 

 that its members have their small yet perfect flowers densely 

 crowded together into a head, which is enclosed in an involucre or 

 cup formed of several circles of modified leaves called "bracts;" 

 this involucre performing the same protective function for the com- 

 pound mass that the calyx or outer green envelop does for the ordi- 

 nary separate flowers of other families. The object of this massing 

 together of a great number of small flowers into a large head is that 

 they may more easily and certainly attract the attention of insects 

 and thus secure their fertilization. Taken singly, the flowers are 

 too small and inconspicuous to attract separate attention, but by 

 huddling themselves together into a showy mass they have proven 

 themselves very successful plants; so much so, indeed, that the 

 family is by far the largest known in the vegetable world. 



About 205 species of wild Composite} are known from Indiana, 

 194 being listed in Coulter's Catalogue. Among them, besides the 

 weeds described below, are the blazing-stars, golden-rods, asters, 

 everlastings, leaf-cups, rosin-weeds, cone-flowers, sunflowers, worm- 

 woods, Indian plantains and ragworts. It is preeminently a family 

 of weeds as, except from an aesthetic point of view, but three or 

 four of the 200 species are of the least benefit to the inhabitants 

 of the State. The few exceptions are used in medicines, a dose of 

 boneset or yarrow tea being occasionally given by some grand- 

 mother or quack doctor for a fancied ailment. But the lover of 

 nature, whose eye is ever on the search for the pleasing and the 



