LESSON 31.] HOW TO STUDY PLANTS. 189 



able to recognize the class and division at a glance. Presently the 

 characters of the great families will begin to fix themselves, and 

 many plants should soon be referred directly to their pioper orders 

 without need of the Analytical Key. 



546. Probably the most difficult plants the beginner will be 

 tempted to analyze are the Compositae, the order to which belong 

 the Dandelion, Sunflowers, Asters, Golden-rods, Thistles, Sage- 

 brush, Groundsels, etc., all those plants with so-called " compound 

 flowers " (277). With many of these forms the difficulty is more 

 imaginary than real, and while in some of the larger genera cer- 

 tain groups of species are very perplexing, most of the species and 

 all the genera can be determined by an ordinarily sharp-sighted 

 observer. To avoid hard places is an exceedingly bad habit to 

 form in analysis, and no group of plants furnishes a better field for 

 careful and satisfactory work than the great family of Compositae, 

 which forms so large and so brilliant a part of our flora. It is ad- 

 visable then for the beginner early to form the habit of regarding 

 the Compositae as proper objects for his study as any of the other 

 orders. 



547. To aid in familiarizing the path through the somewhat for- 

 midable looking Key to the 83 genera of this great order, we will 

 select a very common and early blooming species, the Common 

 Groundsel, or Golden Ragwort, or Squaw-weed, as it is variously 

 called. It grows almost everywhere, in dry, or swampy, or rocky 

 places, and its naked corymbs of bright yellow flowers, and vari- 

 ously shaped and cut leaves, those at the root often differing 

 widely from those on the stem in size and character, make it easily 

 recognized. 



548. With this Golden Ragwort in hand, the student should 

 first bisect vertically the so-called "flower," when he will discover 

 some such arrangement as is figured on page 106, in which the 

 real flowers are shown to be collected in a head, and this sur- 

 rounded by a circle of involucral (205) bracts. It will be noticed 

 that the flowers are of two kinds, the outermost resembling petals 

 (ligulate), the inner ones tubular (277). The ovary (ripened into 

 an akene) is observed to be inferior and surmounted by the copious 

 hairs of the pappus (349), but no chaff (Fig. 220 b) will be found, 

 and hence the receptacle is said to be naked. 



549. Turning now to the Analytical Key (p. ix.), we at once 

 decide that our plant belongs to Series I., PH^ENOGAMIA, under it 



