72 THE INFLORESCENCE. [CHAP. 



14. We cannot fail to have observed the various ways 

 in which the flowers are borne upon the stem, in gather- 

 ing and comparing together the common plants which 

 we have had occasion to use in the course of these lessons. 

 It is convenient to speak of the Flowering System, or 

 mode of arrangement of the flowers of plants^ as the 



INFLORESCENCE. 



In the Tulip we find a solitary terminal flower, borne 

 by a firm herbaceous peduncle, which appears to spring 

 directly from the root. (Such radical peduncles, whether 

 they bear one flower or many as in the Cowslip and 

 Dandelion, are called scapes.} 



In Wallflower, the peduncle, instead of ending in a 

 solitary flower, gives off successively a number of short- 

 stalked (pedicellate) flowers in succession, until it exhausts 

 itself and ceases to lengthen. Such an infloresence is 

 termed a raceme. 



Common Plantain, gathered to feed canary-birds, has 

 a similar kind of infloresence, but the flowers are sessile. 

 This difference distinguishes the spike from the raceme. 



The corymb is a form of raceme in which the lower 

 pedicels are much longer than the upper ones. 



In Cow-parsnip and Carrot the flowers are borne upon 

 pedicels springing apparently from one point. Such an 

 arrangement of pedicellate flowers constitutes the umbel. 

 But as you find each of the umbels in these plants borne 

 upon peduncles, which, like the pedicels, also spring 

 from one point, the entire inflorescence forms a compound 

 limb el ; the umbels of single flowers being the partial 

 umbels. 



Observe the ring of small leaves at the base of the 

 pedicels in the Carrot, forming an involucre. In com- 

 pound umbels we frequently have both general and 

 partial involucres, the former surrounding the compound 

 umbel, the latter each partial umbel. 



Suppose, now, all the flowers of a simple umbel to be 

 sessile ; we should have the same form of inflorescence 

 as we find in the Daisy and Mangold, in which a number 

 of florets are arranged upon a conical or flattened disk 

 (the common receptacle), surrounded by an involucre. 

 Such an inflorescence may be called 2, flower-he ad. The 

 older botanists used to regard the flower-head as a kind 



