140 THE FLOWER 



flower is stalkless, i.e. sits directly in the axil or other support, it is said 

 to be sessile. If raised on a naked stalk of its own (as in Fig. 241), it 

 is pedunculate, and the stalk is a PEDUNCLE. 



291. A peduncle on which a flower cluster is raised is a common 

 peduncle. That which supports each separate flower of the cluster is a 

 partial peduncle, and is generally called the PEDICEL. The portion 

 of the general stalk along which flowers are disposed is called the 

 axis of inflorescence, or, when covered with sessile flowers, the rachis 

 (backbone), and sometimes the receptacle. The leaves of a flower 

 cluster generally are termed BRACTS. But when bracts of different 

 orders are to be distinguished, those on the common peduncle or axis, 

 and with a flower in their axil, keep the name of bracts ; and those 

 on the pedicels or partial flower stalks, if any, that of BRACTLETS. 



292. A Raceme (Fig. 242) is that form of flower cluster in which 

 the flowers, each on its own foot stalk or pedicel, are arranged along 

 the sides of a common stalk or axis of inflorescence ; as in the Lily 



of the Valley, Currant, 

 Barberry, one section of 

 Cherry, etc. Each flower 

 comes from the axil of a 

 small leaf, or bract, which, 

 however, is often so small 

 that it might escape notice, 

 242^ 243 244 and even sometimes (as in 



the Mustard family) dis- 

 appears altogether. The lowest blossoms of a raceme are of course 

 the oldest, and therefore open first, and the order of blossoming is 

 ascending. The summit never being stopped by a terminal flower, 

 may go on to grow, and often does so (as in the common Shep- 

 herd's Purse), producing lateral flowers one after another for many 

 weeks. 



293. A Corymb (Fig. 243) is the same as a raceme, except that it 

 is flat and broad, either convex, or level-topped. ThaJ is, a raceme 

 becomes a corymb by lengthening the lower pedicels, while the upper- 

 most remain shorter. The axis of a corymb is short in proportion to 

 the lower pedicels. By extreme shortening of the axis the corymb 

 may be converted into 



294. An Umbel (Fig. 244), as in the Milkweed, a sort of flower 

 cluster where the pedicels all spring apparently from the same point, 

 from the top of the peduncle, so as to resemble, when spreading, the 

 rays of an umbrella ; whence the name. Here the pedicels are oome- 

 times called the rays of the umbel. And the bracts, when brought 

 in this way into a cluster or circle, form what is called an INVOLUCRE. 



295. The corymb and the umbel being more or less level-topped, 

 bringing the flowers into a horizontal plane or a convex form, the 



