SECTION 8.] 



INFLORESCENCE. 



73 



201. When flowers tlius arise singly from the axils of ordinary leaves, 

 they are axillary and sOlUari/, not collected into flower-clusters. 



202. But when several or many flowers are produced near each other, 

 the accompanying leaves are 

 apt to be of smaller size, or of 

 different shape or character : 

 then they are called Bracts, 

 and the flowers thus brought 

 together form a cluster. The 

 kinds of flower-clusters of the 

 indeterminate class have re- 

 ceived distinct names, according to their form and disposition. They are 

 principally Raceme, Corymb, Umbel, Spike, Head, Spadix, Catkin, and 

 Panicle. 



203. In defining these it will be necessary to use some of the following 

 terms of descriptive botany which relate to inflorescence. If a 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. 199) it is pedun- 



dilate, and the stalk is a Peduncle. 



204. 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 a 

 Pedicel. The portion of the general stalk ahjng which 

 flowers are disposed is called the Axis of inflorescence, or, 

 when covered with sessile flowers, the Rhachis (liack-bone), 

 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 pedun- 

 cle or axis, and which have a flower in their axil, keep the 

 Xi9.me o^ bracts ; and those on the" pedicels or partial flower- 

 stalks, if any, that of Bractlets or Bracteoles. The for- 

 mer is the preferable English name. 



205. A Raceme (Fig. 200) is that form of flower-cluster 

 in which the flowers, each on their 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, Bar- 

 berry, 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, and even sometimes (as 

 in the Mustard Family) disappears altogether. The lowest blossoms of a 



Fig. 199. Piece of a flowering-stem of Moneywort (Lysiniaehia nunimularia,) 

 with .single flowers successively produced in the axils of the leaves, from below 

 upwards, as the stem grows on. 



Fig. 200. A raceme, with a general peduncle (p), pedicels (/?'), bracts (b), and 

 bractlets {,b'). Plainly the bracts here answer to the leaves in Fig. 199. 



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