INDETERMINATE INFLORESCENCE. 



211 



KQ 



383. Before illustrating these, one or two terms, of common oc- 

 currence, may be defined. A flower Avhich has no stalk to support 

 it, but which sits directly on the stem or axis it proceeds from, is 

 said to be sessile. If raised on a stalk, this is called its Pedxincle. 

 If the whole flower-cluster is raised on a stalk, this 



keeps the name of peduncle, or common peduncle (Fig. 

 307, p) ; and the stalk of each particular flower, if it 

 have any, takes the name of Pedicel or partial 

 peduncle (p'). The portion of the general stalk along 

 which flowers are disposed is called the axis of in- 

 Jlorescence, or, when covered with sessile flowers, the 

 rhachis (backbone), and sometimes (as when thick 

 and covered with crowded flowers) the receptacle. 

 The leaves of a flower-cluster generally are termed 

 Bracts. But when we wish particularly to distin- 

 guish their sorts, those on the peduncle, or main axis, 

 and which have a flower in their axil, take the name 

 of Bracts (Fig. 307, b) ; and those on the pedicels or 

 partial flower-stalks, if any, that of Bractlets or 

 Bracteoles {b'). The bracts are often reduced to 

 a minute size, so as to escape ordinary notice : they 

 very frequently fall off Avhen the flower-bud in their 

 axil expands, or even earlier ; and sometimes, as in 

 the gi-eater part of the Mustard family, they altogether ^' 



fail to appear. 



384. A Raceme (Fig. 307, 308, 315) is that form of flower-cluster 

 in which the flowers, each on their own footstalk or jiedicel, are 

 arranged along a common stalk or axis of infloresence ; as in the 

 Lily of the Valley, Currant, Choke-Cherry, Barberry, &c. The 

 lowest blossoms of a raceme are of course the oldest, and therefore 

 open first, and the order of blossoming is ascending, from the bot- 

 tom to the top. The summit, never being stopped by a terminal 

 flower, may go on to grow, and often does so (as in the Snowberry, 

 Shepherd's Purse, &c.), producing lateral flowers one after another 

 throughout the season. In the raceme, the axis of inflorescence is 

 more or less elongated, and the- pedicels are about equal in length. 



385. A Corymb (Fig. 309, 319) is the same as a raceme, except 

 that the lower pedicels are elongated, so as to form a level-topped or 

 shghtly convex bunch of flowers ; as in the Hawthorn, &c. 



FIG. 307. A Raceme, with a general peduncle (p), pedicels (p'), bracts (6), and bractlets (6'). 



