IXDEFIN-ITE IXFLORESCENCE. 



155 



or bract from which a secondary floral axis, a", is produced, ending in 

 a single flower, f", less advanced than the flower, /'. This secondary 

 axis bears a leaf also from which a tertiary floral axis is produced, a'", 

 bearing an unexpanded solitary flower, f". From this tertiary axis 

 a fourth is in progress of formation. Here f' is the real termination 

 of the axis, and this flower then expands first, the other flowers being 

 developed centrifugally on separate axes. It is a compound inflores- 

 cence. 



333. indefinite inflorescence. The simplest form of this inflores- 

 cence is when single flowers are produced in the axils of the ordinary 

 leaves of the plant, the axis of the plant elongating beyond them, as 

 in Veronica hederifolia, Vinca minor, and Lysimachia nemorum. The 

 ordinary leaves in this case become floral leaves, by producing flower- 

 buds in place of leaf-buds. In place of solitary flowers there is 

 often an elongated floral axis or peduncle arising from a more or less 

 altered leaf or bract, and bearing numerous leaflets, called bracteoles or 

 bractkts, from which smaller peduncles 

 are produced, and those in their turn 

 may be branched in a similar way. 

 According to the nature of the sub- 

 division, and the origin and length of 

 the flower-stalks, there arise numerous 

 varieties of floral arrangements. When 

 the primary peduncle or floral axis, as 

 in fig. 231 a, is elongated, and gives 

 off pedicels, a", of nearly equal length 

 ending in single flowers, a raceme or 

 cluster is produced, as in Currant, 

 Hyacinth, and Barberry. If the sec- 

 ondary floral axis gives rise to ter- 

 tiary ones, the raceme is branching, 

 and forms a panicle. In fig. 234 is 

 represented a panicle of Yucca gloriosa, 

 of being the primary axis or rachis with 

 bracts, giving off numerous secondary 

 axes, a", which in their turn develop 

 tertiary axes, a"', the development in 



each of the secondary axes being centripetal, and b b b b being the bracts 

 from which the separate axes are produced. If the peduncles in the 

 middle of a dense panicle are longer than those at the extremities, 



Fig. 234. Panicle or branching raceme of Yucca gloriosa. a', Primary axis or rachis. a", 

 Secondary axes or smaller peduncles, a"', Tertiary axes or pedicels bearing flowers, bbbb, 

 Bracts and bracelets, in the axil of which the axes are produced. The inflorescence is indeter- 

 minate, and consists of a series of racemes on a common axis. a'. The expansion of the whole 

 inflorescence is centripetal, and such is also the case with each of the racemes forming it, the 

 flowers at the base of the axes opening first. 



