zio THE STRUCTURE OF ECONOMIC PLANTS 



entiation of the sepal primordia, the five staminal primordia arise, 

 each one being opposite a sepal. (Fig. 104, D.) 



The Carpellate Inflorescence and Flower. — The carpellate 

 flowers are borne in short spikes on a more or less compact bushy 

 and leafy shoot. (Fig. 103.) The flowers are closely aggregated 

 at the apex of the inflorescence and are produced in pairs in the axil 

 of a leaf, each flower being subtended by a stipule. (Fig. 105, B.) 

 Commonly one of each pair of flowers is abortive. A short branch 



I-- 



---sti 





w 



D 



\- stp 



Fig. 105. A, transection of apex of carpellate inflorescence, showing arrangement of 

 leaves, stipules, bracts, and flowers ; B, diagram of branch of carpellate inflorescence, showing 

 a pair of flowers ; C, habit of single carpellate flower ; D, longitudinal diagram of carpellate 

 flower, showing floral parts : <7x, floral axis ; if/, floral bract ; /, leaf ; ovy, ovary; our, ova.ry 

 wall ; pth, perianth ; sta p, staminal primordium ; sri, stigma ; stp, stipule ; sty, style. (Re- 

 drawn and adapted from Briosi and Tognini, Istituto Botanico di Pavia.^ 



which arises in the axil of the leaf subtending the pair of flowers 

 bears another leaf with stipules and flowers, and this in turn pro- 

 duces an axillary branch of the third order. (Fig. 105, A.') Since 

 the branches are short, this type of branching results in the forma- 

 tion of the compact carpellate inflorescence. The leaves which sub- 

 tend the paired flowers tend to be in a % phyllotaxy rather than 

 the decussate arrangement of the lower portion of the vegetative 

 axis. 



The carpellate flower is relatively simple in structure, consisting 

 of a pistil surrounded by a transparent, more or less papery perianth. 

 (Fig. 105, C.) In its normal position, the green scabrous floral 



