THE FLOWER 



133 



The Wings (alw), the pair of side petals, of quite different shape 



from the standard. 



The Keel (carina), the two lower and 



usually smallest petals ; these are lightly coa- 



lesoent into a body which liearssome likeness, 



not to the keel, but to the jirow of a boat ; and 



this incloses the stamens and pistil. A Pea 



blossom is a typical example. 



267. Labiate coroUa (Figs. 198-200), which 



would more properly have been called bilabiate, 



that is, two-lipped. This is a conunon form 



of garaopetalous corolla; and the calyx is 



often bilabiate also. These flowers are all on 



the plan of five; and the irregularity in the 



corolla is owing to unequal union of the petals 



as well as to diversity of form. The two 



petals of the upper or posterior side of the 



flower unite with each other higher up than 



with the lateral petals (in Fig. 108, quite to 



the top), forming the upper lip ; the lateral 



and the lower similarly unite to form the lower 



lip. The single notch which is generally found 



at the summit of the upper lip, and the two 



notches of the lower lip, or in other words the 



two lolies of the upper and the three of the 



lower lip, reveal the real composition. So also 



does the alternation of these five parts with those of the calyx outside. 



When the calyx is also bilabiate, as in the Sage, this alternation gives 



three lobes or sepals to the upper and two to the lower lip. Two 



forms of the labiate corolla have been designated, viz. : — 

 Ringent or gaping, when the orifice is wide open (Fig. 198). 

 Personate or masked, when a protulierance or intrusion of the base 



of the lower lip (called a palate) projects over or closes the orifice, 



as in Snapdragon and Toadflax (Figs. 

 199-L'on). 



268. Ligulate corolla. — The ligu- 

 late or strap-shaped corolla mainly 

 belongs to the family of C'oniposita), 

 in which numerous small flowers are 

 gathered into a head, within an involucre 

 that imitates a calyx. It. is well exem- 

 plified in the Dandelion and in Chiccory 

 (Fig. 20.5). Each one of these straps or 

 lignles, looking like so many petals, is 



the corolla of a distinct flower : the base is a short tube, which opens 



204. A pai)iliotiace- 

 ous corolla; 2o:i, 

 front view ; 20-1, the 

 l>arts of the same 

 displayed : s, stand- 

 ard, or vexillum ; 

 T\ wings, or alie; 

 k, keel, or carina. 



205 



