68 PRACTICAL BOTANY. 



uppermast one, wliicli is visually the largest, is called 

 vexillum (banner; standard), the two lateral ones wings 

 (alse), and the two lowest, which are often nnited at their 

 lower margin, the keel (carina) (PI. V., 3«) ; orchidaceous, 

 having, within three sepals, three petals, whereof one, the 

 lip, which, in fact, is uppermost, but apparently, by tlie 

 twisting of the ovary, lowermost, is variously enlarged and 

 deformed. (PI. XIII., 12.) 



134. Certain appendicular organs of the flower are 

 called spurs, scales, glands, crown. 



These are good marks not to be overlooked, when we 

 want to' identify certain plants. All these appendages 

 were formerly comprehended under the general name of 

 I^ectary. 



Spurs are more or less elongated tubular appendages of 

 the flower, usually projecting from behind it. Aquilegia 

 has all its petals spurred (PI. III., 4), the Violet only one 

 (PI. IV., 2), and Delphinium two of its petals and one 

 of its sepals, the spur of the sepal enclosing the spurs of 

 the petals (PI. III., 5). 



Scales are attached either to the throat of the corolla, as 

 in certain Borrageworts, or to the claws of the petals, as 

 in Buttercups. 



A Crown is an appendage at the summit of the claw of 

 some petals, as in Silene and Soapwort. 



Olamdular bodies arc often met with on the receptacle ; 

 they are abortive organs of one kind or another. 



133. The arram^ement of the floral leaves {perianth) 

 in the hvd is called ^Estivation. In identifying plants, 

 we must not overlook it. 



We distingviish four principal modes of aestivation — 

 namely, the val/vate, plaited, contorted, and imhricated. 

 They take place in the calyx as well as in the corolla. 



