The Forms of Flowers. 



89 



Fig. 68. Bilabiate corollas. 



panula, with leaves spreading but curving toward the axis, 

 make ccimpanulate flowers ; the recurved perianth of a tiger- 

 lily looks like a turban; the incurved one of a common 



white calochortus is nearly globular 

 or ovoid (Fig. 66), and the strongly 

 infolded petals with the widely 

 spreading sepals of another yellow 

 species give a remarkable form. 



Fig. 67 shows common forms of 

 corollas with united petals. A co- 

 rolla or calyx is tubular if its parts 

 are united nearly to the ends into a slender scarcely widen- 

 ing tube with erect lobes. If the limb is rotate and the 

 tube slender so as to make the 

 flower look like a salver it is 

 salverform. 



Irregular flowers usually 

 have the upper pair of petals 

 different in shape and size from 

 the side pair and the lower one. 

 When the petals are united the 

 upper pair forms the upper lip 

 and the other three the lower 

 Up of a bilabiate corolla. Figures 68 and 69 show some of 

 the many hundreds of forms of bilabiate flowers.* 



* Orchids, of which there are nearly three thousand kinds, mostly natives of the 

 tropics, all have irregular flowers. One petal called the lip is often very different 

 from the others in size and form (Fig. 70). All are adapted to insects, and only 

 a few can produce seed without their aid. There are on this coast less than thirty 

 kinds, mostly with small flowers. 



Fig. 69. Bilabiate corollas having 

 elongated galea. a and b have the 1 wer 

 lip reduced to three tooth-like projec- 

 tions, d. The corolla and c the entire 

 flower of a rose-purple orthocarpus. 



