532 



BOTANY OF THE LIVING PLANT 



pollination by flies. The rotate corolla is expanded in a vertical plane, with 

 the style and two stamens projecting horizontally. The insect alighting 

 on the flower gains a foothold by grasping the stamens, drawing them together 

 so that they deposit pollen on the under surface of his body. On going to 

 another flower the stigma receives this, before an additional supply from that 

 flower can be deposited. The result is a high certainty of cross-pollination, 

 with high improbability of self-pollination ; and it is effectively carried out 

 without the three stamens that are abortive. 



ORDER: VERBENALES. 



Family ; LABIATAE. Examples : DEAD-NETTLE, SAGE. 



(40) The Labiatae are a very large Family including herbs and shrubs 

 spread through warm and temperate regions, and characterised by their 



FIG. 438. 



Lamium album. I. flower seen laterally. II. same in frontal view. III. dissection 

 showing ovary and style, and the base of the corolla-tube, with insertion of stamens, 

 and fringe of hairs. IV. ovary as seen from above. V. floral diagram. 



four-angled stamens and decussate leaves. They have often an aromatic 

 smell : Mint, Sage, and Lavender are examples. Their floral structure is 

 very constant. The flowers are either solitary or in axillary cymes. The 

 White Dead Nettle (Lamium album, L.) illustrates the leading features. Its 

 flowers, which are in crowded " verticfllasters," show their cymose arrange- 

 ment by the fact that the flower directly in the axil of the leafy bract opens 



