COROLLIFLOR.E 



251 



common on roadsides. Several are used as pot-herbs, 

 such as poodina or Mint {Mentha arvensis), M. viri- 

 dis L., M. piperita L., M. aquatica L., Sage {Salvia), 

 &c. The fragrant oils of some species, as Lavandula 

 (Lavender) (fig. 217), Pogostemon (patchouli) are in 

 great request as perfumes. 



The small flowers are rendered conspicuous from 



Fig. -17. — Lavandula 

 s, Gynobasic style, t, Persistent calyx, w, Enclosed four-lobed ovary. 



being aggregated together in crowded inflorescences. 

 In Octmum, in the first stage of flowering, the stamens 

 curve upwards and the styles curve downwards; in 

 the second stage their positions are reversed, so that 

 the insect-visitors touch either the stamens or the style 

 only, and thus effect cross-pollination. The flowers 

 of Salvia show a wonderful contrivance for securing 

 cross-pollination by bees as described above. Closely 

 allied to Acanthacece, but differs from the latter in the 

 points referred to already under Labiatce. 



