cistace^: 



37 



The Diamond-backed Moth {Plutella crucifer- 

 aru7ii) belongs to another group, and is much 

 smaller, measuring scarcely three-quarters of an 

 inch across the wings, which are brown, narrow, 

 and fringed; the forewings are bordered behind 

 with a white undulating stripe. The green cater- 

 pillar is extremely destructive to Cabbages, Turnips, 

 etc., wherever it is found, and it has now been 

 carried nearly all over the world. 



Order VII. Resedacece (i genus) 



This is a small family, most numerously repre- 

 sented in the Mediterranean Region, but one or 

 two species are common, chiefly on chalk or lime- 

 stone, in the British Islands, and other parts of 

 Northern Europe. These are the Wild Mignon- 

 ette {Reseda luted) and the Weld (R. luteold). 

 They have pale yellowish green flowers, much 

 resembling those of the Garden Mignonette (R. 

 odorata, originally an Egyptian species), but scent- 

 less. Another species, the White Mignonette 

 (R. suffruticulosd), with nearly white flowers, found 



in sandy places, chiefly in the south, is believed 

 to be introduced. 



The Wild Mignonette has 6 sepals and petals, 

 divided leaves, and most of the petals also divided. 

 The White Mignonette has 5 or 6 sepals and 

 petals, the petals and leaves mostly divided j and 

 the Weld has 4 sepals and petals, the latter partly 

 divided, but the leaves lanceolate and undivided. 

 The peculiar ridged seed-capsule, open at the 

 upper end, is very characteristic of these plants. 

 This capsule is much longer in the Wild Mignon- 

 ette than in the other species. A yellow dye is 

 obtained from the Weld. 



One of the most interesting insects associated 

 with the Resedacece is the scarce Bath White 

 Butterfly, already noticed under Cruciferce. 



Order VIII. Cistacece (1 genus) 



This family, like the last, is chiefly Mediter- 

 ranean. Many are shrubs ; but the few species 

 found in Northern Europe are low-growing plants, 

 belonging to the genus Helianthemum. The best- 



