16 THE BOOK OF NATURE STUDY 



grow into cylindrical branches, which penetrate the soil and 

 expand at their ends into the first tubers. 



THE FOXGLOVE (Digitalis purpurea, L.) 



The Foxglove is one of our showiest and most familiar flower- 

 ing plants, its tall stem bearing numerous purplish red flowers, 

 being conspicuous in June and July in open spots in woods, by 

 hedgerows, and on banks throughout Britain. Along with the 

 plants in flower others will be found which have no elongated 

 flowering shoot, but merely a large rosette of leaves close to the 

 ground. These are plants in their first season, while the flowering 

 plants are in their second year of growth ; both must be examined 

 if an adequate idea is to be formed of the life-history of the plant. 

 The Foxglove is what is known as a " biennial " plant in contrast 

 to annual plants, the life-history of which is completed in a single 

 season, and perennial plants, which live year after year. Its life- 

 history takes two years to complete. In the first year a good 

 sized plant is developed, and by the activity of its leaves a certain 

 amount of food material is stored up ; in the second year the plant 

 grows on into the flowering shoot, and with the production of 

 flowers and fruit the life of the individual is normally over. 



If one of the plants in the first year be dug up and examined 

 it will be found to have a well-developed root-system, consisting 

 of a strong main-root or tap-root from which numerous lateral 

 branches spring. This root-system enables the plant to obtain 

 the water needed to supply the loss from the large leaf surface. 

 The stem of the young plant is short, and bears the leaves, closely 

 crowded into a rosette. The leaves are large and simple. Each 

 is inserted on the stem by a somewhat widened base. This con- 

 tinues into a longer or shorter leaf-stalk, which is grooved above 

 and convex below, while at the sides it thins out into narrow wings. 

 The leaf-blade gradually widens out from the stalk, the thick 

 portion of the latter continuing as the midrib. After increasing 

 in width for about one-third of its length the blade gradually 

 narrows to the tip. The margin is cut into a number of small 

 teeth, at the tip of each of which is a minute pore ; drops of water 

 exude from these pores under certain conditions. The veins form 



