LESSONS IN BOTANY. 233 



sagitate and partly clasping. The pod of the mustard is a 

 silique. 



Many of these plants, as the radish, are biennials, that is, they 

 grow from the seed during one season, storing up in the roots 

 some nourishment for the next season. During the second sea- 

 son they produce flowers, mature seed and die. Many plants 

 live only one season, dying as soon as seed has been matured. 

 Such plants are called annuals, while trees arid many others live 

 on from year to year and are called perennials. 



The Violacese or Violet Family. The members of this family 

 are well-known plants, highly prized for their beautiful flowers. 

 The flower is irregular, with five sepals and five petals, which are 

 more or less unequal, the lower one with a sack or spur at its 

 base. The stamens are five, the broad, flat filaments, slightly co- 

 hering around the pistil. The somewhat showy flowers are sel- 

 dom fertile. Another set of flowers, hidden under the leaves, 

 produce most of the fruitful pods. These flowers are of a green- 

 ish color, and are more nearly regular than the more conspicuous 

 ones above. The irregularity of the aerial flower is supposed to 

 have some relation to insect a,gency in fertilization. Some of the 

 violets send up flower stalks from underground stems, and some 

 have aerial stems. This is a very interesting flower from its 

 various irregularities, and a careful study of it according to the 

 plan followed with the trillium would be a valuable and inter- 

 esting work. 



The members of the Droseracese or Sundew Family are inter- 

 esting chiefly from the fact that they are carniverous or insect 

 eating plants. They are bog plants with regular flowers, on the 

 plan of fives, having a tuft of glandular bristly leaves at the base 

 of the stem, which in the bud are rolled up from the apex, alter 

 the manner of ferns. The common sundew has small roots with 

 five or six root leaves spread out in a rosette around the base of 

 the stalk. The upper surface of each leaf is covered with gland 

 bearing filaments, each of which is crowned by a drop of a trans- 

 parent viscid secretion. Insects are attracted to these leaves, 

 and lighting on them are entangled by the secretion of the ten- 



