14 THE AMERICAN BOTANIST. 



St. John's-wort as a Weed.— According to Indian 

 Planting and Gardening a shrubby species of St. John's- 

 wort {Hypericum) has taken up its abode in certain 

 Indian grass lands where it spreads so rapidly that it is 

 practically impossible to exterminate it. The tops form 

 dense thickets while the roots continue to ramify through 

 the soil conquering new territory. 



Plants and Ants, — The European species of saw-wort 

 {Serratula) are said to be particularly liable to attack 

 from a certain kind of beetle which destroys their flowers 

 wholesale if allowed free scope. The scales underneath 

 the flower heads of this genus are furnished with glands 

 that exude a liquid and this is much sought after by a 

 species of ant which is selfish enough to drive away the 

 beetle or insect with which it may be able to cope. This 

 custom is of particular advantage to the plants by pre- 

 venting the flower-heads from being destroyed by the 

 beetle. — Gardening World. 



The Arithmetic of Flowers.— Children delight in 

 things they can count and number. I find the mathemat- 

 ics of flowers helps to interest young children in the first 

 steps of botanj^ Beginning with the twos : a common 

 member of the poppy famih% the blood-root, is always 

 noticed by a child during a spring walk. Here he finds 

 two sepals, the petals some multiple of two — either eight 

 or tw^elve — and an oblong pod with two placentae. The 

 Dutchman's breeches is another example of the twos, only 

 not so simple. The threes are shown in the lily and iris 

 families. The trillium is an example ever3^ child will find. 

 Three sepals, three petals, ovary three angled and the 

 leaves in threes. All of the mustards are plainly in fours : 

 four sepals, four petals, four prominate stamens — usually 

 two smaller ones besides — the wild mustards and tooth- 

 wort are familiar examples. The fives are more numerous. 

 The violets, with five sepals, five petals and five stamens 

 are in the hands of every child. The pulse family is also 

 on the plan of five, and the pitcher plant is another inter- 

 esting example. — Mrs. Flora Lewis Marble. 



