LESSONS WITH PLANTS 347 



a ripe Russian thistle and note how it rolls before the wind. 

 Note the numerous seeds in the axils of the leaves. 



The tickle grass (panic grass, old witch's broom) breaks 

 off its feathery heads, which are carried away by the breezes. 



In many plants the fruit is provided with special flying 

 or soaring devices. This is well seen in our basswood, elm, 

 boxelder, maples, ash, and in parsley and dock. Throw into 



Fig. 143. The Wing Fruit of the Elm. 



the air sorne of these fruits and see how easily they sail. Some, 

 like the maple and basswood fruits, spin while drifting through 

 the air. This helps to sustain them longer. 



Some plants, hke the clovers, the hop, blue beach, iron- 

 wood, and bladder-nut, have a bladdery envelope around 

 their fruit as a sailing device. 



But perhaps the prettiest and neatest arrangement for 

 sailing is found in the down of many composite plants. The 

 common dandelion, asters, goldenrods, and thistles have 



