THE AMERICAN BOTANIST 



67 



strength and may often be absent, especially if the leaves have 

 been picked for some time. There are a large number of plants 

 whose leaves when bruised give out an odor. Among these 

 may be mentioned the skunk's cabbage, sassafras, sweet fern, 

 catalpa, lavender, sage and the other mints, but cases in which 

 plants give off odors without being bruised from parts other 

 than their flowers are not so common. The maidenhair spleen- 

 woTt has an odor of this kind and so has the boulder fern 

 (Dicksonia pilosiiisciila) while various tropical ferns exhale 

 much stronger odors. That such emanations ha\'e no connec- 

 tion with pollination is easily understood from the fact that 

 ferns, which never bear flowers, possess them. Probably it is 

 only some by-product of the plant of no more signiflcance than 

 the yellow color of the carrot or the red of the beet. 



Catapult Fruits. — The most conspicuous way in which 

 seeds are distributed is by means of wings. The wings may be 

 on the fruit, as in the maple, ash and elm ; on the seed itself, as 

 in the milkweed, catalpa and trumpet creeper ; or on a bird 

 which eats the juicy pulp surrounding certain seeds and allows 

 the seed to fall to the ground. Another and possibly even more 

 common method of seed distribution is by propulsion, but ow- 

 ing to its inconspicuousness it seldom receives much attention 

 when the subject of dissemination is up for discussion. The 

 witch hazel is the classic example of a fruit which shoots its 

 seeds from the capsule, but there are many other plants that far 

 surpass it in this respect. The sand-box tree (Hiira crepitans) 

 one of the tropical spurges, has a fifteen celled woody fruit 

 larger than a tennis ball which splits into many pieces with a 

 loud report, scattering the disc-shaped seeds in all directions. 

 It may be said in passing that the botanical name for this par- 

 ticular kind of fruit is regnia. In our own New Jersey tea, the 

 seed is often thrown a thousand times its length and some vio- 

 lets may even exceed this performance. There are a vast num- 

 ber of insignificant seed pods that scatter their seeds in the 



