SUPPRESSIONS, ALTERATIONS, APPENDAGES 221 



round the base of the style. In the milkweed (Asclepias} 

 the crown itself is appendaged with five little incurved 

 horns. 



317. Other Appendages. Though appendages are most 

 frequently connected with the calyx and corolla, they may 

 attach to any part of the plant. Figure 377 shows an 

 appendaged anther; and the various appliances for dis- 

 persal furnish examples of appendaged fruits and seeds. 

 When the appendage is so large as to inclose a whole 

 seed, like the loose transparent sac around the seed of the 

 water lily, and the brilliant scarlet pulp around the seeds 

 of the strawberry bush (Evonymous americanus), it is called 

 an aril ; can you think of a use for it ? 



318. Use of Appendages. The offices of these append- 

 ages are as varied as the appendages themselves. They 

 may be, as in the case of hairy filaments, to protect the 

 pollen from crawling insects ; to keep out rain, dew, or 

 frost ; to retain or to shed moisture ; to secrete honey, as 

 in the spurs and sacs of the violet and larkspur, or in 

 other ways to attract and repel insects that aid or hinder 

 the dispersal of pollen. As they are generally the result 

 of special adaptations on the part of the plant to its sur- 

 roundings more particularly with regard to insect polli- 

 nation they are usually indicative of an advanced stage 

 of floral development. 



PRACTICAL QUESTIONS 



1 . Why does a strawberry bed sometimes fail to fruit well, although it 

 may flower abundantly? (310,311.) 



2. Are berries found on all sassafras trees? on all buckthorns? 

 hollies? 



3. Would a solitary hop vine produce fruit? A solitary ash tree? 



4. Why is a mistletoe bough with berries on it so much harder to 

 find than one with foilage merely? (310, 311.) 



5. Explain the nature and use of the appendages in such of the plants 

 named below as you can obtain ; crown of the maypop, jonquil, milk- 

 weed ; spurs of the columbine, tropaeolum, jewel weed, etc. ; bracts of the 

 dogwood and poinsettia ; spathe of Jack-in-the-pulpit and other arums. 



