FAMILIAR LESSONS IN BOTANY. 121 



Section III. — Fruit. 



In our talk about the fruit, we forbore crowding your 

 attention with too many divisions; but for your better 

 learning to properly classify, there are one or two things 

 concerning indehiscent fruits that deserve further men- 

 tion. 



You understand that the dry indehiscent fruit of the 

 Ranunculus, which contains a single seed adhering to the 

 pericarp, is called an (28) achenium. Some achenas 

 have a membranous appendage, like wings, as in the elm — 

 it is then called a (29) hey or samara ; others adhere to 

 the pericarp so as to form one body with it — it is then called 

 a (30) caryopsis, as in wheat. 



The dehiscent fruits are distinguished by their manner 

 of opening — some longitudinaUy, as ipesiS and beans; some 

 horizontally, as in the cypress-vine and portulaca ; some 

 open by the severance of the partitions, each valve cor- 

 responding with a carpel — it is then called (31) septicidal 

 deJiisce7ice. Others again open by the dorsal suture, and 

 then the dehiscence is said to be (32) loculicidal, the 

 splitting opening into the cells. 



When the sutures of the pericarp open for a short dis- 

 tance down from the apex, the dehiscence is said to be 

 (35) circumscissile. 



Section IV. — Seed. 



In our talk about the seed, you were told of the embryo, 

 plumule, etc. The outer covering of the seed is called 

 the integument or (34) testa. It yaries greatly. In some 

 seeds it is long, in others membranaceous, and again it is 

 papery. This is closely adherent to the nucleus, and again 

 expanded into wings, as in the seed of the trumpet- 

 creeper. Some seeds, besides this integument, are fur- 

 nished with a covering, partial or entire, made by an 



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