REPRODUCTIVE ORGAXS OF PLANTS. 329 



The designation of certain important families of plants 

 is derived from a peculiarity in the form or arrangement 

 of the flower. Thus the pulse family, comprising the 

 bean, pea, and vetch, as well as alfalfa and clover, are 

 called Papilionaceous plants, from the resemblance of 

 their flowers to a butterfly (Latin, papilio). Again, the 

 mustard family, including the radish, turnip, cabbage, 

 water-cress, etc., are termed Cruciferous plants, because 

 their flowers have four petals arranged like the four arms 

 of a cross (Latin, crux). 



The flowers of a large natural order of plants are 

 arranged side by side, often in great numbers, on the 

 expanded extremity of the flower stem. Examples are 

 the thistle, dandelion, sunflower, artichoke, China-aster, 

 etc., which, from bearing such compound heads, are 

 called Composite plants. 



The Coniferous (cone-bearing) plants comprise the 

 pines, spruces, larches, hemlocks, etc., whose flowers are 

 arranged in conical receptacles. 



The flowers of the carrot, parsnip, and caraway are 

 stationed at the extremities of stalks which radiate from 

 a central stem like the arms of an umbrella ; hence they 

 are called Umbelliferous plants (from umbel, Latin for 

 little screen). 



THE FRUIT. 



The Feuit comprises the seed-vessel and the seeds, to- 

 gether with their various appendages. 



Fruits are either dehiscent when the seed-vessel opens 

 and sheds the seed or are indehiscent when it remains 

 closed. 



The seed-vessel, consisting of the base of the pistil in 

 its matured state, exhibjts a great variety of forms and 

 characters, which serve, chiefly, to deflne the differenT; 



