Ch. VII, 2] 



MORPHOLOGY OF FKUITS 



349 



Fig. 241. — The 

 seed-like fruits 

 (akene,s) of Butter- 

 cup, one in section ; 

 X 5. (From Bailey.) 



dissemination and germination, the ovary wall serving simply 

 as an additional pit-like coat. A very important form of 

 single-seeded indehi.scent fruit is the grain (Fig. 242), dis- 

 tinguished particularly Ijy the fact that seed 

 coat and ovary wall are grown completely 

 together, thus making the structure so seed- 

 like that only the botanist knows its true 

 morphological nature. As its name implies, 

 this fruit is characteristic of the grains, — 

 Corn, Wheat, Oats, etc. Nuts also are 

 commonly one-seeded, though here we meet 

 with morphological complications, both as to the original 

 number of the ovules and the nature of the shell. 



While in general the construction of the fruit answers 

 closely to that of the ovary, some exceptions occur, indicating 

 that the fruit has a certain morphological 

 independence of its own. The development 

 of new dehiscence lines is one instance 

 thereof. The number of compartments, or 

 cells, is usually the same in ovary and fruit, 

 but sometimes partitions disappear, or new 

 ones develop ; while we find also such 

 changes as the formation of four little nut- 

 lets (prevaihng throughout the Mint family) 

 from a two-celled ovar3^ Not infrequently 

 a several-celled ovary produces a one-celled 

 and one-seeded fruit, as in most of our com- 

 mon nuts (Fig. 243), in which an occasional 

 development of a second seed gives us the 

 philopena variety. 



In many cases other parts of the flower 

 persist and are incorporated with the ovary 

 into the fruit, contriljuting to its functional effectiveness. 

 Thus the style, usually deciduous with the petals and 

 stamens, persists in Clematis, where it forms the very con- 

 spicuous plume (Fig. 244). In the Composite family, the 



Fig, 



grain, Oat, in verti- 

 cal section, showing 

 the enibrj^o, R, G, 

 endosperm. A, and 

 the united seed and 

 ovary coat, T ; X 4. 

 (From Le Maout 

 and Decaisne.) 



