CALIFORNIA PLANTS IN THEIR HOMES 



Latin names that botanists have given to the parts of seeds ? 

 Seed-leaves are called cotyledons; the little stem in the seed 

 is the caulicle; the beginning root at one end of it is the 

 radicle; the little bud at the other end, plainly seen in the 

 bean, pea and peanut, is called the plumule; the entire 

 baby plant is called the embryo; when food is stored out- 

 side of the embryo, it is called endosperm; when the embryo 

 begins to grow, botanists say that the seed is germinating. 



The parts of a kernel of corn are not easily made out. 

 The greater part of the kernel is hard and yellow; it 

 shrinks as the seedling grows, and is, clearly, the store of 

 food. Lying closely against this on one side of the kernel 

 is a paler, softer part, and this part is wrapped about a little 

 white rod. When the seed is kept in water for a day or so, 

 you can see that this softer white part swells, and acts like 

 a sponge; that is, it does just what seed-leaves, or cotyle- 

 dons, always do, it absorbs food for the rest of the seed -plant. 

 So we must consider it a cotyledon, although it does not 

 look at all like a leaf, and it always remains below ground 

 with the endosperm. As the seed germinates, the nature 

 of the little white rod is soon revealed. The upper part 

 shoots upward, and is seen to consist of rolled-up leaves, so 

 it should be called the plumule. The stem part, or caulicle, 

 to which the cotyledon is fastened, does not grow rapidly, 

 but at its lower end the radicle lengthens into a main root; 

 side roots are also sent out. Since the stem does not grow 

 up into an arch, the plumule must push straight up through 

 the soil, but the outside leaf protects the rest, and does not 

 attempt to become a foliage leaf itself. When the stem 

 finally comes above ground, notice the circle of staying 

 roots, like tent-ropes. 



The onion seed is very small to study, but it is easy to 

 see that the rolled-up leaves come out as an arch, the tips 

 remaining inside the shell, while the roots grow from the 

 short stem at the base. The onion, like the corn, has one 



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