THE AMERICAN MILKWEEDS 



By Dr. R. W. Shufeldt, C. M. Z. S., Editor of the Department of Wild Flowers 



THROUGHOUT the greater part of the northeastern 

 region of the United States, there are, during the 

 month of January, practically no flowering plants to 

 be found in the woods or in the fields. This is especially 

 true should the winter happen to be a particularly severe 

 one, with little or no snow. However, south of New Jersey, 

 and southward to northern Virginia, it has happened that, 

 during very mild weather, some flowers, as the dandelion 

 for example, have bloomed from late autumn until spring 

 came round once more. The District of Columbia, for 



instance, has experienced a number of such winters within 

 the recollection of those who came into the world during 

 the middle of the last century or earlier. 



As one tramps over the snow-covered fields, or through 

 the silent forests, where the glistening mantle of snow over- 

 lies to a large extent everything that pertains to nature 

 and to earth, flowers are almost the very last things that 

 come into one's head. Still, out in the open, one may meet 

 with things that bring to memory the beaiity of the spring, 

 and summer, and fall months that made up the year which 



DESCRIPTIONS OF GROWING SEEDS 



Figure 10, an oak seed or acorn, with the young oak fairly started. Note 

 that the former is split open, and that the latter consists of the ascending axis, 

 bearing the first leaves, and shooting upwards into the light and air; while 

 below the seed the descending axis, with its rootlets, grows downwards into the 

 ground or soil for nourishment and support, — that is, supporting the plant in 

 its position. Roots, as we shall see later on, are of many kinds; but in no case 

 are they ever jointed, nor do they ever bear leaves. However they may branch, 

 they grow for the most part downwards by extension of their free extremities 

 or ends. On the other hand, the stem or ascending axis grows by a series of joints, 

 which appear in succession, each supporting on its summit from one to a number 

 of leaves. What we see in the young plant is essentially what we see in the full- 

 grown tree, shrub, or plant, only in more marked abundance. In the case of 

 the plants, flowers and other structures are added later on. 



In Figure 11 we have a lengthwise section of an apple seed, which exposes 

 the pair of thick cotyledons within; and in Figure 12 we have the appearance of 

 the latter after they are taken out. I have separated these a little in order to 

 show their form. In these thick cotyledons or embryonic leaves — or seed-leaves as 

 they may be called — is stored the rich food that gives the plantlet its start. 

 The same is seen in a bean (Figure 13) and in an infinite number of other plant- 

 growths. Figure 14 shows a pumpkin seed after it gets a hold upon the ground 

 by its rootlets. Its pair of cotyledons are still giving it nourishment, turning 

 green prior to dispensing their stored food and becoming a pair of true leaves. 



Last month, in Figures 7 and 8, there was shown the nut of the beech tree, 

 both whole and bisected; and here we have, in Figures 15 and 16, the young, 



growing beech tree. As we know, this nut is sweet and delicious, and so rich 

 is it in nourishment that it gives the young beech tree a tremendous start, the 

 earliest stages of which are shown in Figure 15. In Figure 16 these are expand- 

 ed, and the first joint of the plantlet bears its first pair of leaflets aloft. 



One of the best ways to study this most interesting and instructive part of 

 our subject, is to get a box of convenient size and fill it with good soil, which 

 should be kept moist and in a warm place. In this should be planted seeds of 

 a variety of plants and trees, as those of the lemon, corn (Figure21). pea, bean, 

 horse-chestnut (Figures 19 and 20), pine tree (Figures 17 and 18). rice, canary 

 seed, and so on. As germination takes place and proceeds, carefully compare the 

 form it takes on in the different species and seeds; you will find that the cotyle- 

 dons, figured and defined last month, vary enormously in the matter of form and 

 development. Where there are but two cotyledons, the plant belongs to the 

 dicotyledonous group; but when you observe your onion seed, or your grain of 

 corn as it starts to grow, you will note that such forms send up but a single leaf; 

 they are therefore called monocotyledonous. In the case of the pines and the like, 

 there may be from three to five or even ten cotyledons, and when this is the case 

 we term them polycotyledonous. These words are very simple when we know 

 what a cotyledon is; the prefixes dt, mono, and Poly mean but one, two, and 

 many, as they do in so many other words in our language. 



In Figure 17 we have a bisected pine seed, showing the embryo, while the 

 Polycotyledonous young pine tree is shown in Figure 18. In some later issue 

 next year I shall devote a few paragraphs to completing what there is to be said 

 in regard to the germinating seed, the growing plantlet, and their various parts. 



21 



