6o 



NATURAL HISTORY OF THE FARM 



FIG. 33. The poison hem- 

 lock: portions of flower 

 cluster, leaf and root. 



inedible, and a few like the water 

 hemlock (Fig. 33) are very poison- 

 ous. All the cultivated sorts, radishes, 

 beets, turnips, carrots, parsnips, chicory, 

 etc., are natives of the old world. The 

 last named, where cultivated, is chiefly 

 used to make an adulterant for coffee, 

 and has scarcely any nutritive 

 value. 



American tubers are much more 

 valuable. Indeed, the most valuable 

 root crop in the world is the potato. 

 The potato crop stands among our 

 crops second only to the wheat crop 

 in cash value. And an acre of potatoes may produce as 

 much human food as ten acres of wheat. The only other 

 native tuber that is extensively cultivated is that of the arti- 

 choke (Helianthus tuberosus) which maintains itself 

 wild in great patches in many a rich bottomland thicket. 

 The artichoke is able to win out over the other herbaceous 

 perennials by reason of its sheer vegetative vigor: it over- 

 tops them all and gets the sunlight. And when it blooms, it 

 overspreads the thicket with a blaze of yellow sunflowers in 

 late summer. There is another native tuber, however, of 

 great promise : it 'has higher nutritive value than the potato 

 and is very palatable; it is the so-called groundnut (Apios 

 tuberosa). The plant is a vine, that grows in moist thickets 

 and clambers over low bushes. It bears brownish purple, 

 violet-scented, papilionaceous flowers in dense clusters in mid- 

 summer. The tubers are borne on slender underground 

 stems, often a number in a row, and are roundish or pear- 

 shaped, very solid, and when cut, exude a milky juice, like a 

 sweet potato. Doubtless, this valuable plant, which furnished 

 the Indians with a dependable part of their living, 



