VI. THE STEM PROPER 



STEM FORMS AND USES 



Material. — Stems of various kinds — woody, herbaceous, round, 

 square, triangular, jointed, uprigtit, etc. Herbaceous stems are not 

 abundant in winter, but a few hardy herbs like shepherd's purse, dande- 

 lion, winter cress (^Barbarea), dead nettle, or some of the garden 

 biennials can generally be found. Of triangular and jointed stems any 

 of the sedges and grasses will furnish examples. Have young speci- 

 mens of some kind of twining stems raised in the schoolroom. Hop 

 and morning-glory make very good examples. 



201. Woody and Herbaceous Stems. — Aerial stems, or 

 those above ground, are commonly ranked in two general 

 classes, woody and herbaceojcs. The latter are more or less 

 succulent, and die down after fruiting ; the former live on 

 from year to year, sometimes, as in the case of the giant 

 sequoias of California and some of the primitive cypresses 

 of our own southern swamps, even for thousands of years. 

 Many herbaceous stems, like the garden geraniums 

 and the common St. John's-wort, show a tendency to 

 become woody, especially toward the base, and live on 

 from year to year. Woody-stemmed annuals, like the 

 cotton and castor-oil plant are not, properly speaking, 

 herbs. In the tropical countries to which they belong, 

 they are perennial shrubs, or even small trees, but on 

 being transplanted to colder regions, have taken on the 

 annual habit as an adaptation to climate. 



202. Direction and Habit of Growth. — As to manner of 

 growth, there are all forms, from the upright boles of the 

 beech and pine to the trailing, prostrate, and creeping stems 

 of which we have examples in the running periwinkle, the 

 prostrate spurge, and the creeping partridge berry {Mitch- 



143 



