102 TIIK STEM. 



184), to that of a Tree Fern (Fig. 100), and to any persistent, 

 erect or ascending, root-like forms of main stems. 



180. Those stems which are too weak to stand upright, but re- 

 cline on the ground, rising, however, towards the extremity, are 

 said to be decumbent : if they rise obliquely from near the base, 

 they are said to be ascending. When they trail flat on the gi'ound, 

 they are procumbent, prostrate, or running ; and when such stems 

 strike root from their lower surface, as they are apt to do, they are 

 said to be creeping, or repent. They are climbing when they cling 

 to neighboring objects for support ; whether by tendrils, as the 

 Vine and Passion-flower, by their leafstalks, as the Virgin's Bower 

 (Clematis), or by aerial rootlets, as the Poison Oak (Rhus) ; and 

 tivining, or x'oluble plants, when they rise, like the Convolvulus, by 

 coiling spirally around stems or other bodies within their reach. 

 Other modifications of the stem or branches have received particu- 

 lar names, some of which merit notice from having undoubtedly sug- 

 gested several operations by which the cultivator multiplies plants. 



181. A Stolon is a branch wliich naturally curves or falls down to 

 the ground, where, favored by shade and moisture, it strikes root, 

 and then forms an ascending stem, capable of drawing its nourish- 

 ment directly from the soil, and, by the perishing of the portion 

 which connects it with the parent stem, at length acquiring an 

 entirely separate existence. The Currant, Gooseberry, «fec., multi- 

 ply in this way, and doubtless suggested to the gardener the opera- 

 tion of layering ; in which he not only takes advantage of and 

 accelerates the attempts of nature, but incites it in species which do 

 not ordinarily multiply in this manner. 



182. A Sucker is a branch of subterranean origin, which, after run- 

 ning horizontally and emitting roots in its course, at length, follow- 

 ing its natural tendency, rises out of the ground and forms an erect 

 stem. The Pose, the Raspberry, and the Mint aflbrd familiar illus- 

 trations, as well as many other species which shoot up stems " from 

 the root," as is generally thought, but really from subterranean 

 branches. Cutting off the connection Avith the original root, the 

 gardener propagates such plants by division. 



183. A Runner, of which the Strawberry furnishes the most familiar 

 example, is a prostrate, slender branch, sent off from the base of the 

 parent stem, which strikes root at its apex, and produces a tuft of 

 leaves ; thus giving rise to an iudependeut plant capable of extend'- 

 ing itself in the same manner. 



I 



