54 PLANT 1,1 I'K <'!• A I, A ISA MA. 



It is ot'tcii iiii|t(f->il>l(' to drcidi' w lict Ikt :i plant >lii Mild I ir considered 

 iiat urali/.ed or nati\c. part ieularly wlirn. tlioiiti'li it n'rows in distant 

 jKirts of tlie ^lolie. every tiaic is olditerated ol" the time :ind niannei- 

 in which it niav hii\e been Int rodue«'d. Such instances arc found in 

 tht> ( 'herokee rose (linsti lih i'i(f((tii), tile eonmion t^cmrd {Ldfjenaria im/- 

 </''/v.\). and the th<)rna|)))h' {Ihilnra si nuiitnuiiin). I'he first, also at 

 lioine in eastern Asia, is said to ha\'e been found hy the wljites on 

 their liist arrival at t he \illaL;»'s of the ( "herokcM's and ('recks; the sec- 

 ond, dispei'sed o\-er the warmer I'cg-ions of the Old World, was frc- 

 (|uent]y found al»out the hal)itations of the aborij^ines in the wai'mcr 

 temperate and siibti'opical /one of this continent. aii<l the last was met 

 with about the Indian \ illau'cs on the ])anks of the dames River in 

 Virgiina. 



A I )VENTI V !■; PLANTS. 



Thes(> arc forciofu plants which have i>-aincd a firm foothold only on 

 cultivated lands, or land abandoned by the cultivator, and aic rarcd}' 

 found to stray beyond the waste places near his dwelling, lacking 

 power to hold their own in the struggle with the indigenous plants for 

 the possession of the soil. Strong feeders, of quick growth, these 

 adventive plants are dependent upon soils rich in available nitrog- 

 enous plant food, such as is provided by the tiller of the soil for liis 

 crops or is accunudated in the rubbish about his habitations. Here 

 belong the host of weeds which infest fields, gardens, and meadows, 

 and consequently are in close connection with the cultuial plant 

 formations. 



If it is diificult to draw the liiu^ l)etween naturalized and indigenous 

 pljints, it is not less so to decide Avhether a plant is thoroughly natu- 

 ralized or merely adventive. Some of the species, at first merely ad- 

 ventive, acquire speedih' the ability to accommodate themselves to 

 their changed environment and thus l)ecome aide to gain a firm hold 

 upon the soil among the indigenous plants, not infrequently spreading 

 widely if the proper opportunities for their dissemination exist. Some 

 of the plants of (juite recent advent from distant shores offer striking 

 examples of this kind. The Japanese clover {Lcsjjedesa sti'lata)^ advent- 

 ive from eastern Asia, and first observed at the port of Charleston, 

 S. C , during the second quarter of this century, has noAV spread over 

 thousands of square miles, west to Louisiana and southern Arkansas, 

 and as far north as Maryland. This enormous spread was speedily 

 effected by the droves of cattle and horses following the armies during 

 the late war. Greedil}' eaten by the animals, the seeds l)eing voided 

 without being injured and readily germinating in the decaying drop- 

 pings, this annual was soon permanently established in the open 

 woods and pasture lands, over hill and lowland, throughout a vast 

 extent of country. The bitterweed {Ilelenium tenuifolium)^ originally 

 from the sunn}' plains w'est of the Mississippi River south of the 



