54 PLANT LIFE OF ALABAMA. 
It is often impossible to decide whether a plant should be considered 
naturalized or native, particularly when, though it grows in distant 
parts of the globe, every trace is obliterated of the time and manner 
in which it may have been introduced. Such instances are found in 
the Cherokee rose (Rosa laevigata), the common gourd (Lagenaria vul- 
garis), and the thornapple (Datura stramonium). The first, also at 
home in eastern Asia, is said to have been found by the whites on 
their first arrival at the villages of the Cherokees and Creeks; the sec- 
ond, dispersed over the warmer regions of the Old World, was fre- 
quently found about the habitations of the aborigines in the warmer 
temperate and subtropical zone of this continent, and the last was met 
with about the Indian villages on the banks of the James River in 
Virginia. 
ADVENTIVE PLANTS. 
These are foreign plants which have gained a firm foothold only on 
cultivated lands, or land abandoned by the cultivator, and are rarely 
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 his 
crops or is accumulated 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 cultural plant 
formations. 
If it is difficult to draw the line between naturalized and indigenous 
plants, it is not less so to decide whether a plant is thoroughly natu- 
ralized or merely adventive. Some of the species, at first merely ad- 
ventive, acquire speedily the ability to accommodate themselves to 
their changed environment and thus become able 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 quite recent advent from distant shores offer striking 
examples of this kind. The Japanese clover (Lespedeza striata), advent- 
ive from eastern Asia, and first observed at the port of Charleston, 
S. C., during the second quarter of this century, has now spread over 
thousands of square iniles, 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. Greedily eaten by the animals, the seeds being 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 (Helenium tenuifoliim), originally 
from the sunny plains west of the Mississippi River south of the 
