56 PLANT LIFE OF ALABAMA. 



Bay. About one-half are native in the West Indies, Mexico, southern 

 Brazil, and Argentina; one-fourth are arrivals from the Mediterranean 

 region and tropical regions of the Old World, and the rest are from 

 central and western Europe. 



Of the trees and shrubs introduced into cultivation in Alabama a 

 comparatively small number have escaped. Such are rarely found 

 to stray far from the localities where they have been cultivated, and 

 they establish themselves mostly among the native plants along fences. 

 about dwellings, on the borders of adjacent woodlands, and in hedge- 

 rows. Still smaller is the number which have escaped of the orna- 

 mental herbaceous exotic plants cultivated in our gardens. A few 

 spring up voluntarily one season after another within the inclosure, 

 such as Ammi majus, Ageratum mexicanum, Adicea microphylla her- 

 niarioides, but are never found outside of them, while a few others 

 stray into the adjacent fields and waste places, the principal examples 

 being: 



Ipomoea purpurea. Viola tricolor. 



Quamoclit quamoclit. Perilla frulescens. 



Gynandropsis pentaphylla. Gemmingia chinensis. 



More numerous are the escapes from the gardens of potherbs, medic- 

 inal herbs, and otherwise useful plants. Such are: 



Mentha piperita (peppermint) . Cnicus benedictus (blessed thistle) . 



Meniha spicata. Chrysanthemum parthen'min (feverfew) . 



Mentha rotundifolia. Artemisia vulgaris (mugwort) . 



Nepeta cataria (catnip) . Leonurus cardiaca (motherwort) . 



Marrubium irulgare (hoarhound) . Ridnus communis (castor bean) . 



The greatest number of species escaped from cultivation or acci- 

 dentally introduced belong to the grasses, which make up fully one- 

 fifth of the naturalized plants. These are mostly abundant and 

 widely diffused, covering large areas and forming a conspicuous fea- 

 ture among the associations of the indigenous plant. Prominent 

 species are: 



Syntherixma sanguinale (crab grass) . Dactyloctenium fiegyptiacurn (.Egyptian 



Capriola daetylon (Bermuda grass) . crowfoot) . 



Paspalum compressum (carpet grass) . Paspalum dilaiaium (hairy-floweret 1 | as- 



palum) . 



PLANT DISTRIBUTION IN ALABAMA. 



In several instances, the boundaries of the life zones and areas, 

 based upon the distribution of heat and moisture on this continent, 

 as established by Merriam, can not at present be distinctly drawn in 

 Alabama. The investigation of the plant covering of the State, the 

 location of species, and the study of their relation to the factors 

 controlling their distribution within its limits is as yet not sufficiently 



