BOTANICAL LOCALITIES OE STATIONS. 665 



The following is a division of plants according to the botanical 

 stations or physical localities in which they grow, whether placed 

 there by nature or by art : — 



A. — Plants growing in Water, whether Salt or Fresh. • 



1. Marine plants, such as Seaweeds, Lavers, etc., ■which are either buried in 

 the ocean, or float on its surface : also, such plants as Ruppia and Zosteira, grass- 

 wrack. In the Sargasso Sea there are floating meadows of Sargassum bacdferum, 

 gulf -weed. This sea extends from 22° to 36° north lat. , and from 25° to 45° west 

 .long, from Greenwich, and extends over 40,000 square miles. 



2. Maritime or saline plants. These are plants which grow on the border of 

 the sea, or of salt lakes, and require salt for nourishment, as Salicomia, glasswort, 

 Salsola, saltwort. Anabasis. Such plants are often called Halophytes (fiXs, salt, 

 and ifivTiv, a plant). Under this head may be included littoral s.nd .shore plants, 

 such as Armeria, sea-pink, Glaux, sea-milkwort, and Samolus, brookweed. 



3. Aquatic plants, growing in fresh water, either stagnant or running ; as 

 Sagittaria, arrowhead, Nymplwea, water-lily, Potamogeton, pondweed, Subularia, 

 awlwort, UtricMlaria, bladderwort, Stratiotes, water-soldier, Lemna, duckweed, 

 P'istia^ Oonfervce^ OsaiUatoricey and Ranunculus fiuitans. Some of these root in 

 the soil, and appear above the surface of the water ; others root in the soil, and 

 remain submersed, while a few swim freely on the surface without rooting 

 below. 



4. Amphibious plants, living in ground which is generally submerged, but 

 occasionally dry, as Ranunculus aguatilis and sceleratus, Polygonum amphibium, 

 Nasturtium amphibium. The form of the plants varies according to the' degree 

 of moisture. Some of these, as Liirwsella aguatica mudwort, grow in places 

 which are inundated at certain periods of the year ; others, such as Rhizophoras 

 mangroves, and Amcennias, form forests at the mouths of muddy rivers in tropical 

 countries. 



B. — Land Plants which Boot in the Earth and Groxo in the Atmosphere. 



5. Sand plants ; as Carex armaria, Psamma arenaria, Elyrmis arenarius, 

 and Calamagrostis arenaria, which tend to fix the loose sand, Plantago are- 

 naria, Herniaria glabra, Sedum acre, biting stonecrop. 



6. Chalk plants ; plants growing in calcareous and cretaceous soils, as some 

 species of Ophrys, Orchis, and Cypripedium. 



7. Meadow and pasture plants ; as some species of Lotus, bird's-foot trefoil, 

 a great number of gi-asses and trefoils, the daisy, dandelion, and buttercups. 



8. Plants found in cultivated ground. In this division are Included many 

 plants which have been introduced by man along with gi'ain ; as Oentaurea 

 Cyanus, com blue-bottle, Sinapis arvensis, common wild mustard, Agrostemma, 

 corn-cockle, several species of Veronica and Euphorbia, Lolium temulentum. 

 Convolvulus arvensis, Cichorium Intybus ; also plants growing in fallow ground, 

 as Rumex Acetosella, Carduus nutans, Echimn vulgare, Artemisia campestris, 

 and Androsace septentrionalis. In this division garden weeds are included ; such 

 as Groundsel, Chiokweed, Lamium amplexicaule, Chenopodium album, and 



Rock or wall plants ; Saxifrages WaU-flower, Linaria CymJialaria, Draba 

 mwalis, species of Eieracium and Sedum, Asplenium Ruta muraria, and some 

 lichens and mosses. 



10. Plants found on rubbish heaps, especially connected with old buildings. 

 Some of these seem to select the habitations of man and animals on account of 

 certain nitrogenous and inorganic matters which enter into their composition. 



