564 BOTANICAL LOCALITIES OR STATIONS. 



squalidus, a little Erophila, and Cheilanthes odora; while on the lime- 

 stone, Acrostichum lanuginosum, was a conspicuous fern. 



The following is a division of plants according to the botanical sta- 

 tions 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 Sea-weeds, Lavers, &c., which are either buried in 

 the ocean, or float on its surface : also, such plants as Ruppia and Zostera. In 

 the Sargasso Sea there are floating meadows of Sargassum bacciferum, 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, glass- 

 wort, Salsola, saltwort, Anabasis. Such plants are often called Halophytes 

 (x f , salt, and <?u, a plant). Under this head may be included littoral and 

 shore plants, such as Armeria, sea-pink, Glaux, and Samohis. 



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

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

 awlwort, Utricularia, bladderwort, Stratiotes. water-soldier, Lemna, duckweed, 

 Pistia, Conferva, Oscil/atorice, and Ranunculus fluviatilis. 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 aquatilis and sceleratus, Polygonum amphibiwn. 

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

 of moisture. Some of these, as Limosella aquatica, grow in places which are 

 inundated at certain periods of the year; others, such as Rhizophoras (mangroves), 

 and Avicennias, form forests at the mouths of muddy rivers in tropical countries. 



B. Land Plants which root in the Earth and Grow in the Atmosphere. 



5. Sand plants; as Carex arenaria, Ammophila arenaria, Elymus arenarius, and 

 Calamagrostis arenaria, which tend to fix the loose sand, Plantago arenaria, 

 Herniaria glabra, Sedum acre. 



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 grasses 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 grain ; as Centaurea Cy- 

 anus, corn 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 iallow ground, as Rumex 

 Acetosella, Carduus nutans, Echium vulgare, Artemisia campestris, and Androsace 

 septentrionalis. In this division, garden weeds are included ; such as Groundsel, 

 Chickweed, Lamium amplexicaule, Chenopodium album, and urbicum. 



9. Rock or wall plants ; Saxifrages, Wail-flower, Linaria Cymbalaria, Draba 

 muralis, species of Hieracium 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. 

 Among them may be noticed, Nettles, Docks, Borage, Henbane, Xanthium. 



