618 _ PHARMACEUTICAL BOTANY | 
HeE.opuytes.—To this group belong plants typical to marshes. 
A Marsh is an area with wet soil, wholly or partially covered with 
water and with annual or perennial herbs (never shrubs and 
trees) which are adjusted structurally to a mucky soil, lacking 
the usual supplies of oxygen. These plants likewise show an 
adjustment to a partial or periodical submergence. Like 
hydrophytes, marsh plants are for the most part perennial. 
They produce adventitious roots and possess horizontal rhizomes, 
or runners, and frequently have air chambers in roots, stems and 
leaves, so that they are adapted to meet the scarcity of air in wet 
soils. They also show a striking development of erect chloro- 
phyll-bearing organs in the shape of leaves, in the flags, and 
stems, in the rushes. 
The taller seed-like plants of the marsh-land, such as seed- 
grass (Phragmites), the bur-reed (Sparganium), the cat-tails ( Typha), 
the blue-flags (Jris), the sweet flag (Acorus calamus) and the 
papyrus (Papyrus) form associations known as fresh-water marshes, 
reed-marshes or fens. The channels or pools of water in among 
these amphibious plants are filled with true aquatic plants. 
_Hatopnytes.—The plants of this group live in a soil which is 
rich in soluble salt, usually common salt (NaCl), and, on account 
of the fact that the osmotic force of the root is nearly inadequate 
to overcome that of the concentrated solution of the soil, the soil 
to such plants is physiologically dry. _A halophyte, in fact, is one 
form of xerophyte. The most striking feature among halophytes 
is that they are nearly all succulent plants. The leaves of such 
plants, for example, are thick, fleshy and more or less translucent. 
They are Tich in concentrated cell sap by which they are able to 
counteract the osmotic pull of the concentrated saline solution 
of the soils in which they live. Anatomically, they are poor in 
chlorophyll; the intercellular-air-spaces are small and_ the 
palisade tissue is more abundant. Coatings of wax are found 
and a hairy covering, although infrequent, sometimes occurs. 
Coriaceous and glossy leaves, especially in tropical halophytes, 
are noteworthy, while in many salt-loving plants the stomata 
are sunken. Halophytes are found in our coastal salt marshes 
and on saline tidal flats in temperate and tropical countries and 
on the alkali flats of the interior of continents. Notable exam- 
