402 THE SEA SHORE 



Of the interesting order Liliacece we have only one plant of the 

 coast, and even that the Asparagus is not by any means generally 

 common. It is the same plant that is so largely cultivated as an 

 article of diet, and which is so highly valued on account of its 

 diuretic properties. It is moderately common on parts of the south 

 coast, particularly in the Isle of Portland and in West Cornwall, 

 and its general appearance is so graceful that it is largely employed 

 as an ornamental garden plant. The stem is erect and freely 

 branched, bearing feathery bunches of bristled leaves and pale- 

 yellow axillary flowers. As is the case with the Liliacece generally, 

 the flowers are bisexual, with a six-parted perianth, six stamens, 

 and a three-celled superior ovary ; and the last named, in the 

 Asparagus, forms a bright -red berry in the autumn. 



We have now to leave the monocotyledonous plants and pass on 

 to the dicotyledons, which form the most highly developed of the 

 primary divisions of the vegetable kingdom. A few of the general 

 characteristics of this group have already been given, but we must 

 now look rather more closely into the nature of the plants included. 



The class receives its name from the presence of two cotyledons 

 or seed-leaves in the embryo plant, and is also known as the 

 Exogence because the stems increase in thickness by the addition 

 of zones of woody tissue at the exterior. When the young dico- 

 tyledonous plant first appears above the ground, the two cotyledons, 

 which formerly served to shelter the immature bud, usually appear 

 as tiny fleshy leaves ; but these soon wither away, while the bud 

 produces the more permanent leaves that are of a very different 

 structure. A section of the stem will reveal distinct pith, wood, 

 and bark, the wood being more or less distinctly divided into wedge- 

 shaped masses by rays from the pith ; and, in the case of perennial 

 stems, the wood is arranged in concentric rings, the number of 

 which correspond approximately with the years of growth. The 

 leaves of exogens have their veins in the form of a network, and the 

 parts of the flower are generally arranged in whorls of two or five 

 or of some multiple of these numbers. 



The flowers always have stamens and pistil, but in some these 

 organs exist in separate flowers, either on the same plant, or on 

 different plants of the same species, and the ovules are nearly always 

 contained in a case called the ovary. 



Dicotyledons are divided into three main groups, the division 

 being based on the structure of the flowers. They are the Apetalce 

 in which the petals are absent, but the perianth is frequently peta- 



