THE PLANT AND ITS RELATIONS 



The most marked division line in the vegetable kingdom is between the flowerless plants and the 

 flowering plants, the former including all bacteria, yeasts, fungi, algse (to which the sea-weeds belong), 

 liverworts, lichens, mosses, ferns. The demarcation between these two groups is not so marked morpho- 

 logically as it was once supposed to be, and the present tendency is to drop the distinction as respects 

 the flowerless or flowering feature, and to speak of one group as spore-bearing and the other as seed- 

 bearing ; even this distinction is not wholly true, but the morphological phase of the subject does not 

 need consideration here, and the two groups, being natural, may be maintained even if the terminology 

 is tinsatisfactory. The seed-bearers naturally divide into the gymnosperms, in which the ovules are 

 naked (not inclosed in an ovary or pericarp), and the angiosperms, or ovary-bearing plants. The former 

 include the pines, spruces, firs, larches, cedars, yews, and some other woody plants. Geologically, the 

 group is old. The angiosperms comprise all the remainder of the flowering plants, making up by far the 

 larger part of the Conspicuous flora of the earth. 



Pig. 2. 



A fem, one of tlie vascular (or vessel-bearing) flowerless plants. 



on tlie back of a leaf at 0. 



The fruit-bodies, bearing spores, are shown 



The custom has arisen of designating the kinds or species of plants by Latin-form names in two 

 parts, — the first part or word standing for the genus or race-group, and the second part standing for 

 the particular species or kind. Thus, all kinds of true clover belong to the genus Trifolium. The alsike 

 clover is Trifolium hybridum ; the white clover, T. repens ; the common red clover, T. pratense ; the 

 berseem, T. Alexandrinum. Varieties of species, or subordinate forms, are designated by a third Latin- 

 form word, as Trifolium pratense var. perenne, for the true perennial form of red clover. These names 

 are always used with precision for one particular kind of plant, and they afford the only means of desig- 

 nating them accurately. Common or English names are of little service, as now used, in distinguishing 

 species accurately. 



Plants are also assembled in families, which are groups comprising genera that naturally resemble 

 each other in certain bold or general characters. The farmer is specially concerned with the members 

 of some of the family associations. The grass family, or Graminece, includes all the true grasses and the 

 cereal grains, such as maize, wheat, oats, barley, rye, rice ; also, sorghum and sugar-cane. The rose 

 family, Rosacece, contains many of the fruits, — all the stone-fruits and pome-fruits, raspberry, black- 

 berry, strawberry. The pulse family, Leguminosce, comprises the nitrogen-gatherers, — all peas, beans, 

 clovers, vetches, alfalfa. The mustard family, Crueiferm, includes all the mustards, cabbages and kales, 

 rape, turnip and rutabaga, radish. The nightshade family, SolanaeeoB, includes potato, tomato, egg- 

 plant, pepper, tobacco. The rue family, or Butaeex, comprises all the citrous fruits, as orange, lemon, 



