11 INTRODUCTION TO BOTANY. 



^ I. The Tlant in general. 



5. Under the common tciTn Plant Lotanists include every being that 

 has rcgitdblc life ; from the lofty forest tree to the moss upon its stem, the 

 mould iness on our decajdng pro\dsions, or the green scum, that floats on 

 stagnant water. 



6. Every portion of a plant which has a distinct office or function to 

 perform in the operations of vegetable life is called an Organ. 



7. The orga)is of plants are of two kinds, the elementary and the 

 compound. 



8. Elenmitarxj organs are those ultimate parts or tissues of which the 

 body of a compound vegetable consists, viz. cellular tissue, woody tissue, 

 and vascular tissue. 



9. Compound organs are formed by various combinations of the elemen- 

 tary, and appear under the form of Root, Stem, Leaves, Flowers, 

 Fruit. Of these the three first, whose function is to assist in the growth 

 of the plant, are termed Organs of vegetation ; and the two last, whose ofiice 

 is the formation of seed, are the Organs of reproduction. 



10. All these compoimd organs, in some shape or other, exist at some 

 period of the life of most, if not all, flotcering 2)lants, technically called 

 phcBuogamous ov phanerogamous plants ; which all bear ^o?m's of more or 

 less complex structure, and are all propagated by seeds containing a germ 

 or embryo plantlet. Flowerless or cryptogamic plants (Ferns, Mosses, Fungi, 

 Lichens, Seaweeds, etc.) have either very imperfect representatives of 

 flowers, or are absolutely flowerless ; and are invariably propagated, not 

 by seeds, but by spores, which do not contain any distinct germ or 

 emhryo. 



11. The elementary organs will be described afterwards ; we shall oon- 

 Bider the compound under the following heads : Eoot, Rootstock, Stem, 

 Leaves, Stipules, Bracts, Inflorescence, Flower, Perianth, Disk, Pistil, 

 Ovule, Eeceptaclo, Fruit, Seed. 



§ 2. The Root. 



12. The primary Root, or descending axis, grows downwards from the 

 base of the stem, divides and spreads in the earth or water, and absorbs 

 food for the plant through the extremities of its branches. 



13. Roots ordinarily produce neither buds nor leaves; their branches, 

 called /i/fs when slender and long, proceed irregulai-ly from any part of 

 theii- surface ; and they increase in length by constant small additions to 

 their extremities. 



14. Though roots proceed usually from the base of the stem or root- 

 stock, they may be formed at the base of any bud, especially if the bud lie 

 along the ground, or elsewhere on the stem, if this is placed in circum- 

 stances favourable for their development. 



15. Roots are 



fibrous, when they consist chiefly of slender fibres ; 

 tuberous, when either the main root or its branches are thickened into 



short, fleshy, or w^oody masses called tt(bers ; 

 tap-roots, -when the main root descends perpendicularly, emitting 



only very few fibrils, as in the Carrot. 



§ 3. The Hoot stock or Ehizome. 



16. The Stock of a herbaceous perennial, in its complete state, includes 

 a small portion of the summits of the previous year's roots, as well as of 

 the base of the previous year's stems. Such stocks will increase yearly so 

 as at length to form dense tufts. They will often preserve through the 



