BOTANY. 



BO'RON. An elementary substance, 

 somewhat analogous to carbon, always 

 found in combination with oxygen as bo- 

 racic acid, from which it was first ob- 



tained by Davy by the action of the 

 voltaic battery. 



BO'RURET. A compound of the ele- 

 ment boron with a metal. 



BOTANY {/3ortivr], a plant). The science which treats of the Vegetable King- 

 dom. 1. Structural Botany relates to the laws of vegetable structure, internal or 

 external, independently of the presence of a vital principle. 2. Physiological 

 Botany relates to the functions of plants and their changes in disease or health. 



3. Descriptive Botany relates to the description and nomenclature of plants. 



4. Systematic Botany relates to the principles upon which plants are connected with, 

 and distinguished from, one another. 



I. SYSTEM OF LINN^US. 



1. Classes.— V\zxii% are distributed into twenty-four classes, founded on the num- 

 l)er, position, and relative connexion of the sexual organs. Of these classes, the 

 iirst twenty have hermaphrodite flowers ; the following three, unisexual flowers ; the 

 last has no flowers. The first eleven classes are founded on the number of the 

 stamens ; the 12th and 13th, on their number and position; the 14th and 15th, on 

 their number and relative length ; the 16th, 17th, and 18th, on modes of connexion 

 subsisting between ihQ filaments of the stamens; the 19th, on connexion of the 

 anthers of the stamens; the 20th, on connexion of the stamens with t\iQ pistil ; the 

 '21st, 22nd, and 23rd, on modifications arising from unisexuality and hermaphroditism', 

 the 24th, on the absence, or obscure nature, of the sexual organs, as compared with 

 those of all the other classes. 



2. Orders. — The classes are distributed into orders, the first thirteen classes being 

 divided, each, into several orders die'^Qw^ing on the number of the styles ; the 14th, 

 into two orders, the seeds, in the one, being covered by a seed-vessel, those in the 

 other being, as Linnaeus erroneously supposed, naked; the 15th, into two orders, 

 the one characterized by a long seed-vessel, or siliqua, the other by a short one, or 

 silicula; the 16th, 17th, and 18th, into several orders founded on the number of the 

 stamens; the 19th, into three orders relating to the unisexual, hermaphrodite, or 

 neutral condition of the florets; the 20th, 21st, and 22nd, into several orders 

 dependent on the number and modes of connexion of the stamens ; the 23rd into 

 three orders founded on unisexuality and hermaphroditism ; the 24th, on general 

 natural affinities. This and the preceding paragraph may be studied in connexion 

 with the tables on the two following pages. 



CLASSES OF THE LINN^AN SYSTEM, 

 •Class 



1. MoNANDRiA 1 iStemew in each flower. 



2. DiANDRiA 2 5towew5 equal in length. 



3. Triandria 3 „ „ 



4. Tetrakdria 4 ,, „ 



5. Pentandria 5 ,, ,, 



6. Hexandria 6 ,, ,, 



7. Heptandria 7 ,, ,, 



8. Octandria 8 ,, „ 



9. Enneandria 9 ,, ,, 



10. Decandria 10 „ ,, 



IJ. DODECANDRIA 12 tO 19 ,, 



12. IcosANDRiA 20 or more, on the calyx. 



13. PoLYANDRiA 20 Or morc, on the receptacle. 



14. DiDYNAMiA 4; 2 long, 2 short. 



15. Tetradynamia .... 6; 'i: long, 2 short', flowers cruciform. 



16. MoNADELPHiA Filaments united at the base into one set. 



17. DiADELPHiA Filaments united into two sets. 



18. PoLYADELPHiA J'i/amen^s United into three or more sets. 



19. Syngenesia Anthers nniiedi. Flowers compound. 



\ 20. Gynandria Stamens mseiiQdi on X\i& Pistil 



56 



