76 SYSTEMATICAL BOTANY. 



I. LINN^AN SEXUAL SYSTEM. 



623. 'This is now disused by men of science ; but, as many 

 books still employed have been arranged upon its plan, it is 

 necessary for a student to understand it. 



624. Its divisions, called classes and orders, depend upon 

 modifications of the stamens and pistils, and have Greek 

 names expressive of their distinctive characters. 



Class 1. Monandria. Stam. 1. 



2. Diandria. Stam. 2. 



3. Triandria. Stam. 3. 



4. Tetrandria. Stam. 4. 



5. Pentandria. Stam. 5. 



6. Hexandria. Stam. 6. 



7. Heptandria. Stam. 7. 



8. Octandria. Stam. 8. 



9. Enneandria. Stam. 9. 



10. Decandria. Stam. 10. 



11. Dodecandria. Stam. 12 19. 



12. Icosandria. Stam. 20 or more, perigynous (359). 



13. Polyandria. Stam. 20 or more, hypogynous (358). 

 Orders. Each of these classes is divided into orders charac- 

 terized by the number of styles or sessile stigmas. Monogy- 

 nia signifies 1 style ; Digynia, 2 ; Trigynia, 3 ; Tetragy- 

 nia, 4 ; Pentagynia, 5 ; Hexagynia, 6 ; Heptagynia, 7 ; 

 Octogynia, 8 ; Enneagynia, 9 ; Decagynia, 10 ; Dodecagy- 

 nia, &c. about 12 ; Polygynia, many. 



Class 14. Didynamia : Stamens 4, two long and two short. 



Orders: 1. Gymnospermia, seeds apparently naked ; 



2. Angiospermia, seeds evidently in a seed-vessel. 

 Class 15. Tetradynamia : Stamens 6, four long and two short. 



Orders: 1. Siliquosa, with a long pod; 2. Sili- 



culosa, with a short pod or pouch. 



Class 16. Monadelphia: Filaments united into a cup or co- 

 lumn. Orders: 1. Pentandria; 2. Decandria, &c. 



as before. 

 Class 17. Diadelphia: Filaments united into two parcels or 



fraternities. Orders : 1 . Hexandria, Sic. as before. 



