492 CLASSIFICATIOA\ 



(lorn. The Plant Kingiloni is then divided into a nurnlier e,f 

 subkingdoms as follows: ist, Subkingdom Thallophyta, the 

 thallus plants, including the Alga' and Fungi; 2d, Subkingdom 

 Bryophyta, the moss-like plants, including the Liverworts and 

 Mosses; 3d, Subkingdom Pteridojihvta, the fern-like plants, 

 including Ferns, Lycopods, Ecjuisetum, Isoetes, etc.; 4th, Sub- 

 kingdom Spermatophyta, the seed-plants, including Gymno- 

 sperms and Angiosperms. Subkingdoms are divided into groups 

 of lower order down to the classes. So there are subclasses, 

 subfamilies or tribes, subgenera, and even subspecies. But 

 taking the principal taxonomic di\'isions from the greater to the 

 lesser rank, the order would be as follows: 



Plant Kingdom. 



Subkingdom, Spermatophyta. 



Group (not used in a definite sense). 

 Class, GymnosiX'rmte. 

 Order, Finales. 

 Familv, Pinacete. 

 Genus, Pinus. 



Species, strobus, or, in full, 

 Pinus strobus, the white jjine. 



Group Angiospermae. 



I. CLASS MONOCOTYLEDONES. 



941. Order Pandanales. — Anualic or marsh plants. The 

 cattail flags (Typha) and the Ijur-recds (S]X"irganium), each rep- 

 resenting a family. The name of the order is taken from 

 the tropical genus Pandanus (the screw-pine often grown in 

 green-houses). 



942. Order Naiadales. — Acjuatic or mar.sh herbs. Three 

 families are mentioned here. 



The pondweed family (Naiadacea'), named after one genus, 

 Xaias. The largest genus is Potamogeton, the species of which 

 are known as pondweeds. Rujjpia on identalis occurs in 



