402 SYSTEMATIC BOTAjSTY. 



Class 22. Dioecia, includes plants in which the andrcecium and 

 pistil are in separate flowers, situated on different 

 individuals of the same species, as in the Willow, 

 Hop, and Hemp. {F{gs. 389 and 390.) The name 

 signifies literally two households. 



Class 23. Folygamia. includes plants which have an androecium 

 and pistil, separate in some flowers and united in 

 others, either on the same or on two or three 

 different individuals of the same species, as in some 

 Palms. The. name is derived from the Greek, and 

 signifies many marriages. 



The last class includes all Flowerless Plants, in which the 

 essential organs are said to be concealed ; hence its name 

 Cryptogamia. 



Class 24. Cryptogamia. This includes the Filices {fig. 12), 

 Musci {figs. 8 and 9), Hepaticacese {figs. 811 and 

 813), Lichenes {figs. 821 and 822), Fungi {figs. 

 4 — 6), and Algse {fig. 7), all of which plants are 

 distinguished by being flowerless, and having their 

 organs of reproduction more or less concealed. 



Orders. — The above Classes are subdivided into Orders as 

 follows : — 



The orders in the first thirteen classes, from Monandria to 

 Polyandria, are founded on the number of styles, or of the 

 stigmas if the styles are absent. Their names are derived from 

 a combination of a Greek numeral with the termination gynia, 

 meaning woman or female, and which is used metaphorically 

 for pistil, in allusion to its functions in the process of fertiliza- 

 tion. Thus : — 



Order 1. Monogynia, includes all plants of any of the first 

 thirteen classes, which have but one style to each 

 flower, as the Privet, Speedwell, and Primrose. 

 {Fig. 567.) 



Order 2. Digynia, includes those with two styles, as in most 

 Grasses and Dianthus. {Fig. 588.) 

 * Order 3. Trigynia, includes those with three styles, as Silene 

 and Rumex. {Fig. 636.) 



Order 4. Tetragynia, those with four styles^ as the Holly and 

 Sagina. 



Order 5. Pentagynia, those with five styles, as Flax, Helle- 

 bore, Columbine, Larkspur, and Monkshood. {Fig. 

 425.) 



Order 6. Hexagynia, those with six styles, as Actinocarpus, 

 Butomus, and Drosera. {Fig. 578.) 



