454 SYSTEMATIC BOTANY. 



Sub-order 3. Molluginea, the Carpet-weed Sub-order. — Sepals 

 distinct or nearly so, and alternate with the stamens when 

 the latter are equal to them in number ; if the stamens are 

 fewer than the sepals, they are then alternate with the carpels. 

 ExamfUs : — Mollugo, Cselanthum. 



Distribution and Numbers. — They are natives chiefly of tem- 

 perate and cold climates. When found in tropical regions they 

 are generally on the sides and summits of mountains, com- 

 monly reaching the limits of eternal snow. The order contains 

 about 1,060 species. 



Pro-perties and Uses. — The plants of this order possess no 

 important properties. They are almost always insipid. Some 

 of the wild species are eaten as food by small animals, and some 

 have been said to increase the lacteal secretions of cows fed upon 

 them. This is supposed to be the case more particularly with 

 Vaccaria vidgaris. Saponarla officinalis has been used in syphilis. 

 It contains a peculiar principle called saponine. This principle 

 has also been found in species oi Lychnis, Silene, Gucubalus, and 

 more especially in Gypsopkila Strutkium, to which latter plant 

 it communicates well-marked saponaceous properties : hence it 

 is commonly termed Egyptian Soap-root. The other species 

 in which saponine is found also possess, to some extent, simi- 

 lar properties. Saponine is reputed to be poisonous in its 

 nature. 



Some of the plants have showy flowers, as the species of 

 Dianthus, Silene, and Lychnis ; but they are generally insigni- 

 ficant weeds. Dianthus barbatus is the Sweet-William of our 

 gardens ; D. plumarius is the parent of all the cultivated varie- 

 ties of the Common Pink ; and D. Caryophyllus, the Clove-Pink, 

 is the origin of the Carnation and its cultivated varieties, which 

 are known commonly as Pieotees, Bizarres, and Flakes. 



Natural Order 27. Vivianiaceje. — The Viviania Order. — 

 Characte r. — Herbs or undershrubs. Leaves opposite or whorled, 

 exstipulate. Flowers regular, white, red, or pink. Calyx with 

 5 divisions and 10 ribs; estivation valvate. Petals 6, hypo- 

 gynous, unguiculate, persistent; estivation twisted. Stamens 

 twice as many as the petals, hypogynous; filaments distinct; 

 anthers 2-celled, bursting longitudinally. Ovary superior, 

 3-celled ; stigmas 3. Fruit capsular, 3-celled, with loculicidal 

 dehiscence. Seeds 2 in each cell; embryo curved in fleshy albu- 

 men ; radicle next the hilum. 



Diagnosis. — The plants of this order are readily known among 

 the Thalamifloral Exogens by their regular flowers, valvate 

 10-ribbed calyx, permanent withering corolla, 10 hypogynous 

 stamens with distinct filaments, 2-celled anthers with longi- 

 tudinal dehiscence, 3-celled capsule with loculicidal dehiscence, 



