POETULACAOB^. 445 



(fig. 680), 2-5 valvedj opening ei^er by valves, or more commonly 

 by twice as many teeth as stigmas (figs. 540, p. 303; 681), placenta 

 in the axis of the fruit (figs' '^S, p. 242 ; 681, '2, p). Seeds usually 

 00, amphitropal with mealy albumen, and a peripherioal embryo (fig. 

 682). — Herbs, sometimes suffruticose plants, with opposite, entire, 

 exstipulate, sometimes ' connate leaves, and usually cymose inflor- 

 escence (figs. 270, 271, p. 183).* They inhabit chiefly temperate and 

 cold regions. According to the calculation of Humboldt, Cloveworts 

 constitute -h of the flowering pJsjits of Prance,' ir of Germany, tt of 



, Lapland, and yV of North America. Those found within the tropics 

 are usually met with on high elevations and mountainous tracts, many 

 of them exclusively vegetate in regions of the lowest temperature. 

 The order has been divided into two tribes : — 1. Alsinese, sepals dis- 

 tinct (fig. 293, p. 136). 2. Sileneee, sepals cohering in a tube (fig. 

 297, p. 197). Authors mention 35 genera, and 1000 species. Ex- 

 amples — Alsine, Oerastium, Dianthus, Silene, Polycarpon. 



The plants of this order are usually insipid, but some are said to be 



- poisonous. The poisonous quality is attributed to Saponine, which exists 

 in many of the species oi Saponaria, Silene, Lychnis, and Dianthus. To 

 saponine, also, is due the saponaceous or soap-like properties of the 

 plants. Honkeneja peploides has been used as a pickle. In Iceland 

 it serves as an article of food. The greater part of the plants of the 

 order are weeds, but some are showy garden flowers. To the latter 

 may be referred all the varieties of Dianthus Garyophyllus, Clove-pink 

 or Carnation, Picotees, Bizarres, and Flakes, numerous species of Pink, 

 Campion, etc. The varieties of Carnation depend on the mode in 

 which the coloured stripes or dots are arranged on the petals, and the 

 entire or serrated appearance of their edges. The formation of the 

 placenta in the Caryophyllacese has given rise to discussion, some 

 looking upon it as a marginal, others as an axile formation (p. 243). 



Order 25. — PoETULACApE.a!, the Purslane Family. (Polypet. 

 Hypo-Perigyn.) Sepals 2, cohering at the base. Petals usually 5, 

 rarely wanting, distinct or cohering at the base, sometimes hypogy- 

 nous. Stamens perigynous or hypogynous, variable in number, all 

 fertile, sometimes opposite the petals ; filaments distinct ; anthers 

 versatile, biloeular, with longitudinal dehiscence. Ovary free or par- 

 tially adherent, l-celled, formed by 3 united carpels ; style single or 

 • stigmas several. Fruit capsular, l-celled, opening by circumscissile 

 dehiscence, or by 3 valves, occasionally monospermous and indehiscent. 

 Seeds numerous or definite, or solitary, attached to a central placenta ; 

 albumen farinaceous ; embryo peripherioal ; radicle long. -^Succulent 

 shrubs or herbs, with alternate, seldom opposite, entire, exstipulate 

 leaves, often having hairs in their axils. They are found in various 

 parts of the world, chiefly, however, in South America and at the 

 Cape of Good Hope. They always inhabit dry parched places. They 



