150 



< itoGRAPHY. Exclusively confined to the northern hemisphere, and even 

 to its eastern half, that is, to the old world, on which they extend as far as the 

 Cape de Verds. They usually grow b}* the sea-side, but occasionally by the 

 edges of rivers and torrents. The maximum of species and of individuals also 

 is found in the basin of the Mediterranean. The order appears bounded on 

 the south by the 8° or 9° parallel of N. lat., and on the north by that of 50° 

 and 55° in Siberia, Germany, and England. Ehrenb. 



Properties. The bark is slightly bitter, astringent, and probably tonic. 

 T. gallica and africana are remarkable for the quantity of sulphate of soda 

 which their ashes contain. Dec. Dr. Ehrenberg found that the Manna of 

 Mount Sinai is produced by a variety of Tamarix galhca. This substance, 

 being analysed by M. Mitscherlich, was found to contain no crystallisable 

 Mannite, but to consist wholly of pure mucilaginous sugar. Ann. des Sc. 1. c 



Examples. Tamarix, Myricaria. 



fr 



CXLIII. ELATINE/E. The Water-Pepper Tribe. 



Elatineje, Cambessedes in Mem. Mus. 18. 225. (1829.) 



Diagnosis. Polypetalous dicotyledons, with definite hypogynous distinct 

 stamens, concrete carpella, an ovarium of several cells with the placentae in 

 the axis, an imbricated calyx, S3uumetrical flowers, indefinite exalbuminous 

 seeds with a straight embryo, capitate stigmas, a fruit with the valves alter- 

 nate with the septa, and a persistent axis and herbaceous stems. 



Anomalies. 



Essential Character. — Sepals 3-5, distinct, or slightly connate at the hase. Petals hypo- 

 gynous, alternate with the sepals. Stamens. hypogynous, usually twice as numerous as the 

 petals. Ovarium with from 3 to 5 hypogynous cells, an equal number of styles, and capitate 

 stigmas. Fruit capsular, 3-5-celled, with the valves alternate with the septa, which usually 

 adhere to a central axis, but in Merimea to the valves separating from the axis. Seeds nume- 

 rous, with a straight embryo, whose radicle is turned to the hilum, and no albumen. — Annuals, 

 found in marshy places. Stems fistulous, rooting. Leaves opposite, without stipulte. 



Affinities. This little order has been recently established by M. Cambes- 

 sedes, who distinguishes them from Caryophylleas, with which a part of them 

 had been confounded, by their capitate stigmata, by the dehiscence of their 

 fruit, and by their want of albumen. They agree wilh Hypericineae in many 

 respects, even in the presence of receptacles of resinous secretions ; but differ 

 in having a persistent central axis in the fruit, definite stamens, and so forth. 



Geography. Found in marshes in the four quarters of the globe. The 

 Elatines are natives of Europe, Bergias of the Cape of Good Hope and the 

 East Indies, and Merimea of South America. 



Properties. Unknown. 



Examples. Elatine. Bergia. Crypta, Merimea. 



