159 



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

 Mount Sinai is produced by a variety of Tamarix gallica. 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. 



CXLIII. ELATINEiE. The Water-Pepper Tribe. 



Elatine.i:, Cambesstdes in Mem. Mus. 18. 225. (1829). 



Diagnosis. Polypetalous dicotyledons, with definite hypogynous dis- 

 tinct stamens, concrete carpella, an ovarium of several cells with the pla- 

 centse in the axis, an imbricated calyx, symmetrical flowers, indefinite exal- 

 buminous seeds with a straight embryo, capitate stigmas, a fruit with the 

 valves alternate with the septa, and a persistent axis and herbaceous stems. 



Anomalies. 



Essentia!, Character Sepals 3-5, distinct, or slightly connate at the base. 



Petals hypogynous, 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 numerous, 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 stipula. 



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

 bessedes, who distinguishes them from Caryophyllese, 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 with Hypericinese 

 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, 



CXLIV. PORTULACE.E. The Purslane Tribe. 



PoRTULACE^., Juss. Gen. 313. (1789) in part; A. St. Hil. Mem. Plac. Cent. 42. (1815) ; 

 Dec. Prodr. 3. 351. (1828); Lindl. Synops. 62. (1829); Dec. Mem. de la Soc. 

 d'llist. Nat. de Paris, {Any. 1827). 



Diagnosis. Polypetalous dicotyledons, with unsymmetrical perigynous 

 stamens, concrete carpella, a 1 -celled ovarium, herbaceous stems, stamens 

 opposite the petals or twice as many, 2 sepals, and naked seeds with the 

 embryo curved round the albumen. 



Anomalies. Sepals 5 in Trianthema and Cypselea. Petals sometimes 

 wanting. 



Essential Character — Sepals 2, seldom 3 or 5, cohering by the base. Petals 

 generally 5, occasionally 3, 4, or 6, either distinct or cohering in a short tube, sometinfies 



