HVDRALES.] 



HYDROCHARIDACEiE. 



141 



V 



Order XXXIX. HYDROCHARIDACEiE.— Hydrocharads. 



Hydrocharides, Juss. Gen. 67. (1780.)— Hydrocharideae, DC. Fl. Fr. 3. 265. (181.5) ; R. Brown Prodr. 

 344. (1810) ; Richard in Mem. J/mj?. vol. 1. 365. (1815); Agardh Aph. 127. (1822), Endl. gen.Wx. 

 Meisi er, p. 365.— Vallisneriaoeae and Stratiotese, Link Handb. 1. 281. (1829). — Anacharideae, 

 Endl. gen. p. 161. 



Diagnosis. — Hydral Endogens with epigynous stamens and an adherent ovary. 



Floating or water-plants. Leaves with parallel veins, sometimes spiny. Flowers 

 enclosed in a spathe, (^ ^ (or occasionally p). Sepals 3, herbaceous. Petals 3, peta- 

 loid, occasionally absent. Stamens definite or indefinite. Ovary adherent, composed of 

 several carpels, and 1- 6- 8- 9-celled ; stigmas 3-6 ; o\-ules indefinite, 

 anatropal, often parietal. Fruit dry or succulent, indehiscent, ^vith 1 

 or more cells. Seeds without albumen ; embryo undi\'ided, orthotro- 

 pal, with a plumule more or less lateral and generally manifest. 



Such appear to be the essential characteristics of tliis singular 

 group of plants, whose inflorescence lives and passes through all the 

 stages of its existence imder water, except just at the time when fer- 

 tilization is necessary, when the flowers rise above the surface for a 

 few hours. Dan\'in has celebrated the so-called phenomena connected 

 with this function in Vahsneria spu'ahs, (see \as Loves of the Plants) ; 

 but they are greatly in need of more accurate investigation. Mr. Que- 

 kett, in an elaborate memoir on this plant, {London Phys. Journ. 1. 

 65,) considers that a part at least of the statements are fabulous. 



It is not easy to detemiine what is the immediate affinity of Hydro- 

 charads. Theu' exalbuminous seeds and diclinous flowers distinguish 

 them from BromeUacese, to which theu* adherent ovai'y, and the 

 habit of the Water-soldier (Stratiotes) seems to approach them ; 

 from Naiads, theu' indefinite seeds and adherent ovary equally 

 divide them. By then' tripetaloideous flowers, with an inferior 

 ovary, they are separated from Alismads, with wliich some agree 

 in habit and want of albumen, but from which they differ in their car- 

 pellary leaves being definite, not indefinite. Commelynacese are at 

 once recognised by their superior trilocular ovary. Agardh refers 

 here Trapa ! Linnaeus placed Hydrocharads along with Palms ! 

 in his natui'al aii'angement. Hydrocharis Morsus Ranae has been 

 compared, and not unaptly, to a pigmy Nj-mphsea, Perhaps, taking 

 into account their diclinous flowers, the universal presence of a 

 spathe and theh' aquatic nature, they may be regarded as approaching 

 to Arads through Lemnads, 



Natives of fresh water in Europe, North America, and the East 

 Indies, One species is fomid hi Egypt (Da- 

 masonium indicum), and two V^allisnerias m 

 New Holland. A few occur m estuaries of 

 the sea. 



Nothing is knoA\Ti of their uses, unless that 

 the fruit of Enhalus is eatable, and its fibres 

 capable of being woven, according to Agardh 

 {Aph. 128). The Jangi of Hhidostan, called 

 Valhsneria alternifolia by Roxburgh, Hydrilla 

 by Hamilton, is one of the plants used in Incha 

 for suppl}Tng water mechanically to sugar in 

 the process of refining it, " as clay is used in 

 the West Indies to permit the slow percola- 

 tion of water." — Royle. The herbage of Hy- 

 drocharis Morsus Ranae is mucilaghious and 

 slightly astringent. Ottiha and Boottia are 

 eaten in India as potherbs. 



Fig. XCIII. 



Fig. XCIII.— Stratiotes aloides. 1. a flower and spathe 

 spathe; 4. a section of the fruit ; 5. an embryo. 



2. a flower split open ; 3. a fruit in its 



