251 



CCXXTX. ALISMACE^E The Water-Plantain Tribe. 



Alismaceje, R. Brown Prodr. 342. in part (1810) ; Nick, in Mem. Mus. 1. 365. (1815) ; Juss. 

 Diet. Sc. Nat. 1. 217. (1822) ; Limit. Synops. 253. (1829).-Alismoide.e. Dec. Ft. Fr. 3. 188. 

 (1815.) 



Diagnosis. Tripetaloideous monocotyledons, with numerous, distinct, su- 

 perior carpella. 

 Anomalies. 



Essential Character.— Sepals 3, herbaceous. Petals 3, petaloid. Stamens definite or 

 indefinite. Ovaries superior, several, 1-celled ; ovules erect or ascending, solitary, or 2 at- 

 tached to the suture at a distance from each other. Styles and stigmas the same number as 

 the ovaries. Fruit dry, not opening - , 1-or 2-seeded. Seeds without albumen ; embryo shaped 

 like a horse-shoe, undivided, with the same direction as the seed. — Floating plants. Leaves 

 with parallel veins. 



Affinities. This order is to Monocotyledons what Ranunculaceae are to 

 Polypetalous Dicotyledons, and is in like manner recognised by its indefinite 

 distinct carpella and hypogynous stamens ; from Butomese it is known by the 

 indefinite ovula of that 0|der being scattered over the face of the cells. Junca- 

 gineae, sometimes referred to Alismacea?, appear nearer Aroideee, and are distin- 

 guished by their depauperated floral envelopes, concrete carpella, and straight 

 embryo having a lateral slit for the emission of the plumula. The plants be- 

 longing to Alismaceae, Hydrocharidere, Fluviales, Juncaginese, and Butomeae, 

 have all a disproportionately large radicle, whence the embryos of such were 

 called by the late M. Richard, macropodal. 



Geography. Chiefly natives of the northern parts of the world. Several 

 Sagittarias and Actinocarpus inhabit the tropics, the former of both hemi- 

 spheres. 



Properties. All aquatic plants with a lax tissue, and many with a fleshy 

 rhizoma, which is eatable ; such are Alisma and Sagittaria : a species of the 

 latter is cultivated for food in China. The herbage is acrid. Alisma Plantago 

 is one of the plants recommended in hydrophobia. JLgdh. 



Examples. Sagittaria, Echinodorus, Alisma, Actinocarpus. 



CCXXX. BUTOMEAE. The Flowering Rush Tribe. 



Butome*, Richard in Mem. Mus. 1. 364. (1815); Lindley's Synopsis, 271. (1829) ; Dec. and 

 Duby, 437. (1828) a§ ofAlismacea?. 



Diagnosis. Tripetaloideous monocotyledons, with the placenta? covering 

 the whole lining of the superior carpella. 



Anomalies. In Butomus the calyx is more coloured than usual. 



Essential Character. — Sepals 3, usually herbaceous. Petals 3, coloured, petaloid. Sta- 

 mens definite or indefinite, hypogynous. Ovaries superior, 3, 6, or more, either distinct or 

 united into a single mass ; stigmas the same number as the ovaries, simple. Follicles many- 

 seeded, either distinct and rostrate, or united in a single mass. Seeds minute, very numerous, 

 attached to the whole of the inner surface of the fruit ; albumen none; embryo with the same 

 direction as the seed. Aquatic plants. Leaves very cellular, often yielding a milky juice, 

 with parallel veins. Flowers in umbels, conspicuous, purple, or yellow. 



Affinities. Although an undoubted tripetaloideous order, yet Butomese 

 stand between it and the hexapetaloideous ones, on account of the coloured 



