253 



CCXXIX. ALISMACEiE. The Water-Plantain Tribe. 



Alismace.f., R. Brown Prodr. 342. mpar^(1810); Rich, in Mim. Mus. 1. 365. (1815) ; 

 Juss.Dict. Sc. Nat. 1. 217- (1822); Lindl. Synops. 253. (1829). — Ausmoide/I':, 

 Dec. Fl.Fr. 3. 188. (1815.) 



Diagnosis. Tripetaloideous monocotyledons, with numerous, distinct, 

 superior carpella. 

 Anomalies. 



Essential Characteh. — Sepals 3, herbaceous. Petals 3, Tpetaloid. StamcTis de- 

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

 or 2 attached to the suture at a distance from each other. Styles and stigmas the same 

 numtier 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 Ranunculacese are 

 to Polypetalous Dicotyledons, and is in like manner recognised by its inde- 

 finite distinct carpella and hypogynous stamens; from Butomege it is known 

 by the indefinite ovula of that order being scattered over the face of the cells. 

 Juncaginea^ sometimes referred to Alismacese, appear nearer Aroideae, and 

 are distinguished by their depauperated floral envelopes, concrete carpella, 

 and straight embryo having a lateral slit for the emission of the plumula. 

 The plants belonging to Alismaceae, Hydrocharideae, Fluviales, Juncaginese, 

 and Butomea?, have all a disproportionately large radicle, whence the em- 

 bryos of such were called by the lute M. Richard, macropodal. 



Geography. Chiefly natives of the northern parts of the world. Seve- 

 ral Sagittarias and Actinocarpus inhabit the tropics, the former of both 

 hemispheres. 



Properties. All aciuatic 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. Agdh. 



Examples. Sagittaria, Echinodorus, Alisma, Actinocarpus. 



CCXXX. BUTOME.E. The Flowering Rush Tribe. 



BuTOMEiE, Richard in Mim. Mus. 1. 364. (1815) ; Lindley's Synopsis, 271. (1829) ; Dec. 

 and Duby, 437. (1828) a § o/ Alismaceae. 



Diagnosis. Tripetaloideous monocotyledons, with the placenta3 cover- 

 ing 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. 

 Stamens definite or indefinite, hypogynous. Ovaries superior, 3, 6, or more, either dis- 

 tinct 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 cellu- 

 lar, often yielding a milky juice, with parallel veins. Flowers in umbels, conspicuous, 

 purple, or yellow. 



Affinities. Although an undoubted tripetaloideous order, yet Buto- 

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



