Alismales.] 



ALISMACE^. 



209 



Order LXV. ALISMACEtE.— Alismads. 



Alismacese, R. Brown Prodr. 342. in part (1810) ; Rich in Mdm. Mus. 1. 365. (1815) ; Just. Diet. Sc. 

 JN'aM.217. (1822) ; Endl.Gen.xUx. ; Mcisner,Gen. p.36i. KunthEnum.3.U7.—AUBmoidex, DC. 

 Fl. Fr. 3. 188. (1805). 



Diagnosis. — Alismal Endogens with 3-petaloideoiis flowers, few-seeded simple andaxile or 

 based placentae, and a solid embryo. 



Floating or swamp plants, very rarely annual, usually having a creeping fleshy peren- 

 nial rliizorae. Flowers in umbels, racemes or panicles, , very rarely truly $ ^ . 

 Leaves either narrow and strap-shaped, or expanded 

 into a broad blade, always however with the veins 

 parallel. Sepals 3, herbaceous. Petals 3, petaloid. 

 Stamens definite or indefinite ; anthers turned 

 mwards. Ovaries superior, several, 1 -celled ; oAoiles 

 erect or ascending, sohtary, or 2 attached to the 

 suture at a distance from each other, anatropal or 

 campylotropal. Styles and stigmas the same number 

 as the ovaries. Fruit diy, 1- or 2-seeded. Seeds 

 without albumen, hooked ; embryo shaped 

 like a horse-shoe, undivided, with the same 

 dii'ection as the seed. 



This Order is to Endogens what Crow- 

 foots are to Pol}-petalous Exogens, and is 

 in like manner recognised by its disimited 

 cai*pels and hypogynous stamens. Such 

 plants as Ranimculus parnassifolius are 

 hardly distinguishable from Alismads by 

 external characters. Arrow-grasses are 

 known by their imperfect floral envelopes, 

 and straight embryo liaAang a lateral slit for the emission of the plumule. The 

 plants belonging to Alismads, Hydrocliarads, Naiads, Arrow-grasses, and Buto- 

 mads, have all a disproportionately large radicle, whence then* embryos were called 

 by the late L. C. Richard, macropodal. The truly diclinous flowers of Sagittaria 

 constitute a great and unusual exception to the otherwise hermaphrodite structure of 

 this Order. 



Chiefly natives of the northern parts of the world. Several Sagittarias and Damas- 

 oniums inhabit the tropics, the former those of both hemispheres. 



Many have a fleshy rhizome, wliich is eatable ; such are Alisma and Sagittaria : a 

 species of the latter, S. sinensis, is cultivated for food in China ; its herbage is acrid. 

 Alisma Plantago and Sagittaria sagittifolia are among the plants foolishly recommended 

 in hydrophobia ; the rhizome of the foi-mer, deprived of acridity by drying, is eaten by 

 the Kahnucks. Various Brazilian Sagittarias are very astringent ; and their expressed 

 juice is even employed in the preparation of ink. — Martins, mat. m. br. 47. 



GENERA. 



Alisma, Jiiss. 



Echinodorus, Rich. 

 Sagittaria, Linn. 



§ Lophiocarpus , Kth. 

 Damasonium, Jiiss. 



Actinocarpus, R. Br. 



Numbers. Gen. 3. Sp. 50. 



Fig. CXLI. 



CommelynacecB. 



Position. . — Alismace^. — Butomacece. 



RanunculaceoB. 



Fig. CXLI.— 1. Flower of Alisma ranunculoides seen in front ; 2. the same from the rear ; 3. a sec- 

 tion of the ovary ; 4. a section of a seed. 



P 



