IIYDROCnARIUACK^E 81 



3 outer oblong, hooded, subherbaceous, the 3 mner scarcely larger, 

 oblong, subpetaloid : stamens 9, more rarely 3 ; filaments short and 

 monadelphous, or absent. Female flowers sohtarj', sessile, from a 

 1-Ieaved sessile axillary spathe, which is 2-toothed at the apex ; tube 

 of the perianth coloured, adhering to the ovary, and extending to a 

 great length beyond it ; limb 6-partite, the 3 outer segments oblong, 

 hooded, herbaceous, the 3 inner scarcely larger, oblong, reflexed, 

 petaloid : stamens 3 or 6, usually reduced to sterile filaments, rarely 

 with subsessile anthers : ovary adhering to the base of the tube of 

 the perianth, 1 -celled, with 3 parietal placentae, each of which bears a 

 few o\'ules ; style single, veiy long, capillary, adnate to the tube of 

 the perianth ; stigmas o-notched or bifid. Fruit " oblong, coriaceous, 

 few-seeded." (Gray.) 



Stems submerged, brittle, mth verticillate ovate or oblong or strap- 

 shaped leaves and minute flowers, the female with the lilac perianth 

 limb restmg on the surface of the water. The male flowers are said 

 to break off and float on the water ; but they are unknown in this 

 country. 



■fCorue derived from iXiJtc, marshy. 



SPECIES I.— E LODIA CANADENSIS. Michaux. 

 Plate MCCCCXLVL 



Anactaris Alsinastmm, Bah. in Ann. Nat. Hist. Ser. II. p. 83. Engl. Bot. Suppl. No. 



2993. Man. Brit. Bot. ed. vi. p. 823. 

 A. Alsinastrum, A. Nattallii, and A. Canadensis, Planch, in Ann. Nat. Hist. Ser. 11. 



Vol. I. p. 86. 

 Udora Canadensis, Nntt. Gen. N. Americ. PI. Vol. 11. p. 242. 

 Apalanthe Schweinetzii, Planch. Ann. Nat. Hist. Ser. TL. Vol. I. p. 87. 



Leaves in verticils of 3 (more rarely 4) or the lower ones opposite, 

 oval-oblong or ovate-oblong or lanceolate-oblong or strapshapcd, very 

 finely and obscurely serrulate. Stigmas reflexed, often 3-lobed. 



A North American plant, noticed in 1842, in a pond at Dunse 

 Castle, Berwickshire, by the late Dr. G. Johnston; irom thence it 

 spread to the River Whitadder, and probably from the same place 

 was carried to the pond in the Botanic Garden at Edinburgh, whence 

 it has been taken to other places in the neighbourhood. Shortly 

 before the year 1847, it appears to have been introduced vnth. timber 

 from North America to the canal basin at Foxton, near Market Har- 

 borough, Leicestershire ; and from this second centre it has now 

 spread over the greater part of England. Li Ireland, at the date of 

 the pubfication of the " Cybele Hibernica," 186G, it was still ratlier 



VOL. IX. - M 



