\ Potamoffeton.J cr. naiadace^. a^ 



h 



% : 



\ 



i 

 ■i 



selr. 





c 



m 



\ 





i 



epas 



i 



^ 



inorf. 



essil' 





it' 



ffif 



479 



issues from a sheathint? bradea (or spathaf). Perianth single 

 of 4 clawed scales. Stamens 4. Anthers sessile, opposite the 

 scales of the perianth. PM/^ 4, which become 4 sessile 

 achenes. Styles and stigmas undivided. —JSTamed from Trora/zof 

 a mer, and yuvi^v, a neighbour. All the species grow in the 

 water, and often present as beautiful an appearance in clear 

 streams and ponds, as the Fuci do in the ocean. They protect 

 the spawn of fish, and harbour Innumerable aquatic insects 

 then- roots and seeds affording food to water-birds. Chamisso' 

 and Schlechtendal have well illustrated this genus. (See 

 Linnma, ii. p. 159.) ° ' \ 



* 



Leaves all opposite and submerged ; stipules none. 



1. P. densusL. (opposite-leaved P.); leaves crowded all 

 opposite pellucid amplexicaul ovate-acuminate or lanceolate 



spikes, shortly stalked about 4-flowered finally reflexed/^"'"""' 



E.B. 



Ditches, frequent. %. 6, 7. - Peduncles short, Head of flowers 

 ^i smaU rounded. Leaves keeled below, middle nerve or rib of many 



longitudinal cells, with 2 and sometimes 3 lateral parallel veins on 

 each side, the inner one the strongest. 



** Leaves alternate, all submerged, with adnate stipules. 



2. F. pectindtus L. {Fennel-leaved P.) ; leaves distichous se- 

 taceous or Imeal 1-3-nerved sheathing by means of their 

 adnate stipules, upper ones 1-3-nerved, spike interrupted, 

 achenes large 3-nbbed at the back, the two lateral ribs some- 



SpL •.?'':r "t" ^^""T"^? setaceous 1-nerved canaliculate, 

 achenes with the lateral keels conspicuous. E. B. t. 323 

 r. mannus L. ~f3. leaves broader, upper ones 3-nerved, lower 

 5-nerved, achenes with the lateral keels inconspicuous. P pec- 

 tuiatus var. vulgaris Ch. and Schl. P. flabellatus Bab. 



Hull Y ^"f^ I^"™l^am, Norfolk; Coventry, Bath, Gravesend, 



' I ider^/ " ^/^- '' ''^""^ Chamisso and Schlechtendal con- 



irtcr the common form of the species j for although in the spe- 



Rivers, lakes, ponds, and salt-marshes. Near Ayr, Scotland. 

 ^^ Denver and Burnham, Norfolk; Coventrv, Bath, GravesP 



tha 

 sidi 



Sn Mr T^^ •*^' ''"'' ^^°"^> ^^^« ^" ^d^^''°-l "-^« "-- each 



rflffeCce Ts in t"^'""!-''^! °^^^' ^' >^^^^«^«^' that the principal 



difficult to ,k. i,'"'r ^'^'''' ^"* *''^t ^^h^" i" f^»it it is very 



'nicult to distinguish it from P. pectinatus. ^ 



setL^;fl'^t'"''%^f'\f?^'"?^'"'^^«"^^ ^•)5 ^^^^^^^ distichous 

 sp ke into - f ^l^eathing by means of their adnate stipules, 



the ba r ';^r''^' ^^^rf/^,"^ but not ribbed on 



*•' the Vinol- "p^"' "^'^c^cfl V»'"aii; roundec 



y ^ue back. Cham, and Schlccht. I.e. p. 167. 



