Ilippuridese. Caliitrichinese. Ceratophyllacese. Lythraceee. 
173 
36. Hippuridese. 
190. Hippuris. !Vlare’s-taiS. I, 2. 
1. Ls linear, in whorls of 8 —12. FIs in the l.-axils, not 
very visible. — b. rhwtica Zscholcke. Stem only 15— 20 cm ?; 
Is narrower (*/2 mm broad).—Stagnant water or sluggish 
streams; distrib.; b. Graub. 5 . . vulgaris L. 834. 
37. Callitrichinese. 
191. Callitriche. Callitriche. XXI, 23.' I, 2. 
1. Ls dark green, always of the same form, linear, rather 
enlarged at the base, the pairs gen. close together, but the 
upper ones never rosetted.— Stagnant water ; its presence 
in Switzerland is not yet proved with certainly. 7 
*autumnaiis L. 835. 
— Ls light-green, entirely linear, with equal breadth, or more 
often enlarged above and narrower towards the base, the 
upper ones in an ordinary rosette, spathulate-obovate. 
Type of C r>erna Tj. . . . . . . . *? 
2. Fr. broadly keeled (slightly winged). Styles of moderate 
length, erect or spreading, persist. Ls all obovate or 
(b. platycarpa Kiitz.) the lower ones linear.—As the 
last; probably distrib. 5 . . stagnalis Scop 836. 
— Fr. surrounded by a very narrow, sharp keel. Styles of 
moderate length, erect, persist, almost till maturity.— 
As the last. 5 .... vernalis Kiitz. 837. 
— Fr.-surrounded by a narrow, sharp keel. Styles very 
long, spreading, then reflexed, falling early. —As the last. 5 
hamulata Kiitz. 838. 
33. Ceratophyllaceae. 
192. Ceratophyllum. Ceratophyil. XXI, 19. 
1 Ls rather stiff, brittle, dark green, with 2—4 linear lobes 
which are strongly toothed-spinous. Fr. with a terminal 
spine which is as long as, or longer than, itself.—Stagnant 
water in the Swiss plains. 7 . . demersum L. 839. 
— Ls softer, light green, with 5 — 8 linear-filiform lobes, 
armed with distant, spinous teeth. Fr. terminated by a 
spine much shorter than the fr. itself. —As the last, but 
much rarer; T. AY. V. J. B. Z. 7 . submersum L. 840. 
39. Lythracese. 
193. Lythrum. lythrum. XI, 5. VI, 5. 
1. FIs in whorls disposed in a long spike. Stas twice as 
many as the pets.—Var.: fls trimorphous, with styles of 
