6o Haloragaceae — Lythracea^. 



ORDER 25. — Haloragaceae. 



Calyx superior limb minute. Petals minute or wanting. Stamens 4 or 8 

 or only i. Flowers sometimes monoecious. Ovary of 2 to 4 carpels. Styles 

 separate. Mostly aquatic plants with insignificant flowers. 



Leaves entire, 270 



Leaves cut, ....... Myriophyllum IT. 



270 Leaves whorled . Hippuris I. 



270 Lower leaves opposite, .... Callitriche III. 



HIPPU'RIS VULGA'RIS (86). Mare's Tail. 6—7. Perianth single 



(577) superior forming a mere rim to the ovary, stamen I, style I, leaves 

 linear 6 — 8 in a whorl, stem erect jointed. Ditches. Fig. p. 65. 



II. —MYRIOPHYLL UM. 



Monoecious. Staminate Jlowers^ calyx 4-lobed, petals 2 or 4, stamens 8. 

 Fistillaie JiowerSy calyx with 4 minute lobes, petals minute, ovary 

 4-celled, styles 4, leaves whorled finely pectinate. 



Bracts longer than the flowers, ..... M. verticillatum. 



Bracts not longer than the flowers, M . spicatum. 



MYRIOPHYL'LUM SPICATUM (65). 6—8. Bracts small, spike 

 (579) protruding from the water. Ponds and ditches. 



Myriophyl'lum verticilla'tum (49). 7—8. Bracts pinnate like the leaves 



(578) longer than the flowers, spike submerged. [W. C. CI. 



III.— CALLITRICHE. 



CALLI'TRICHE VER'NA (93). Water Star-wort. 4—9. Leaves 

 (581- opposite, flowers monoecious minute axillary. Staminate flowers ^ 

 584) stamen I. Pistillate flowers, ovary sessile, styles 2, upper leaves in a 

 rosette. Ditches. 



ORDER 26. — Lythraceae. 



Calyx gamosepalous inferior ribbed, teeth 8 — 12. Corolla polypetalous, 

 perigynous. Petals 4 — 6, sometimes o. Stamens usually 6 or 12, perigynous. 

 Pistil syncarpous of 2 carpels. Style i. Stigma i. Leaves entire without 

 stipules. 



Calyx cylindrical, style long, Lythrum I. 



Calyx campanulate, style short, Peplis II. 



