(230) 



pie, rarely a divisor. Carpidia united into a 

 single ovary. 



Family 1. HALORRHAGIDE^, 



Calyx tube adnate to the ovary; limb 4-parted. 

 Petals, if present, alternate with calyx lobes. 

 Stamens not more than twice as many as petals; 

 if of equal number opposite to them. Pla- 

 centse central, 1-ovulate. Styles as many 

 as cells. 



1, Hippuris L- MARE'S TAIL. 



Flowers $ , or sometimes polygamous, mo- 

 nandrous; filament subulate. Ovary 1-celled, 

 1-ovulate, style filiform. Fruit a caryopsis. 11 . 

 Aquatic. Leaves verticillate; flowers minute, 

 solitary in the axils. 



1. H.VULGABIS L. Marine Hospital (at pres- 

 ent extinct). Summer. 



2, Myriophyllum L. WATKR MILFOIL. 



Monoecious. $ : petals caducous; stamens 8. 

 ? : calyx limb and petals minute; stigma vil- 

 lous; ovary 4-celled, 4-ovulate. 



1. M. SPICATUM L. Marine Hospital. 

 Camp Taylor. Summer. 



Family 2, ONAGRACE^, 



Calyx tube adnate to the ovary. Petals al- 

 ternate with them, not valvate in aestivation. 

 Stamens inserted with petals, as many or a 



