CLASS IV. ORDER I. 65 



A slender shrub six or seven feet high. Leaves smooth, oval, 

 entire, or slightly toothed, often mucronated. Flowers small, 

 green, on long slender peduncles. Corolla of four spreading, 

 acute segments. Stamens four, as long as the corolla. Germ 

 round, pointed in the barren flowers; longer and bearing a four 

 lobed stigma in the perfect ones ; the shrub being strictly poly- 

 gamous. Berries deep red. — Swamps, Cambridge. — May. 



7.3. SAGINA, 

 Sagina procumbens. L. Pearl wort. 



Perennial ; stems procumbent, smooth ; petals very- 

 short. 



A small spreading plant, the stem branched and throwing out 

 roots. Leaves opposite, linear subulate, connate at base. 

 Peduncles axillary, solitary, longer than the leaves. Petals half 

 as long as the calyx, sometimes wanting. — la wet places mostly. 

 —July. 



74. POTAMOGETON. 



PoTAMOGETON NATANS. L. Floating Pond weed. 



Upper leaves oblong-ovate, rounded at the base, 

 petioled, floating. Stti. 



A very common species of pond weed, growing near the mud- 

 dy banks of deep waters. Leaves oblong, sometimes a little 

 hearted at base, two inches long, floating on the surface, on foot- 

 stalks accommodated to the depth of the water. In June the 

 spikes of dull flowers emerge on solitary round footstalks, sur- 

 rounded at base by lanceolate bractes or stipulse. 



PoTAMOGETON FLDiTANS. L. Long haved Pond weed. 

 Leaves petioled, lower ones linear, very long, up- 

 per ones lanceolate, nerved, coriaceous. 



Leaves narrower than the preceding, the immersed ones very 

 long and linear. — Ponds. — June. 



PoTAMOGETON PERFOLiATUM. L. Perfoliate Pond weed. 



Leaves cordate-ovate, clasping, all immersed ; 



spikes terminal ; flowers alternate. 



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