POTAMOGETON DIVERSIFOLIUM. 



VARIOUS-LEAVED POND WEED. SMALLEST POND WEED. 



Tctrandr'ia Tctragynia, Linn. Xaj aides, Juss. 



GENERIC CHARACTER. 



Calix 4-leaved. Corolla 0. Style O. Seeds 4. Leaves sheathing; those of the stem 

 often attenuated, floral leaves mostly opposite ; flowers spiked, terminal, or 

 axillary; ramuli and spikes having frequently two sheathes at the base. 

 Nutt one-seeded, cochleated ; embryon erect, exalbuminous, curved, invo- 

 luted. — Nutt. 



SPECIFIC CHARACTER. 



Plant small, delicate ; stem filiform, emersed ; floating leaves elliptical, pctiolated, 

 half an inch long, six-nerved ; submersed leaves sessile, filiform, long; spikes 

 numerous, small, depressed, in the axilla of the leaves. — B. Prod. Fl. Ph. 



A singular and delicate little plant. Upper leaves about half an 

 inch long, and not quite a quarter wide, elliptical, somewhat convex 

 on their disk, dark, shining sap-green, six-nerved, (rather six-grooved, 

 the nerves being depressed,) petioles very short Submersed leaves 

 very delicately filiform. Stem filiform. Flowers few, borne on axillary, 



