The Duckweed. 189 



r~ous, and the long, slender, twining stem, with its hastate 

 ps is easily recognised. A larger flowered species, but 

 . , gjfnilar leaves, C. Sepium, is found in the same places, 

 the surface of stagnant waters at this season will often be 

 patches of green, which when examined will be found to 

 ■ st f a collection of small floating leaves, each about an 

 • h Ion", with a cleft in one side, from which proceeds a 

 nute flower, with two stamens and a single style. From the 

 entre of the leaf hangs down into the water a solitary root, 

 with ci kind of sheath at the end. This is Lemna. minor, Duck- 

 mea t and is well worth placing under the microscope. A 

 more rare plant than almost any we have mentioned, is that 

 slender and delicate vine, which may sometimes be found 

 mon(r hedges, with its three-nerved, heart-shaped leaves, and 

 fascicles of small greenish flowers. This is Dioscorea villosa, a 

 species of the same genus which produces the Yam. It is pre- 

 sumed that the collector has already, if he has been at all 

 among the woods and thickets, had his coat torn and his 

 hands scratched by that nuisance, the Bull Brier — called so, 

 we suppose, from its being strong enough to stop the progress 

 of the maddest of the Vaccine family — with its long thorny 

 stems. If he has made its acquaintance in this way, we need 

 only direct his attention to its umbels of green flowers, and 

 remind him that its name is Smilax rotundi folia. As to the 

 Grasses, Cyperaceae, and Juncaceae, hundreds of which are 

 now flowering, we can but hope that the reader will have 

 patience to study them. 



THE DUCKWEED. 



As we have mentioned the Duckweed {Lemna minor) among 

 those plants which flower in June, the following description 

 of its structure may induce the reader to seek for and exam- 

 ine it : — 



In Duckweed there is nothing but a fleshy floating green 

 body, which looks like a green scale, and which is in reality a 



