62 CLASS TETRAKURIA. 



of flowers, only a single scarlet berry is produced, 

 but containing four seeds. 



The Cornus (Cornel or Dogwood), with which 

 the United States abound in species, are small trees 

 or shrubs bearing flat clusters or cymes of flowers 

 resembling those of the Elder, and commonly white. 

 In the Dog-wood ( Cornus florida), these small flow- 

 ers are aggregated into flat heads, like compound 

 flowers, surrounded by an involucrum of four leaves, 

 which gradually grow out, and become of a white 

 color, adding, from the latter end of May to June, 

 one of the greatest and most characteristic vegetable 

 features to our vernal landscape. Examined a little 

 more closely, the minute flowers of the head consist 

 each of a 4-toothed calyx ; and 4 narrow, spread- 

 ing, pointed petals ; to these succeeds a red drupe, 

 or succulent stone-fruit, inclosing a nut of 2 cells. 

 Almost exactly similar to the arborescent Dog-wood, 

 is the humble Canadian species (Cornus canadensis), 

 which runs at the root, and sends up at near intervals, 

 small herbaceous stems four or five inches high, ter- 

 minating in a tuft of ovate leaves, and a single cluster 

 or head of flowers. This is one of our northern 

 species found amidst bushes, in shady woods, and 

 scarcely differs horn a similar species, the Cornus 

 suecica, of northern Europe. 



One of our earliest flowering plants of tins class, 

 belonging to the family of the Arum, is the Skunk- 

 cabbage (Symplocarpus fuztidus), a foetid plant, which 

 you will often find in flower on the margins of swamps, 

 in the months of February and March, if sufficiently 

 uncovered by the snow. These flowers, in round 

 naked heads, are defended by a kind of cowl or egg- 

 shaped spathe of the most fantastic and marbled color, 

 in which brown and green predominate. The flow- 

 ers of the head, each consist pretty obviously of a 



