CHAPTER XIX. 



CLASSIFICATION OF DICOTYLEDONS (Continued}. 

 DIVISION II. Sympetalce. 



THE Sympetalce or Gamopetalce are at once distinguished 

 from the Choripetalce by having the petals more or less united, 

 so that the corolla is to some extent tubular. In the last order 

 of the Choripetalce we found a few examples (Mimosacecv) 

 where the same thing is true, and these form a transition from 

 the Choripetalce to the Sympetalce. 



There are two great divisions, Isocarpce and Anisocarpce. In 

 the first the carpels are of the same number as the petals and 

 sepals ; in the second fewer. In both cases the carpels are 

 completely united, forming a single, compound pistil. In the 

 Isocarpce there are usually twice as many stamens as petals, 

 occasionally the same number. 



There are three orders of the Isocarpcej viz., Bicornes, Pri- 

 mulince, and Diospyrince. The first is a large order with six 

 families, including many very beautiful plants, and a few of 

 some economic value. Of the six families, all but one (Epa- 

 cridece) are represented in the United States. Of these the 

 Pyrolacece includes the pretty little pyrolas and prince's-pine 

 ( Chimaphila) (Fig. 116, J) ; the Monotropece has as its common- 

 est examples, the curious Indian-pipe (Monotropa uniflora), 

 and pine-sap (M. hypopitys) (Fig. 116, L). These grow on 

 decaying vegetable matter, and are quite devoid of chlorophyll, 

 the former species being pure white throughout (hence a popu- 

 lar name, "ghost flower") ; the latter is yellowish. The mag- 

 nificent rhododendrons and azaleas (Fig. 116, F), and the 

 mountain laurel (Kalmia) (Fig. 116, /), belong to the Rhodo- 

 210 



