34 



UNJERSHRUBS. 



C. UNDERSHRUBS, BOG PLANTS OR ROCKERY PLANTS 



1. Forming cushions or mats: essentially evergreen. 2. 

 Not growing in dense mats. 15. 



Matted Plants. 



2. Leaves simple. 3. 



Leaves digitately compound, of 3 leaflets. 14. 



3. Leaves brown-scurfy, elliptical. Rhododendron. 

 Leaves not scurfy. 4. 



4. Leaves white-hairy beneath, crenate. . Dryas. 

 Leaves not woolly, entire. 5. 



5. Leaves crowded close to the ground. 6. 

 Leaves on more or less elongated stems. /. 



6. Leaves fleshy. Sedum. 

 Leaves not fleshy. Silene. 



7. Leaves widened upwards. Diapensia. 

 Leaves not widened upwards. 8. 



8. Leaves revolute. Empetrum. 

 Leaves not revolute. 9. 



9. Leaves veinless, crowded. 10. 

 Leaves veined. 12. 



10. Leaves needle-shaped : moss-like. Cassiope. 

 Leaves lanceolate or oblong: more open. n. 



11. Leaves oblong. Phyllodoce. 

 Leaves lanceolate. Phlox. 



12. Leaves elliptical or obovate, dotted beneath. Vaccinitim. 

 Leaves rather lanceolate, not dotted. 13. 



13. Stems nearly herbaceous : leaves bristle-tipped. Phlox. 

 Stems woody : leaves not bristle-tipped. Pyxidanthera. 



14. Stipules small. Potentilla. 

 Stipules elongated along the leaf-stalk. Sibbaldia. 



15. Loosely low-bushy : leaves simple. 16. 

 Neither matted nor bushy. 38. 



