64 ROSACEAE 



lous yellow flowers in stalked corymbose clusters; and several 



akenes in each persistent calyx. 



Leaflets cuneate, crenately toothed at end. S. procumbens. 



POTENTILLA. Cinquefoil. 



Usually perennial herbs; a few deciduous shrubs with 

 brownish wood with minute diffused ducts, somewhat more 

 sparse in summer, and fine medullary rays; somewhat angular 

 brown continuous pith; alternate minute round raised leaf- 

 scars with a single bundle-trace, flanked by persistent stipules; 

 small ovoid buds; compound leaves with several rather small 

 leaflets; perfect open usually yellow polypetalous perigynous 

 flowers with bractlets on the calyx; and numerous small 

 akenes. 



Leaves pinnate: leaflets linear, entire. P. fruticosa. 



Leaves palmate: leaflets 3, notched at end. P. tridentata. 



DRYAS. 



Small matted trailing woody evergreens with rather small 

 alternate slender-stalked simple leaves, white-woolly beneath; 

 rather large perfect open polypetalous perigynous flowers sol- 

 itary at ends of long erect stalks; and large clusters of long 

 feathery-tailed akenes. 



1. Leaves entire. D. integrifolia. 

 Leaves crenately serrate. 2. 



2. Flowers white: sepals narrow. D. octopetala. 

 Flowers yellow: sepals ovate. D. Drummondii. 



RUBUS. Bramble. 



Tardily deciduous mostly prickly shrubs with moderately 

 slender more or less angular twigs; continuous pith of corre- 

 sponding shape; alternate raised torn petiole-bases rather than 

 distinct leaf -scars; no stipule-scars; ovoid sometimes super- 

 posed buds with several exposed scales; simple or mostly com- 

 pound often toothed petioled leaves; conspicuous perfect usual- 

 ly clustered polypetalous perigynous flowers; and small drupe- 

 like fruits in a cluster which breaks away from each persistent 

 calyx with the end of the receptacle (blackberries), or separ- 



