White to Green and Brown Flowers 135 



NORTHERN ROCK CRESS 



Braya humilis. Mustard Family 



Stems: erect, branching below. Leaves: spatulate, the lower ob- 

 tuse, sharply dentate, the upper smaller and narrower, acute. Flowers: 

 on ascending pedicels. Fruit: pods terete, glabrous, linear. 



This plant closely resembles the Tansy Mustards. It has 

 white, rarely pinkish flowers, and a basal rosette of coarsely 

 toothed leaves, the upper leaves being narrow and even- 

 margined. 



WATER CRESS 



Radicula Nasturtium-aquaticum. Mustard Family 



Aquatic, glabrous; root fibrous. Stems: stout, hollow, rooting at the 

 decumbent base. Leaves: pinnate, leaflets rounded or elongated, the 

 terminal ones largest. Flowers: petals white; sepals four, early-falling; 

 stamens six; style short, thick. Fruit: pods divaricately spreading, 

 seeds in two rows. Not indigenous. 



Surely it is a libel to call this plant Nasturtium, which 

 signifies " twisted nose," and is given to Water Cress simply 

 because we are supposed to turn up our noses when we eat 

 its acrid leaves. Those who go out to gather flowers will 

 seldom pause to pick this insignificant plant, whose clusters 

 of small white flowers grow close beside, or actually in, the 

 streams and ponds, and whose only claim upon our attention 

 lies in the pleasant pungent flavour of its leaves. This is 

 an introduced plant. 



WHITE BITTER CRESS 

 Cardamine pennsylvanica. Mustard Family 



Stems: glabrous, erect, rather stout. Leaves: pinnately divided, the 

 terminal segment oval and narrowed at the base, all toothed. Flowers: 

 in corymbose racemes. Fruit: pods narrowly linear, erect when ma- 

 ture. 



