BOOS, MARSHES, WET PLACES— SUMMER 243 



leaflets that are irregularly cut. The umbels are on long stalks, 

 and have nearly twenty rays, several narrow secondary bracts, 

 and sometimes a few primary ones. The middle flowers of each 

 secondary umbel are perfect and almost sessile, but the outer ones 

 are stalked and staminate. 



3. The Fine-leaved Water Dropwort {(E. Phellandrium) grows 

 from one to four feet high, and has an erect, creeping or floating 

 stem with runners at the base. The upper leaves are bipinnate, 

 with small, cut segments ; 

 and the submerged ones 

 are deeply cut into very 

 narrow, almost hair- like 

 lobes. The umbels are 

 small, on short stalks in 

 the angles of the branches 

 or opposite the leaves. 

 They have about ten 

 rays, narrow secondary 

 bracts, but no primary 

 ones. 



All three of the above 

 species flower from July 

 to September. 



Next follow a few 

 composite flowers (order 

 Compositce), the first of 

 which is the Marsh 

 Thistle {Carduus palus- 

 tris) that varies from two 

 to eight feet in height, 

 and bears dense clusters 

 of purple (occasionally 



white) heads during July and August. Its stem is stiff, hollow, 

 slightly branched, and thickly covered with very prickly wings 

 that are continuous with the margins of leaves above them. The 

 leaves are narrow, wavy, deeply divided into prickly lobes, with 

 scattered hairs on both surfaces ; the lower ones often seven or 

 eight inches long ; and the upper much smaller and narrower. 

 The flower-heads are ovoid, surrounded by an involucre of many 

 closely-overlapping bracts with prickly tips. 



The two Bur Marigolds (Bidens) are more or less common in 



R 2 



The Marsh thistle. 



