RIVER-SIDE FLOWERS. 391 



Fig. in " E. B.," 537 rears its umbelliferous head in slow- 

 running streams in July, when the so-called weeds are 

 allowed to grow. (The NARROW-LEAVED WATER-PARSNEP 

 (Stum angustifolium), is also common enough, but does 

 not grow so high.) The stem is sometimes as high as six 

 feet, often from four to five ; it is deeply furrowed and 

 leafy ; the leaflets are spear-shaped and serrated ; those 

 of the leaves which grow under water are often pinnatifid 

 (feather-cut). Hooker says the Sium is derived from the 

 Celtic word, siw, water. Flowers July and August. 



The COMMON ARROW-HEAD (Sagittaria sagittifoUa) Fig. 

 in " E. B.," 1436 is another of the beautiful aquatics found 

 on the margin of our rivers in the months of July and 

 August. The leaves come from the root on long, trian- 

 gular, very cellular foot-stalks. Those below the surface 

 are long and strap-shaped. Those above the water are 

 large and arrow-shaped, very entire, with parallel ribs and 

 reticulated veins. The flowers, three in each whorl, are 

 white, with a purplish tinge at the claw. 



The GREAT WATER - PLANTAIN, GREAT THRUMWORT 

 (Alisma plantago)\g. in " E. B.," 1438 from the Celtic 

 word, alt's, water, is another very common plant. The 

 stem is from two to three feet high. The leaves all start 

 from the root on long stalks. Flowers of a pale rose 

 colour. This plant was supposed to be a cure for hydro- 

 phobia, and was the chief ingredient in all the drinks 

 given for that purpose ; it was also supplied as poultices 

 to the bite. Flowers July and August. 



There are two other species : the FLOATING WATER- 

 PLANTAIN (A. natans) Fig. in " E. B.," 1441 found on the 

 lakes in North Wales and Cumberland ; and the LESSER 

 WATER-PLANTAIN (A. ranunculoides), found in ditches and 

 wet places. 



In large open waters or in ponds may be noticed a 

 longish, thread-like, much branched, floating weed, with 

 pretty-looking white star-like flowers, one (the fertile) 

 with a long anther. This is the COMMON HORN POND- WEED 

 (Zannichellia palustris} Fig. in " E. B.," 1425-1426; Nat. 

 Ord. Fluviales) named, according to Hooker, in honour of 



