84 M.OWERS OF LAKES, RIVERS, ETC. 



Essential Si'ecific Ciiakacteks: — 



25. Radiciila amphibia. Druce. — Stem erect, tall, leaves [jinnalifid, 

 entire or dentate, flowers yellow, petals twice as long as calyx, pod 

 straight, ovoid, shorter than pedicels. 



Great Chickweed (.Stcllaria aciuatica, .Scop.) 



Remains of this plant have been found in the Preglacial beds in 

 Norfolk and Interglacial beds in Sussex, testifying to its antiquity. It 

 is to-day fountl in the Temperate Northern Zone in Europe, North 

 Africa, Siberia, Western Asia. In the Peninsula province- it is absent 

 from West Cornwall, and North Hants and E. Su.sse.\ in the Channel 

 province. In .S. Wales it is absent from Glamorgan, Pembroke, and 

 Cardigan, and it occurs in N. Wales only in Flint and Denbigh, and 

 not in !\Iiel Lanes, but south ot this it is general. It is uncertain 

 whether it occm's in North England or .Scotland, north of \'ork, 

 except in Stirling. 



The Great Chickweed is a good inde.x ot wet soil, tor it cannot 

 grow away trom water. The plant is a hygrophile, without being 

 a marsh or bog plant. It is tound growing in tail clumps along a 

 shaded ditch-side on the roadside, or lining the margin of pool or lake, 

 or more extensively by the side of a stream or river. Here, itself 

 white-flowered, it vies with the large puce flowers of the Great Hairy 

 Willow Herb, or perchance with Water Bedstraw or Water Figwort. 



This is the largest and finest of the .Stitchworts, being tall and 

 leafy, but slender, brittle, and prostrate below, then ascending. The 

 leaves are heart-shaped, with a long point, the lower stalked, the upper 

 stalkless, and hairy along the margin. The branches are alternate, 

 and the plant supports itself l)y aid ot the surrounding vegetation. 



The tlowers are large, white, in the axils, single, and distant; the 

 petals are divided to the base, longer than the calyx. The capsule is 

 larger than the calyx, on turned-back fiower-stalks, and opens by live 

 clefts. The seeds are reddish-brown and rough, about sixty in each 

 capsule. 



The Great Chickweed is often as much as 3 ft. high. The flowers 

 are in bloom in July and August. It is perennial, and may be in- 

 creased by division. The tlowers are larger than in Ccrastiiiiii trivialc, 

 but of the same size as in Ccrastiuiu arvciisc and Stcllaria Holostca. 

 The number of insect visitors and the arrangement of stamens and 

 pistil is intermediate, and as favourable to cross- as selt-pollination. 

 The flowers are proterandrous, the anthers ripening first. When no 



