208 



FLOWERS OF THE SEA-COAST 



Grass Wrack (Zostera marina, L.) 



This is not known in early deposits, though Zostera-\fa& foliage 

 occurs in estuarine deposits, but it is found in plant beds in S. Sweden 

 in Gothland. To-day its distribution is around the North Temperate 

 and Arctic coasts. In Great Britain it is absent from the coast of 

 N. Devon, Cardigan, Merioneth, Denbigh, Flint, Westmorland, Dum- 

 fries, Berwick, Aberdeen, 

 Banff, Mid Ebudes, but is 

 generally distributed else- 

 where, around the coast of 

 other maritime counties, as 

 far north as the Shetlands, 

 and in Ireland and the 

 Channel Islands. 



This is one of the few 

 marine, aquatic plants which 

 grow in salt water at low- 

 water mark, and they are 

 typical of the flora of estu- 

 aries, and coasts which ex- 

 hibit numerous small bays 

 and inlets, especially on 

 sandy and muddy coasts. 



The habit is that of a 

 submerged, streaming sea- 

 weed. The leaves are grass- 

 like, borne on flattened or 

 nearly round stems, and are 

 long, lance-shaped, wavy, 



blunt, with 1-7 nerves, bright green, and entire. The first Greek 

 name indicates their ribbon-like character. 



The flowers are green, enclosed in a spathe or sheath which is like 

 a hollowed-out leaf, on a long, stout flower- stalk, like the leaves, 

 enclosing a spadix with anthers and an ovary, in two series, opposite, 

 the ovary alternating with the stamens, and stalkless. The capsule 

 contains i ribbed seed, and is furrowed, and the seed milky-white. 

 The spadix is not banded and contains many flowers. The top of the 

 spathe exceeds the spaclix. There is no extine in the pollen. 



Grass \Vrack is 1-3 ft. long. It flowers in August and September. 

 Grass Wrack is perennial and propagated by seeds. 



GRASS WRACK (Zostera marina^ L.) 



