2 3 8 



HINTS AND NOTES 



even if the uniform land and sea breezes were 

 not equally influential in this respect. 



Again, the sequence of changes from one 

 type of maritime zone to another is quite 

 definite, and there are few sea-coast types 

 that are to be found inland under other condi- 

 tions, except some Grasses (as Seaside Manna 

 Grass), Buckshorn Plantain, Woad, and Cen- 

 taury, and these are chiefly sandy-soil types. 

 The vegetation of the sea-coast is thus as a 

 whole more or less specialized, and does not 

 grade into inland types. This is an important 

 feature upon which due emphasis should be 

 laid. The occurrence of many inland plants 

 on the sea-coast on the contrary is an equally 

 noticeable feature, e.g. Scarlet Pimpernel on 

 shingle, &c. 



Composite Types of Seaside Vegetation. 

 The title of this section may seem paradoxical 

 compared with the last. But whilst the condi- 

 tions of vegetation are limited to certain types, 

 the types met with upon the sea-coast are 

 sufficiently diverse or composite. Thus there 

 are sandy tracts of sea-coast, and others that 

 are muddy. There are the mouths of estuaries, 

 and alluvial flats or warp. There are again 

 stretches of shingle with peculiarities of their 

 own. Where rocks bound the sea -margin 

 there are diverse types of soil derived from 

 each type of rock. There are the special 

 types of sand-dune, usually mobile, unless 

 well stabilized by dune plants, such as Lyme 

 Grass or Dwarf Willow, as in Anglesey. 



There are again open or closed bays with 

 brackish water in which Grass Wrack, Naias, 

 and Ruppia grow, with characteristic brackish- 

 water Algae and Mollusca. The salt marshes 

 finally form another type, and one with very 

 marked characteristics. In addition to these 

 genuine maritime plant-formations there is 

 a large flora of alien plants which have estab- 

 lished themselves along the coast, on kitchen 

 middens or elsewhere. The neighbourhood 

 of docks and ports is particularly favourable, 

 especially where grain is imported, for the 

 introduction and establishment of such plants. 

 The inland flora again is always encroaching 

 upon the coast flora. So that taken as a 

 whole, though the alien plants and those 

 found near docks and ports rightly belong 

 to other sections, the flora is decidedly com- 

 posite. 



Dry-soil Conditions of Coast Vegetation. 

 The plants that grow by the sea-coast, also 

 called strand plants, are distinguished from 

 the inland types. The latter are adapted 

 to a moderate supply of moisture, and are 

 known as mesophytes, as meadow plants. 

 They also differ from those that are adapted 

 to dry summer conditions and cold or wet 



I winter conditions, or tropophytes, such as 

 deciduous trees, &c. Strand plants are in 

 fact especially adapted to dry conditions. The 



j same applies to the dunes and salt marshes 

 as to the sandy sea-coast. This is due to the 

 fact that in absorbing water, coastal plants 

 would necessarily absorb a large proportion of 

 salt, and since this would upset the balance of 

 nutritive materials, the plant therefore takes 



, up less water than it otherwise would do. 



To compensate for this, the plant has a 

 reduced leaf surface, few of the plants, except 

 Yellow Horned Poppy, Sea Kale, and some 

 few others, developing broad leaves. Most 

 are linear or narrow and oblong. They are 

 also, as a rule, fleshy and thick and suc- 



j culent, e.g. Samphire, Oraches, Sea Holly, 

 Saltwort, &c. 



The stems are equally fleshy and succulent. 

 The herbaceous types, as Sea Elite, Sea Heath, 

 have heath-like, small, short, linear leaves. 



i The majority of the maritime plants are dwarf, 



' and not luxuriant, and many are procumbent 

 or trailing. Other factors are the thick cuticle 



\ or epidermis preventing ready transpiration. 



j The stomata are also sunk in this thick cuticle, 

 assisting the plant in fitting itself to physio- 

 logical drought. 



The sandy and shingly character of the sea- 

 coast, and the wind, cause the substratum on 



| which they grow to be destitute of moisture, 



I and the plants have largely to rely on atmos* 



1 pheric moisture. 



Modern Character of Sea-coast Vegetation. 

 The sand and shingle cast up by the agency of 

 the sea is of purely modern origin. Marine 

 deposits in fact belong to the latest geological 

 period, the recent or Quaternary epoch. 



It is also known that England was con- 

 nected with the Continent in Preglacial times, 

 and during some part of the Glacial period, 

 hence the present maritime flora is of com- 

 paratively modern type. Apart from the records 

 of a few present maritime plants in Glacial 

 and later beds the succession is broken, for 

 apart from Naias, which occurs in the Pre- 

 glacial Cromer Forest Bed, there are no earlier 

 records of marine types that are connected 

 with our present maritime flowering plants. 



Amongst those described, two are found in 

 the Oak Zone in Scandinavia, Sea Rocket 

 and Sea Buckthorn ; three in Interglacial beds 

 in this country, Sea Campion (found to-day, 

 inland, on the hills), Sea Purslane, Sea Milk- 

 wort; and the Sea Club Rush is found in 

 Neolithic beds. The raised beaches and shingle 

 beaches found inland are of modern origin also. 

 Isolation of Maritime Types on Hills. The 

 occurrence of certain typical maritime plants 

 upon inland mountains, and their absence 



