252 



HINTS AND NOTES 



formation (included together as Eremophytes) 

 being dry-soil types. The Grape Hyacinth 

 (Muscari racemosuni) is a steppe plant. 



The longer vegetative period and greater 

 degree of humidity of chersophytic vegetation 

 distinguish it from the steppe formation, and 

 the bulbous and tuberous plants of the steppe 

 are absent. 



A type of meadow in the Alps is characterized 

 by the dominance of Festuca vallesiaca and 

 Kceleria vallesiaca. This last has recently 

 been recognized in this country. It also 

 includes Poa bulbosa. The Brome meadow 

 on the Alps is dominated by Bromus erectus, 

 common on certain dry calcareous pastures 

 in this country also, and with it also grow 

 Gal him Mollugo, Festuca rubra, F. ovina, F. 

 pratensis, Carex verna, Prunella vuJgaris, 

 Salvia pratensis, &c. These occur in similar 

 situations in this country. 



Bushland or thorn bushland on dry soil 

 consists of Barberry, Hawthorn, Rose, 

 Bramble, or Juniper, and in Scotland of 

 Gorse. This is due to destruction of forest 

 in humid areas on dry soils. The affinity of 

 this natural waste ground to waste places in 

 the ordinary sense is clear. Fern heath with 

 Gorse occurs in the south of England. These 

 formations agree in the dry character of the 

 soil and modified surface features. 



Hedgerows, &c., near Villages, Boundaries 

 of Cultivated Tracts. Taking first the areas 

 immediately around the habitations of man, 

 who is the chief agent in the introduction and 

 dispersal of alien plants, there are the hedge- 

 rows and other kindred spots in close proxi- 

 mity to villages or towns, or the boundaries 

 of cultivated tracts, where certain plants are 

 usually to be found in a large number of 

 similar spots, which occur around almost 

 every village or town. 



The Greater Celandine is one of these 

 plants. Go where one will, it is nearly always 

 possible to discover somewhere on the imme- 

 diate outskirts of a village, in the hedge of a 

 garden, or at the base of a loosely-made wall, 

 a number of individuals of this plant. It is 

 common on sloping banks where other plants 

 do not grow, and where the soil is bare of 

 vegetation. Its acrid juices may make the 

 soil unfitted for other plants around it. Gout- 

 weed and Tansy are further examples. 



Borage, Comfrey, and Bittersweet occur in 

 more open spots away from hedges, close to 

 villages and gardens. These plants un- 

 doubtedly owe their dispersal to artificial 

 causes, being used as remedies for various 

 complaints from the Middle Ages down to the 

 present time. 



Bases of Walls, &c. Walls, which will be 



described in greater detail in Section XII, 

 are in themselves artificial, and support a 

 number of characteristic mural plants that 

 grow in the crevices or on the top, depending 

 upon the rupestral type of habitat. At the 

 base of walls, whether in villages or else- 

 where, a certain type of habitat develops, 

 which supports a typical florula akin to that 

 of waste ground. The soil at the base is 

 usually open. Water drips from the wall-top, 

 forming hollows and loosening the soil. This 

 is inimical to some plants, exposing their 

 rootlets. Fragments of the brick or stone 

 break off, or sand-blasts caused by sand from 

 the macadam may undercut the materials. 



Weeds are removed, especially grass, and 

 quickly-growing annuals and some ubiquitous 

 perennials take their place. The roadscraper 

 disturbs the ground periodically. Shepherd's 

 Purse is one of the most common types, grow- 

 ing at the base of the wall on open ground, 

 and in a variety of similar spots, as on soil 

 denuded for stone heaps, farmyards, &c. 

 Common Mouse-ear Chickweed (also a plant 

 of dry pastures) likewise frequents this habitat. 



Common Chickweed is another familiar weed 

 along the roadside at the bottom of walls. 

 Cut-leaved Dead Nettle often grows at the base 

 of a wall where there is a good thick deposit 

 of road grit. The Hedge Mustard is another 

 plant that is especially fond of this habitat. 

 The Great Plantain, Veronica agrestis, Wall 

 Speedwell (also mural), and Barley Grass may 

 also be found in such situations. The last is 

 especially characteristic. 



Sandy Wastes, Dunes. Certain areas with 

 a loose sandy soil occur here and there which 

 may be described as waste ground, in the 

 sense that they are not open to cultivation 

 and are left in a more or less derelict condition. 

 The plants that grow in such places are 

 usually characteristic of dry sand soil. They 

 include such plants as Stork's Bill, Musk 

 Thistle, mentioned here, and others such as 

 Lotus tenuis, Fuller's Teasel, Evening Prim- 

 rose, Hare's Foot Trefoil, Bird's Foot Trefoil, 

 Vernal Whitlow Grass, Cornflower, Mallow, 

 and many other plants of doubtful origin, such 

 as Treacle Mustard, Lepidium Draba, Sisym- 

 brium pannonicuin, &c. 



This type of mixed association is similar to 

 the vegetation that may establish itself upon a 

 fixed dune after the fixation of the sand by 

 Marram has been completed. When this is 

 the case a large number of inland plants 

 commence to appear, and the ordinary mari- 

 time vegetation of the sand dunes, which is 

 not very extensive (in species), tends to dis- 

 appear. 



The effuse or much - branched Oraches, 



