254 



HINTS AND NOTES 



vitality occur, and germinate on the moist and 

 warm manure -heap. Apart from this, the 

 wind-scattered seeds previously mentioned tend 

 to grow luxuriantly in the refuse manure 

 scattered here and there. 



The following plants are characteristic : 

 Shepherd's Purse, Common and Round- 

 leaved Mallow, Melilot, Black Mustard, White 

 Mustard, Burdock, Spear Thistle, Chicory, 

 Hawksbeard, Dairy Maid's Dock. Others 

 are Scarlet Pimpernel, Veronica Tournefortii, 

 Corn Sow Thistle, Poppies, Charlock, &c. 



Gateways. The relationship of gateways to 

 the highways, and their characteristic florula, 

 have already been mentioned (under Section VI); 

 but gateways are not confined to highways, 

 though they are naturally more frequent there 

 than elsewhere, comparatively speaking. 



The plants that occupy such ground owe 

 their position on both sides of the gateway to 

 their dispersal by much the same method as 

 plants along the cart-road. The foddering of 

 live stock around a gateway is again a constant 

 source of distribution of plants characteristic 

 of this type of artificial habitat. 



The following plants are generally to be 

 found in proximity to gateways, viz. : Knot- 

 grass, Great Plantain, Charlock, Wart Cress, 

 Dairy Maid's Dock, Scentless Mayweed, Bur- 

 dock, Groundsel, &c. 



Quarries, Open Workings, &c. The quarry 

 is an artificial exposure of rock, or loosely com- 

 pacted or clayey beds, which is opened up for 

 economic purposes. Compared with natural 

 exposures of rocks in cliffs, or upon hills, or 

 other places where there is a natural outcrop, 

 the flora is on the one hand similar, or on the 

 other dissimilar. 



The similarity is due to the colonization of 

 such exposures by plants native to the par- 

 ticular type of rock or soil. The form of the 

 exposure determines the type of plants that 

 will more or less naturally find a foothold 

 there. In some cases crevice plants, or those 

 that grow upon bare patches of rock, quickly 

 appear, and flourish as luxuriantly as in natural 

 exposures. The presence of springs or the 

 dripping character of the rock will determine 

 the presence of others. The dissimilarity be- 

 tween the flora of a quarry and that of a 

 natural exposure of rock, &c., is due to the 

 presence of numerous weeds or plants, alien 

 to the locality or rock soil, which occur in 

 varying proportions in the former type of 

 habitat. 



The mode of introduction of such plants is 

 not easy to determine, for this may be diverse. 

 It is highly probable, however, that the wind 

 plays a considerable part in this respect. Rock- 

 faces act as barriers to the further dispersal of 



wind-sown plants, as to the dissemination of 

 the fruits and seeds. Probably the plants more 

 or less native to the district are dispersed by 

 this means. But in a quarry there are fre- 

 quently a number of other plants, obviously 

 brought from a distance in some cases 

 foreigners or true aliens that are undoubtedly 

 brought by other agencies. 



Chief amongst these is the horse traffic in 

 quarries, and the dispersal of fodder plants for 

 this reason. Birds may disperse some plants 

 with indehiscent fruits, as quarries are favourite 

 resorts of birds. Foxes and other mammals, 

 e.g. rabbits, may do the same by carrying the 

 seeds or fruit in the mud on their feet, in these 

 last two cases from no great distance. 



Deadly Nightshade is sometimes found in 

 quarries. Other plants are Dyer's Weed, Rose- 

 bay, Anthyllis, Barbarea prcecox, Melilot, Flax, 

 Senecio viscosus, Hare's Foot Trefoil, Trifolium 

 incarnatum, T. ochroleucon, Lucerne, &c. 



Allotments, Gardens, &c. Allotments and 

 gardens are cultivated tracts which, however, 

 have waste places contiguous to them, and the 

 weeds in the garden are eradicated and turned 

 out, unless they are burnt as manure, and per- 

 petuate themselves upon the outskirts. The 

 garden is a particularly suitable spot for the 

 growth of the less sturdy, succulent herbaceous 

 annuals with more dominant and vigorous 

 plants that form wide associations. Their 

 occurrence or frequency even in such spots is 

 largely sporadic, their societies being small 

 and discontinuous, and as a rule they do not 

 form wide or large or permanent associations. 



The worst conditions that such plants have 

 to contend with are periodical multi-annual 

 eradication and the dominance of the cultivated 

 plants. All the other conditions make for 

 their perfection, and it is surprising that they 

 have retained, so far as we know, their char- 

 acters under such artificial conditions. 



There are a large number of plants common 

 to garden ground, such as Wormwood, 

 Groundsel, Milk Thistle, Mullein, Red Dead 

 Nettle, White Dead Nettle, Fat Hen. Other 

 common types are Cut-leaved Dead Nettle, 

 Grey Speedwell, Henbit Dead Nettle, the 

 terrestrial form of Amphibious Knotgrass, 

 Fool's Parsley, Orache, Creeping Thistle, 

 Twitch, Annual Meadow Grass, &c. 



Manure Heaps, Kitchen Middens, &c. Apart 

 from the manure heaps that are found in farm- 

 yards, there are others in fields, &c., but both 

 agree in the conditions which give rise to the 

 appearance of the plants that are especially 

 found in such places. To a slight extent a 

 manure heap acts as a barrier to, or receiving- 

 house for, the seeds of plants blown thither by 

 the wind. But this does not account for the 



