256 



HINTS AND NOTES 



Musk Thistle, IMilU Thislle, Chicory, Viper's 

 Bugloss, Mullein, Creepiiitj Toadflax, Fat 

 Hen. These later-flowering plants bear more 

 flowers or florets than the earlier-llowering 

 plants, which opens i.i[> a hitherlo unrevealed 

 principle. 



The Duration of Waste-ground Plants. — 

 Intimately connected as the flowering periods 

 and duration of all plants are, as has been seen 

 in the case of the groups of plants chosen to 

 illustrate each habitat, no section reveals this 

 more forcibly than the present one. 



The plants that make it up are of four types : 

 annuals, biennials, triennials, and perenjiials, 

 and the three former greatly exceed the last. 

 It is to be emphasized here that the annuals 

 do not bloom till June. They have to produce 

 from seed all the organs necessary for plant- 

 life with growth and power of reproduction ; 

 whereas perennials have a root and rootstock 

 and stem base already made, and in some cases 

 the leaves persist, or at least the branches, whilst 

 a fresh stock of radical leaves often arises in 

 autumn to protect the new aerial stem or shoot 

 of next year, e.g. Sisynihriitm, Barbarea, Bal- 

 lota, Rtimex, &c., and in a mild winter these 

 survive, and serve as an asset in spring. 



The annual plants described are Shepherd's 

 Purse, Mouse-ear Chickweed, Melilot, Stink- 

 ing Mayweed, Groundsel, Musk Thistle, 

 Hawksbeard, Purple Dead Nettle, Fat Hen, 

 Wall B.irley. The biennial plants are Bur- 

 dock, Spear Thistle, Hound's Tongue, Viper's 

 Bugloss, Mullein, all plants that are clothed 

 with down or hairs. Milk Thistle and Hen- 

 bane .ire triennial. Belladonna is also appa- 

 rently biennial in some cases. 



The perennials include Greater Celandine, 

 Mallow, Stork's Bill, Goutvveed, Tansy, 

 Chicory, Bittersweet, Belladonna (usuallv). 

 Creeping Toadflax, Toadflax, White Dead 

 Nettle, Good King Henry, Dairy Maid's Dock. 

 It is curious that in some genera only one 

 species, e.g. Good King Henry, should be 

 perennial, the rest annual. It is highly pro- 

 bable lh.it all were perennial at first. 



Pollination of Waste-ground Plants. — The 

 mixture of waste-ground plants, which in 

 many cases consists of plants distributed ow- 

 ing to certain properties thev possess, causes a 

 considerable diversity in their degree of attrac- 

 tiveness to insects, apart from the possession 

 of honey, pollen, or sweet juices. 



As a whole the flowers mav be said to be 

 conspicuous and brilliantly coloured, and some, 

 as the Mallow, are wide open and large. 

 Rather large flowers or flowerheads are also 

 not uncommon, as in Greater Celandine, 

 Melilot, Tansy, all yellow. Musk Thistle, 

 Spear Thistle, Milk Thistle, Chicory, Viper's 



Bugloss. Three poisonous plants, Bitter- 

 sweet, Belladonna, Henbane, have noxious 

 aromas, and so has Hound's Tongue, and ab- 

 normal colours. The closed flowers of the 

 Toadflaxes, and hooded flowers of the Dead 

 Nettles, are all adapted to insect visits. 



Shepherd's Purse and .Mouse-ear Chickweed, 

 with inconspicuous small flowers, are adapted 

 equally to self- or cross-pollination, and Stork's 

 Bill also, as well as Groundsel. Goutweed, 

 .Stinking .Mayweed, Burdock, Hawksbeard, 

 all have more or less conspicuous, though not 

 such brilliant or large flowers. In .Mouse-ear 

 Chickweed and Mallow and Stork's BiH the 

 anthers are ripe first. The iSIusk Thistle is 

 a dioecious plant. In the I'urplc Dead Nettle 

 the anthers and stigma mature simult.meouslv, 

 and the .same applies to Knotgrass, which has 

 also cleistoganiic flowers. The Goosefoots, 

 I'at Hen, and Good King Henry, the Dairy 

 Maid's Dock, and Wall Barlej- are pollinated 

 by the agency of the wind. The rest are 

 adapted to insect visits, or failing such thev 

 are in some cases self-fertile. 



The Dispersal of Seeds of Waste-ground 

 Plants. — The diversity of habitats of w.iste- 

 ground plants is perhaps correlated with the 

 different modes of dispersal of the seeds. As 

 a whole the habitats are not open, and require 

 special means for the dispersal of the seed.s. 

 The prevalence of annuals demands the pro- 

 duction of a large number of seeds, and a large 

 proportion of the plants, as the Docks and 

 Goosefoots, produce a considerable number ot 

 flowers. The gregariousness of many of the 

 plants also within limited areas has an impor- 

 tant bearing upon the mode of dispersal. 



The agency of man in distributing such 

 aliens independently of the mode of dispersal 

 to a large extent determines their distribution. 

 Railways and canals are important agents in 

 dispersal ; but principally there is the carrying 

 on of agriculture and the carriage of crops 

 from one spot to another, from the field to 

 the stackjard. The manuring of ground also 

 plays an extensive part in the spreading of 

 aliens or other types of waste-ground plants. 

 .Some plants depend upon their own mode of 

 dispersal, as Greater Celandine (which is also 

 dispersed by ants). Shepherd's Purse, M.illow, 

 Stork's Bill (in which the seed are dispersed by 

 an elastic movement, and in which the long 

 ;iwn is hygroscopic), .Melilot, Viper's Bugloss, 

 Henbane (also wind-dispersed). Mullein, Cree[)- 

 ing and Common Toadflax, Purple Dead 

 Nettle, White Dead Nettle, Fat Hen (also 

 wind-dispersed). Good King Henry (also wind- 

 dispersed). In many cases the seeds of fruits 

 are small ; and in other cases, as in numerous 

 Composites, provided with hairs and dispersed 



