CORNFIELDS 



231 



fields and cornfields and allied cultivated tracts 

 is their accessibility. At least the margins of 

 such fields usually grassed over may be exam- 

 ined. 



They were once like meadows occupied by 

 woodlands, and in many cases common land. 

 Their expansiveness is similar (though they 

 are less continuous) to that of meadows. The 

 cornfield plants are sun plants, though the 

 ground flora, as in meadows, is obscured by 

 the higher zones. This is one of their most 

 marked characteristics. As in the case of 

 meadows, some are lowland, some are upland, 

 but few range above an altitude of 1000 ft., 

 whereas meadows occur at higher levels. 



The Impermanence of Cornfields. There is 

 a marked contrast between the longevity of 

 the meadow and the cornfield. In the former 

 there is but a slight disturbance of the main 

 conditions when a meadow is converted into 

 pasture, or vice versa. But in a cornfield 

 there is the yearly ploughing, harrowing, 

 sowing, drilling, rolling, hoeing, cutting, 

 reaping, and harvesting, and a repetition of 

 this process for the next crop. 



It is important to remember that the plants 

 of especial interest to the botanist in a cornfield 

 are treated as weeds, and are there on suffer- 

 ance, their eradication (total or partial) depend- 

 ing upon the diligence or laxity of the farmer. 

 In the meadow no such artificial selection 

 or division into weeds or crops takes place, 

 if one excludes thistles and a few other plants 

 that are distasteful as hay, or useless, e.g. 

 Yellow Rattle. Hence one reason for the 

 ephemeral character of the denizens of the 

 cornfield, or colonists as they are called. 



Another equally important factor in regulat- 

 ing the permanence of the cornfield flora is 

 the rotation of crops, of which more is to be 

 said later. Owing to the exhaustion of the 

 soil by certain crops of a highly-specialized 

 character, such as wheat, the plants that grow 

 in cornfields are rendered unstable, because 

 each different type of crop brings with it in the 

 sowing, and by reason of the different method 

 of tillage, a different set of weeds. 



A further reason for the short life of corn- 

 field plants is the possible return of arable to 

 pasture or fallow. All these facts should be 

 studied in detail. 



Cornfields and Woodlands : some Similarities. 

 In describing the tiers of plants in a meadow 

 attention was drawn to the analogy between 

 this and that noticed in woodlands. An even 

 more marked similarity exists between this 

 arrangement of crops and other plants in a 

 cornfield pure and simple and that observed 

 in woods. In this case the tree zone is repre- 

 sented by the corn itself and those giants of 



the cornfield, such as Corn Cockle, Corn Sow 

 Thistle, &c. , which tower above their fellows. 

 This, of course, obtains only in the summer, 

 when the stalks are tall and close set. They 

 provide an ample shade for the Igwer zones of 

 plants. 



Intermediate between the tree zone and the 

 lowest zone (ground flora) is a middle zone, 

 comparable with the scrub of the woods, 

 which consists of such medium plants with a 

 widespread pyramid habit as Corn Buttercup, 

 or the later Fool's Parsley. These have 

 narrow leaves, adapted to growth amongst 

 close, erect plants such as cereals, an adapta- 

 tion not noticed definitelv so far. Below come 

 the trailers, dwarf plants, such as Scarlet 

 Pimpernel, and short erect plants (with linear 

 leaves) as Least Spurge. Rosette plants, as 

 Great Plantain, are found like the Daisy 

 covering the surface. There are some 

 climbers, too, as Corn Bindweed or Small 

 Convolulus. 



Denizen and Colonist Flora. The plants 

 which are found in cornfields are a motley 

 assemblage. Some are pure aliens and of 

 merely sporadic occurrence, as Larkspur, 

 Gold of Pleasure, Venus's Looking Glass. 

 Charlock is a denizen. Corn Buttercup, Red 

 Poppy, Fumitory, Candytuft, Corn Cockle, 

 Venus's Comb, Corn Marigold, Cornflower, 

 Snapdragon, Wild Oat, and Darnel are 

 colonists, which were defined by Watson to 

 be weeds of cultivated land, by roadsides of 

 about houses, only existing here as long as 

 human agency provides suitable conditions. 

 The denizen is apparently indigenous, but 

 liable to some suspicion of having been origi- 

 nally introduced by man, as the Horse-radish 

 and Melilot. The alien plants are certainly 

 or very probably of foreign origin, though 

 now more or less distinctly naturalized, as 

 among trees the Sycamore and the Bird 

 Cherry. The casual was accidentally im- 

 ported or strayed from cultivation, not truly 

 naturalized, and generally unable to maintain 

 itself from year to year, as the Caraway, and 

 perhaps Larkspur. 



Native plants are believed to be truly abo- 

 riginal species, and amongst cornfield plants 

 perhaps the following are native: Scarlet 

 Pimpernel (this grows also in woods and on 

 shingle), Corn Gromwell (Common Gromwell 

 grows by the roadside), Hemp Nettle, also a 

 wayside plant. 



The Limits of Cultivation. Several reasons 

 determine the limits between which cultivated 

 plants will grow and thrive. These in general 

 are similar to those which regulate the distri- 

 bution of all plants, but they apply in a more 

 marked degree. For the cultivated cereals, 



