Varieties. 
Name. 
History. 
Agricultural 
value. 
136 
the teeth are fine, lanceolate and acute; the two upper are slightly longer than the others (figs. 1 and 2). 
The corolla is white or rose-coloured, and its parts are very slightly united. The standard (figs. 1, 
2,3) has a broad claw, which partially embraces the other petals; its limb is somewhat erect, and 
folded along the median line. The claws of the other petals, which form the wings (figs. 1 to 4), are 
adherent, for the greater part of their length, to the stamen-tube.. The limb of each wing has a 
vesicular outgrowth from its base, directed backwards and transversely, over the stamen- tube. At a 
point in front of this the wings adhere to the keel. The keef (figs. 5 and 6) is open, and contains 
the anther and the free portions of the stamen- filaments. The ovary is long and contains three or 
four ovules; the style is curved upwards, and sufficiently long to bring the stigma beyond the anthers 
(fig. 7). 
Experiment has proved that white clover cannot be efficiently fertilised without the aid of insects. 
One of Darwin’s experiments showed that ten heads of flowers, visited by bees produced 10 times as 
much seed as an equal number of heads protected from such visits by a net. Another experiment showed 
that 20 capitula covered by a net produced only a single bad seed, whereas an equal number of capitula 
visited by insects produced 2290 seeds. These experiments show that white clover can only be self- 
fertilized to a very slight extent, and that consequently most of the seed is produced by cross-fertilization. 
White clover like red clover is adapted for insect fertilization. There are, however, several important 
points of difference between the two. In the case of white clover, the petals do not unite to form a 
long tube, and the calyx tube, — by the length of which the amount of opening of the petals is deter- 
mined — is only 3 mm. long. These arrangements allow insects with short probosces to have ready 
access to the honey. The honey is secreted at the base of the stamen tube. Two narrow slits lie 
one to the right and one to the left, at the base of the upper free stamen; the honey is sipped by 
the insect through these two slits. 
As in red clover, so here, the insect lands upon the wings of the flower; its weight presses 
down the wings and the keel, which adheres to them; the anthers and stigma are thus laid bare and 
come into contact with the body of the insect, The stigma receives pollen brought from another flower 
on the insect’s body, and, at the same time, more pollen becomes attached to the under surface of the 
insect’s head. When the insect flies away, fertilization has been accomplished and the parts of the 
flower return to their normal position. 
The fruit is a flal pod, much longer than the calyx, and crowned by the persisting style. The 
pericarp is thin and contains three to four seeds (fig. 8). 
The seed resembles that of alsike, but the radicle occupies almost the whole edge (figs. 9 and 40); 
the colour is sulphur or orange yellow. | 
According to Alefeld, two varieties can be distinguished, viz: 1. the wild variety Trifolium repens 
sylvestre, and 2. the cullivated variety Trifolium repens cultum. Botanically, these varieties are not 
distinct. The cultivated variety is, however, twice as high as the other. It has been stated on good 
authority, that, in upper Italy, the wild variety lasts longer, and is less sensitive to extremes of climate 
than the cultivated form imported from the North. In this respect, wild white resembles wild red clover. 
This plant is variously known as white or Dutch clover, white trefoil, creeping trefoil, etc. 
For a long time, it has been cultivated in Holland, hence the common name Dutch cloyer. From 
Holland, its culture spread, like that of red clover, to Mayence, and the interior of Germany. Langethal 
proves from historical evidence, that before 1759, seed of white clover was obtained from Mayence by 
the agriculturists of Holstein, for the purpose of improving their pastures. In England, it was in cul- 
tivation at the beginning of last century. Ils introduction into. Switzerland is of recent date. 
White clover is indispensable for the formation of pastures on low-lying lands. It 
lasts for three or four years, and when the soil is good, even longer. Although the yield is 
less, it is superior in several respects to red clover: — it thrives on soils of inferior quality, 
stands depasturing, liquid manure is: more suitable to it, the nutritive value is higher, and 
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