LETTUCE 



361 



number of varieties of it which now exist in cultivation, and the 

 very permanent manner in which some of these varieties appear to 

 be established, afford good grounds for the opinion that the plant 

 has been cultivated for a very long time. 



The different varieties present such a diversity in the shape and 

 colour of the leaves, that it is difficult to give a general description 

 of the plant which will be applicable to all its forms. We may 

 suppose, however, and especially from the fact that some Chinese 

 varieties do not form a head, that in its original or natural state 

 the Lettuce forms a rosette of broad and long leaves, somewhat 

 spoon-shaped, and more or less undulated and toothed at the 

 edges. From the centre of the rosette springs a nearly cylindrical 

 stem, which narrows very rapidly and becomes branching at about 

 one-third of its height, furnished with clasping leaves, which are 

 auricled, and become narrower as they approach the top of the 

 stem. The flower-heads are numerous, longer than broad, with 

 pale yellow florets. Seed small, of a long almond shape, pointed 

 at one end, marked with pretty deep longitudinal furrows, and 

 usually either white or black, but sometimes brown or reddish 

 yellow. Its germinating power lasts for five years. 



Good authorities appear inclined to refer all the cultivated 

 varieties of Lettuce to two distinct botanical types, from one of 

 which have been derived the Cabbage Lettuces, properly so called, 

 which have rounded or flattened heads, while the other has been 

 the parent of the Cos Lettuces, in which the head is tall and 

 elongated in shape. We find it difficult to assent to this view of 

 a twofold origin ; in the first place, because the two kinds pass into 

 each other through almost imperceptible gradations ; and secondly, 

 because as soon as they run to seed they present no difference 

 between each other, which is conclusive proof of the identity of 

 their origin. 



We have described the Cultivated Lettuce as an annual plant, 

 because the growth of the flower-stem uninterruptedly succeeds that 

 of the radical leaves which form the rosette, and because the rosette 

 itself is completely formed in a few weeks, or, at most, in a few 

 months. Nevertheless, several varieties are so hardy, that they 

 may be sown in autumn, and, after withstanding the winter, will 

 not run to seed until spring. All the varieties are by no means 

 amenable to this treatment. On the other hand, there is a great 

 deal of inequality in the degrees of readiness with which the 

 different varieties run to seed under the influence of warm summer 

 weather. These differences of constitution and suitability for 

 various seasons have led to the division of the varieties of Lettuces 

 into three classes, from a cultural point of view, viz. : 



I. Winter Lettuces, which, with a little care, will withstand 

 ordinary winters in France, the south of England, etc. 



