488 



SUB-CLASS IV. -MONOCHLAMYDEjE. 



664. In this sub-class, the perianth never consists of more 

 than a single whorl, which may be considered in the light of a 

 calyx or of a corolla. In many instances there is no vestige of 

 either one or the other, and the fructification is reduced to its 

 simplest possible condition. It is interesting to remark that, 

 although this group does not contain nearly so many species dis- 

 tinguished for their peculiar properties, as do the former ones, 

 yet it includes a large proportion of those, whose stems furnish 

 us with valuable timber, for example, the Oak, Elm, and Fir 

 tribes ; so that it would seem, as if the suppression of some of 

 the organs of fructification, by which the race is multiplied, were 

 favourable to the development of the individual structure. The 

 first two orders to be noticed are of no great importance in 

 themselves ; but, as they contain several British species, it is 

 desirable not to pass them by. 



665. Of the order CHENOPODEJ:, or Goosefoot tribe, the com- 

 mon Goosefoot, so named from the peculiar form of its leaves, 

 may be considered as the type. It has a perianth composed of 

 five adherent portions, at the base of which, and opposite to the 

 segments, are inserted five stamens. The ovarium is superior 

 and one-celled, and crowned with two stigmas ; it contains but 

 a single ovule, which is attached to the base of the cavity. The 

 plants of this order inhabit waste places in all parts of the 

 world, abounding mostly in the northern parts of Europe and 

 Asia ; they are mostly considered rank weeds ; but some of them 

 have been rendered by cultivation very serviceable to Man. 

 Some foreign species are used medicinally, in the countries 

 where they grow. The most important products of this order, 

 however, are not of a medicinal, but of a nutritious character. 

 Of several species, such as Spinage, the leaves and stems are 

 used as potherbs ; of others, such as Beet, the root becomes very 

 fleshy under cultivation, and affords a large quantity of whole- 

 some aliment. One species of Beet is cultivated in England 



