552 BDLLBUSH TRIBE. ARUM TRIBE. 



order differ from the Bur-reed in some of these particulars ; in 

 the Bull-rush, for example, the calyx is entirely wanting, being 

 merely replaced with a quantity of delicate black hairs ; and in 

 some species there are but three stamens. The essential character 

 of the order is derived from the incompleteness of the flowers, 

 and especially from the structure of the ovarium, in which no 

 trace of the number three can at any time be detected. 



728. The Typhacese are principally confined to the northern 

 hemisphere, and few are found in equinoctial regions. They are 

 not of much direct importance to Man, possessing no properties 

 which differ from those of ordinary Rushes and Sedges. Like 

 some of these, they give an appearance of luxuriance in cold and 

 damp situations ; and they afford fodder for cattle, though poor 

 and scanty, in situations which are otherwise barren. 



729. Another group of incomplete Endogens is that of ARA- 

 CEJE, the Arum tribe. Of these, one species is extremely common 

 in our hedges, and is known by the name of TVake-robin, or (to 

 children) by that of Lords-and-Ladies. The leaves of this group 

 seem to offer an exception to the general parallel-veining of 

 Endogenous leaves ; rather resembling the reticulated leaves of 

 Exogens. But this is more in appearance than in reality ; since 

 it will be observed on careful examination, that the veins are 

 branched (like those of the Ferns) rather than netted, and are in 

 great measure destitute of the lateral minute branchlets uniting 

 with each other, to which the appearance of Exogenous leaves is 

 chiefly owing. The common species of our hedges is distin- 

 guished by usually having purple spots upon its leaves. Many 

 Arums have large tuberous underground stems ; which, although 

 acrid and even poisonous when raw, may be rendered fit for food, 

 by slicing, washing, and boiling. The flowering system of the 

 Arums presents many points of interest. The first thing we 

 notice, is the large spathe wrapping round a central column or 

 spadix, on which the minute flowers are crowded. In the com- 

 mon British Arum it is green; but in others it presents a most 

 beautiful variety and richness of colour. Sometimes it opens 

 widely like an inverted bell, the mouth being a foot or more in 

 diameter; in other instances, the summit is prolonged on one 



