212 A CONTRIBUTION TO, ETC. 



THE GENUS EUCALYPTUS. 



rp HIS genus, which comprises the most of our forest trees, is a 

 very remarkable one, and has long been a source of perplexity 

 to the systematic botanist. The word Eucalyptus is derived from 

 eu "well," aR&ftalypto "to cover," in allusion to the operculum or 

 lid which covers the calyx until the stamens are fully developed. 

 According to the Linnean system, the genus belongs to the class 

 Icosandria, order 3onogynia } and according to the natural system, 

 to the order Myrfacece. The flowers have no petals, and the 

 stamens which are very numerous, are with few exceptions, white, 

 whilst the tube of the calyx is permanent, and the capsule three, 

 four, five, or six celled. Generally speaking, the leaves are alter- 

 nate, but in some species they are opposite, and in others, they 

 are alternate and opposite on the same tree. The arrangement 

 of the flowers is for the most part in umbels, varying very much 

 in size, as well as in the number of the florets, and these umbels 

 are sometimes axillary or lateral, and sometimes corymbose or 

 paniculate. Being evergreens, and probably lasting for many 

 generations, the species of Eucalyptus undergo many changes in 

 their appearance, for whilst some of them are wholly or partially 

 covered with bark in their youth, and become smooth as they 

 advance in years, nearly all of them vary in the shape and size of 

 their leaves in proportion to their age. As a general rule, the 

 leaves are longer and broader on the young trees, whilst in some 

 species they are first opposite, and then alternate. Being fixed 

 vertically, instead of horizontally, they afford but little shelter 

 from the burning rays of the summer's sun, or from the drench- 

 ing showers which sometimes overtake the weary traveller ; and 

 on the whole, an Australian forest presents a dull and unvarying 

 aspect, uninfluenced by " the bright fresh verdure of spring, or 

 the gorgeous and variegated tints of Autumn." And yet our 

 Eucalypti are of immense importance, whether considered in 

 reference to the value of their timber, the medicinal properties of 

 their barJ\ and resins, or the essential oil of their leaves ; whilst 



