73 



I well know that it is inconvenient to name as legitimate species forms of hybrid origin, which hava 

 been produced under cultivation. But it is also very inconvenient not to clearly and simply indicate 

 plants distinguished by horticulturists and agriculturalists who propagate them. 



It is also a difficult matter for botanists — the presence of a new species of Eucalyptus, foreign to 

 Australia, and reproducing itself like a native plant in North Africa. That is, however, the case of 

 E. algeriensis. 



E. algeriensis is an example of acclimatisation by means of hybridisation; the hybrid descent 

 offers more facility, by its variations it has a greater facility for adapting itself to a new milieu. 



Here is a description of this hybrid : — 



E. algeriensis Trabut. Rev. Hort. Alg., 1904. E. rostrata x rudis PI. xii. 



Lofty tree with a pyramidal shape when young, trunk with smooth bark coming away in pieces ; 

 leaves glaucescent, pendent, straight or falciform, lanceolate, oval, large on young specimens; inflorescence 

 in axillary umbels of seven to nine flowers, rarely more ; flowers pedicellate, white with an operculum 

 terminated by a short umbo, capsule small, exsert, exceeding the calyx-tube by a little less than half, and 

 opening by erect valves. 



E. algeriensis differs from E. rudis in its smooth trunk, its smaller flowers, in its hemispherical 

 operculum, not rostrate, or only shortly rostrate; it differs ft first sight from E. rostrata in its white buds, 

 like those of E. rudis. E. rudis flowers in winter till December, E. algeriensis flowers in the spring, 

 while E. rostrata only flowers in July-August, and has a special odour. 



The winter flowering of E. rudis seems an obstacle to its pollination by E. rostrata, which flowers 

 iu summer, but it is observed in E. rostrata, as in E. rudis, that there are several delayed flowers, which are 

 sufficient for a cross-pollination. The number of E. algeriensis trees to-day is very considerable. There 

 exists notably a large number at the Forestry Station at Bainen, and the Forestry Service, which has 

 recognised its merit, has propagated it for several years as Red Gum. (This Australian name is in the 

 original.) 



In this group of Eucalypts, after the fall of the operculum, the stigma emerges above the stamens 

 when bent back ; also at this time cross-fertilisation is very easy. 



If one examines the Eucalypts which reproduce themselves spontaneously, especially along the 

 banks of streams, one will recognise that they belong to this species of hybrid origin. It is for this 

 reason that the name algeriensis has been chosen. In the near future this tree will take an important 

 place amongst the spontaneous vegetation of Algeria, where it is well acclimatised and naturalised. 



The wood of E. algeriensis does not differ from the wood of other Red Gums. It is a red or pink 

 timber ; it is easier to work than that of E. globulus, with straighter fibre, and less subject to split. 

 E. algeriensis seems to accommodate itself to all soils, but it prefers those which are somewhat damp. 

 At the Duperre Railway Station can be seen one of the largest of Algerian Eucalypts, which is 

 E. algeriensis. 



This hybrid must have been produced as the result of the first sowings of Red Gum from seed of 

 Algerian origin, for one finds it in most of the plantings made about 1880. There are some specimens 

 of it with a trunk from 2-50 to 3 metres in circumference. 



With reference to Dr. Trabut's remarks re species which pass as Red Gum in 

 Algiers, it is not proper to include E. rudis in such a list. It is not known as Red Gum 

 in Australia, its timber being rather pale and very inferior. See Part XXXIII, p. 75 

 of the present work. 







