210 SELECT PLANTS FOR INDUSTRIAL CULTURE 



differing considerably in their scent. A crystalline substance is 

 also obtained from this and similar species. 0. canum (Sims) is 

 closely allied. Valuable, like many other aromatic Labiatae, for 

 bees. 



Ocimum gratis simum, Linne. 



Recorded from India, the South Sea Islands, and Brazil, as 

 indigenous. Somewhat shrubby. This is also a scent plant like 

 the following, and is one of the best of the genus. 0. viride 

 (Willd.) from tropical Africa seems a variety. 



Ocimum sanctum, Linne. 



Arabia, India, tropical Australia. A perennial herb. The odour 

 of the variety occurring in North Australia reminds of anise ; the 

 smell of the variety growing in East Australia resembles cloves. 

 O. tenuiflorum, L., seems to be another variety. Probably other 

 species, cis- as well as trans- Atlantic, can be used like Basil. 



Ocimum suave, Willdenow. 



East Africa. A scrubby species. 



Oenanthe stolonifera, Candolle. 



Japan, China, India. This swamp-herb is there used for spinage. 



Olea Europsea, Linne.* 



The Olive-tree. From South- Western Asia ; naturalized in the 

 countries around the Meditteranean Sea. A tree not of great 

 height, but of many centuries duration and of unabating fecundity. 

 In Corfu, however, it grows to a height of sometimes 60 feet, and 

 forms beautiful forests. The well-known olive oil is obtained from 

 the fruit. Certain varieties of the fruit, preserved in vinegar or 

 salt-liquid before perfectly ripe, are also much used for the table. 

 For this purpose the fruit is generally macerated previously in 

 water containing potash and lime. The gum-resiri of the Olive- 

 tree contains the crystaline olivil. The oil of the drupaceous fruit 

 is a most important product of countries with a temperate climate. 

 Its chemical constituents are : 30 per cent, crystalline palmitin ; 70 

 per cent, olein, through which olive oil belongs to those kinds which 

 are not drying. In pressing, the kernels must not be crushed, as 

 then a disagreeable taste will be imparted to the oil. The wild 

 variety of the olive tree has usually short blunt leaves and thorny 

 branches. Long-continued droughts, so detrimental to most plants, 

 will affect the olive but slightly. It thrives best on a free, loamy, 

 calcareous soil, even should it be strong and sandy, but it dislikes 

 stiff clay. Proximity to the sea is favourable to it, and hill-sides 

 are more eligible for 'its culture than plains. The ground must be 



