SKIRRIT OF ECONOMIC PLANTS. 379 



tapers upwards from a swollen base, around which are thick 

 projecting buttresses of sufficient widtli to allow of horses being 

 stalled between them. The natives call it Ceiba. 



Silky Oak [G-revillm rohiista), a tree of the Protea family 

 (Proteaceas), native of Queensland, and probably one of the 

 loftiest trees of the family ; it attains a height of from 50 to 

 150 feet, with a diameter of from 6 to 8 feet ; its timber is 

 valuable. A plant introduced into Kew in 182G has attained 

 a large size, and with its much-divided silky leaves presents a 

 strong contrast to the more humble species of the genus, which 

 mostly consist of small shrubs Avitli willow, holly, box, or juniper- 

 like leaves, producing pretty spikes of flowers. 



Silphium of the Ancients. {See Carrot, Deadly.) 



Silphium of Linnaeus. {See Compass Plant.) 



Silver Fir {Picea pectinata), a tree of the family Coniferos, 

 native of Europe and Korthern Asia. It takes its name from 

 its silvery white leaves, and attains a great height, it is even 

 said above 200 feet, and when standing singly is a beautiful 

 tree. A resin is obtained from it, which when purified is called 

 Strasburg Turpentine. The Silver Fir is subject to a disease, 

 especially in Switzerland, which is caused by a fungus, a species 

 of u^cidium, similar to the corn mildew. 



Silver Rod. {See Asphodel.) 



Silver Tree (Zeueadendron argenteum), a sniall tree of the 

 Protea family (Proteacece), with beautiful silvery lance-shaped 

 leaves, native of Table j\Iountain and the Cape of Good Hope. 

 Its vicinity to Cape Town has led to its almost complete extirpa- 

 tion for firewood. Its destruction, however, is now prohibited. 



Simaruba Bark. {See Quassia.) 



Sissoo, a name in India for Dcdhcrgia Sissoo, a tree of the 

 Bean family (Leguminosce), common in Bengal, and extending 

 northward to the Punjab. It is a fast-growing tree, attaining a 

 considerable size. Its timber is strong, compact, and tenacious, 

 of a dark-brown colour, and is used in all works where strength 

 and durability are required. 



Skirrit {Siiom Sisarum), a perennial herb of the Carrot family 



