ii8 A TEXT-BOOK OF BOTANY. 



A manna is also yielded by Cedrus Libani and Larix decidua. The 

 latter is known as " Briancon Manna," and contains melizitose. 

 The bark of some species furnishes valuable tanning material, as 

 that of the hemlock spruce (Tsuga canadensis). 



Thuj, 



r PlG. 76. Fruiting twig of common Juniper (Juniperus communis), of Red Cedar or 

 Savin (Juniperus virginiana), and young twig of White Cedar or Arbor Vitae (Thuja occiden- 

 talis). From "Minnesota Trees and Shrubs." 



The Coniferse yield large quantities of volatile oils, resins, and 

 allied products which are used both in medicine and the arts. 

 A number of them yield turpentine (see Vol. II). Larix decidua 

 of the Alps and Carpathian mountains yields Venice turpentine. 

 Abies balsamea is the source of Canada turpentine or balsam of 



