324 The Philippine Journal of Science ms 



ANISOPTERA CURTISII Dyer. Dagang. (Plate 15.) 



Gross features. — For color of the wood see group character- 

 istics. The wood is very similar to that of A . thurifera in general 

 appearance, but is of somewhat finer texture; specific gravity, 

 0.707. 



Microscopic features. — Vessels medium large to large, 40 to 

 235 ft (average, 158) in diameter, rounded or ovoid in trans- 

 verse section, diffuse. Tracheids wanting. Fiber tracheids 

 as in A. thurifera. Libriform fibers numerous, 26 by 1,270 /* 

 with walls 8 /x in thickness, irregular in arrangement; stone 

 cells with bordered pits occasionally present. Vertical paren- 

 chyma less conspicuous than in A. thurifera. Resin cysts 

 rounded in transverse section, diffuse. Idioblasts wanting. 

 Wood rays heterogeneous, smaller than in A. thurifera, 5 by 37 

 cells in transverse section. 



Remarks. — Used for the same purposes as palosapis where 

 cheapness is the prime factor rather than strength and durabil- 

 ity. Dagang is of more-restricted distribution than A. thuri- 

 fera, but has been reported in Luzon from Pangasinan, Nueva 

 Ecija, Laguna, Tayabas, and Camarines, and in Negros and 

 Polillo. 



THE LAUAAN GROUP 



The lauaan group is the product of the genera Pentacme, 

 Parashorea, and Shorea, the woods of which are the most im- 

 portant source of cheap structural timber in the Islands, and 

 constitute the real forest wealth of the Philippines. They are 

 among the largest of the dipterocarps, attaining a height of 

 60 meters and a diameter of 2 meters, and supplant the pines 

 and other conifers in the local markets. As a group, lauaans 

 are the least durable of the dipterocarps. 



Gross features.— Sapwood grayish white, medium wide, sub- 

 ject to blue stain; heartwood varying from pale yellow to dark 

 red. Texture coarse to very coarse. Pores medium to very 

 large. Resin cysts in interrupted concentric lines, or both 

 zonate and diffuse. Grain commonly crossed. Wood soft to 

 medium hard, light to moderately heavy; specific gravity, 0.340 

 to 0.720. 



Microscopic features.— Vessels medium to very large, 194 to 

 329 fi in diameter, tyloses inconspicuous. Tracheids few, con- 

 fined to the immediate vicinity of the vessels. Fiber tracheids 

 absent or at most inconspicuous. Libriform fibers with more 

 or less regular radial arrangement, 22 to 28 by 1,360 to 2,020 M , 



