22,s Reyes: Woods of the Philippine Dipterocarps 319 



Key to well-established commercial groups of Philippine dipterocarp woods. 



1. Resin cysts diffuse, not connected by parenchyma, occurring scattered; 



pores often filled with whitish resin 2. 



Resin cysts in concentric rings, more or less connected by light bands 

 of parenchyma; pores very seldom if ever filled with resin 4. 



2. Wood coarse textured; vessel lumina open, visible to the naked eye; 



specific gravity generally not over 0.80 3. 



Wood very fine textured; vessel lumina very small, not visible to the 

 naked eye; specific gravity over 0.85 Narig group. 



3. Wood pale white to yellowish, occasionally with pinkish or reddish 



tinge Paiosapis group. 



Wood reddish to reddish brown, often with distinct odor of resin. 



Apitong group. 



4. Wood coarse textured, soft to moderately hard, light to moderately 



heavy; specific gravity generally not over 0.60 Lauaan group. 



Wood medium to fine textured; hard to very hard, heavy to very heavy, 

 specific gravity generally over 0.70 - 6. 



5. Wood reddish brown or with vinaceous tinge, evenly colored. 



Giho (Shorea guiso). 



Wood yellowish, yellowish green, or golden brown, rarely reddish with 



greenish concentric bands 6- 



6. Wood yellowish, turning to golden yellow with age, fine textured; hard 



and heavy; specific gravity generally below 0.80.... Manggachapui group. 



Wood yellowish brown or occasionally reddish with a greenish tinge, 



variable in texture; hard to very hard, heavy to very heavy; specific 



gravity over 0.85 *akal *roup. 



THE NARIG GROUP 



The narig group is the product of the genus Vatica which is 

 represented in the Islands by five described species. The woods 

 of this genus are very much alike and differ only in their 

 minute features. 



Gross features. — Sapwood light yellowish, thick, very resin- 

 ous, exuding resin until thoroughly seasoned; heartwood light 

 yellow when first exposed, turning to reddish yellow with age. 

 Wood very fine textured and fairly straight grained, very hard, 

 and very heavy; specific gravity, about 1. 



Microscopic features. — Vessels very small (20 to 150 p. in 

 diameter), completely occluded with tyloses; tyloses with simple 

 pits. Tracheids and fiber tracheids absent. Libriform fibers 

 with distinct radial arrangement, often polygonal in transverse 

 section. Vertical parenchyma scanty, vasicentric and diffuse, 

 easily mistaken for pores. Idioblasts present. 



Remarks. — The woods of this group are seldom found in the 

 trade, owing to their scarcity, although Vatica species are 

 widely distributed throughout the Archipelago. Only one 

 species, Vatica mangacJiapoi Blanco, is of importance. 



