516 safford: lignum nephriticum 



the State of Oaxaca at elevations of 1500 to 1800 meters, especiallj^ on 

 the slopes of barrancas or canyons; and m northeastern Michoacan, 

 where the trees are large enough to yield valuable cabinet wood. A 

 specimen in the U. S. National Herbarium collected at the station of 

 La Junta, Michoacan, by Langlasse (no. 226) is described by the col- 

 lector as "arbre au tronc elance; bois, recherche pour ebenisterie, 

 prouduit une teinture bleue." The specimens in the Economic Her- 

 barium of the U. S. Department of Agriculture, including the wood with 

 fluorescent properties, described in the present paper, were collected 

 in north-central Tamaulipas, not far from the village of San Nicolas. 

 They are shown in figure 2. 



DENDROLOGICAL NOTES 



Microscopic sections of the wood of Eysenhardtia polystachi/a 

 were made at the writer's request, by Dr. Albert Mann, Plant 

 Morphologist of the Bureau of Plant Industry, and by Mr. 

 CD. Mell, Assistant Dendrologist of the Forest Service. Dr. 

 Mann found the heart wood to be extremely compact, heavily 

 Hgnified, and impregnated with a gum, or resinoid substance, 

 which did not break down in xylol. This gum is contained in 

 tracheae, which in cross sections appear like pores, either soli- 

 tary or in groups of two or three. Radial and tangential sections 

 show the tubes, with pitted walls, to be partly or entirely filled 

 wdth this gum, and they also show the medullary or pith rays, 

 which in the cross-sections are inconspicuous. The annular 

 lines of growth, however, are well marked in the cross sections. 



Specimens of Philippine Ugnum nephriticum (Pterocarpus 

 iyidicus) commercially known as narra, from Baggao, province 

 of Cagayan, Island of Luzon, were obtained by the writer from 

 the newly installed wood-collection in the U. S. National Museum. 

 This wood bears little resemblance to that of Eysenhardtia. In 

 the specimens obtained the color was a beautiful deep flesh tint 

 variegated with light red ; the grain coarse and somewhat twisted ; 

 and the annular lines of growth, as seen in the cross-section, ver}^ 

 distinct, with conspicuous large pores between them. Chips 

 of this wood in tap water yielded a yellow infusion of a lighter 

 shade than that of Eysenhardtia polystachya but reflecting a very 

 similar blue fluorescence. 



