safford: lignum nephriticum 507 



genus Pterocarpus. Dr. Moller made a careful examination of 

 the various woods hitherto supposed to be the true Ugnum 

 nephriticum mexicanum, among them specimens of the wood of 

 Eysenhardtia amorphoides, sent to him by C. A. Purpus, the 

 latter described as "das Kernholz von einen recht dicken Ast," 

 but with negative results (''keine Fluoreszenz)." On examin- 

 ing the heartwood of a Philippine species of Pterocarpus, how- 

 ever, he found that in water containing lime it yielded an infusion 

 having the characteristic sky-blue fluorescence of lignum nephriti- 

 cum mexicanum as described by early investigators. He there- 

 fore assumes that the mother-plant of lignum nephriticum 

 mexicanum, "sought in vain for 300 years by so many investi- 

 gators, is a Mexican species of Pterocarpus," in all probabil- 

 ity Pterocarpus amphymenium DC. (Arnphymenium pubescens 

 H.B.K., Pterocarpus pubescens Sprengel) ; and he refers a second 

 kind mentioned by Hernandez, endemic in Quauchinango, to 

 Pterocarpus orbiculatus DC.^^ 



There can be no doubt that the heartwood of some species of 

 Pterocarpus does yield a fluorescent infusion; but the "lignum 

 nephriticum mexicanum," or "coatl/' of Hernandez, the leaves 

 of which are described as "resembling those of Cicer arietinum 

 but smaller, " and which are also compared with the finely divided 

 leaves of the common wild rue, cannot possibly be identified with 

 any known Mexican species of Pterocarpus. The leaflets of the 

 species of Pterocarpus figured by Moller himself exceed 6 cm. in 

 length by 3.5 cm. in breadth. 



IDENTIFICATION OF LIGNUM NEPHRITICUM 



In connection with his work on the economic botany of Mexico 

 the writer has for years been seeking the source of lignum nephriti- 

 cum. Among other woods examined for the blue fluorescence 

 characterizing this wood were specimens of branches of Eysen- 

 hardtia polystachya, collected by the writer in 1907 in the vicinity 

 of Aguascalientes, the infusion of which gave no evidence of 

 fluorescence in ordinary sunlight. From this fact and from the 



11 Moller, Hans-Jacob. Lignum nephriticum. Berichte der Deutschen 

 Pharmaz. Gesellsch. 23: 88-154. 1913. 



