400 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1950 



1741) . The so-called drug "Lichen quercinus virdes" consisted mostly 

 of Evernia prunastri, E. fwrfuracea^ and Parmelia physodes Ach., 

 (19). The doctrine reached the height of absurdity in the extrava- 

 gant value set on a lichen found growing on human skulls, "Mucus 

 cranii humani." This skull lichen {Parmelia or Physcia?) fetched 

 its weight in gold as a cure for epilepsy. 



Luykeu, in his "Historia Lichenum in Genere," Gottingen, 1809, 

 gives a long list of medicinal "Lichenes, quorum usus obsoletus est." 

 Plitt (13) recommended more emphasis on the study of lichenology to 

 pharmacognosists, venturing the opinion that the medical virtues of 

 bark drugs may be affected by the lichens growing on them. Fee dealt 

 earlier on this subject in a beautifully illustrated treatise (7). 



Iceland Moss was recognized by Linnaeus as a medicinally valuable 

 plant. It was used in chronic affections as an emollient and tonic, and 

 it would indeed have been a "Divine gift to man" had it lived up to all 

 its prescriptions. With the exception of this lichen, all have been 

 replaced by more effective modern drugs so far as medicinial use is 

 concerned. Tavares (in correspondence) reports that the soredia of 

 Usnea species is apjDlied as a medicine today in country districts of 

 Portugal. 



The use of lichen "leaves" as an insecticide, narcotic, and in magic 

 concoctions under the name of "natema" by the Jivaro Indians has 

 been reported by various travelers. It has now been verified that the 

 "leaves" in question are those of several well-known phanerogams long 

 used for these properties. There are no authentic reports in the liter- 

 ature of lichens being utilized by natives of South America. Among 

 the collections of the late Dr. O. F. Cook were found two packets of 

 lichens purchased by him in the Indian market of Sicnani, Peru. One 

 was annotated: "Intisuncja, mealy beard of the sun, grows on the 

 ground in high summits near the glaciers ; taken as tea for coughs, etc.'- 

 The other was "from the same places" but named "Pachacuti, a medi- 

 cine for fever." Both were Roccellaceae. 



Physiology. — The physiological action of the cetraric acid of Ice- 

 land moss has been studied by Kobert (13) . It has no poisonous effect 

 either when injected into the blood or when taken into the stomach of 

 small animals. Small doses induce peristaltic movements in the in- 

 testines. Large doses may injure an animal, but if given as free cetra- 

 ric acid it passes through the stomach unchanged to become slowly 

 and completely dissolved in the intestine. The mucous membrane of 

 the intestine of animals that had been treated with an overdose was 

 found to be richer in blood, so that Kobert assumed that cetraric acid 

 would be useful in assisting digestion. There is also the possibility 

 that the lichen acid inflamed the sensitive mucous membrane. By 

 mtans of acetone, c?-usnic, evernic, and obtusatic acids have been 



