2 SEEDS AND PLANTS IMPORTED. 



A true sweet corn (No. 53217) from 7,000 feet altitude may 

 indicate to the plant breeder the origin of the sweet corns of our 

 gardens and ma}^ be useful in producing a variety for our own 

 warmer regions. 



Two promising new species of Rubus of good quality {R. roseus, 

 No. 53218, and R. adenotrichos, No. 53219) ; a beautiful Andean 

 barberry, Berheris quinduensis (No. 53177) ; the hard-shelled pas- 

 sion fruit, Passiflora Tnaliformis (No. 53180), of promise for Cali- 

 fornia: the quiqui, Osteomeles ohtiisifolm (No. 53485), a new tropical 

 hawthornlike shrub which has been used as a stock for the apple in 

 Ecuador; and the higacho, ('arica chrysopetala (No. 53754), which 

 resembles the mountain papaj^a, Carica candaviarcensis ^ but is spe- 

 cifically distinct and may contribute material for the breeding prob- 

 lem of producing a small sweet-fruited papaya which can be shipped 

 like a tomato or an avocado; are some of the plants which Mr. 

 Popenoe found and introduced. 



While Mr. Popenoe was carrying out a difficult piece of explora- 

 tion work in Ecuador, Joseph F. Rock, our newly appointed agri- 

 cultural exjDlorer, was searching for the source of chaulmoogra oil 

 in Siam and Burma. This oil, or rather the ethyl esters of its con- 

 stituent chaulmoogric acid, which were originally discovered and 

 described by Dr. Frederick B. Power, has come into great promi- 

 nence as a cure for leprosy through the researches of Doctor Dean 

 and his collaborators in Honolulu. The source of the oil, which 

 comes into commerce through Burma, was quite obscure 'when 

 Mr. Rock first took up the studj' of these trees and was commissioned 

 as an agricultural explorer to investigate the whole subject; no 

 photographs had ever been made of them. He spent several months 

 in the jungles of Siam and Burma and went through experiences 

 quite as thrilling and dangerous as any to which explorers in tropical 

 countries are liable, including a unique one with a man-eating tiger. 

 In the course of his explorations (fig. 1) he traversed the northern 

 mountainous part of Siam, bordering on Burma, which had not previ- 

 ously been visited by botanists. Not only has he in large measure 

 solved the problem of the source of chaulmoogra oil, but he obtained 

 seeds of the true chaulmoogra tr-ee {Taraktogenos kurzil. No. 53844) 

 and of the more important allied trees, including Hydnocarpus 

 wightiana (No. 52859) and also H. castanea and H. anthelmintJtica 

 (recorded in Inventory No. 66 under Nos. 52514 and 52465), as well 

 as the false chaulmoogra tree, Gynocardla odorata (No. 53121), 

 which for years was erroneously supposed to be the source of chaul- 

 moogra oil. Though Mr. Rock's main quest was the chaulmoogra 

 trees — which quest he has described in Department Bulletin No. 1057, 

 entitled " The Chaulmoogra Tree and Some Related Species," and in 

 the National Geographic Magazine for March, 1922 — he nevertheless 

 obtained seeds of other trees and plants of great interest to those 

 whose climatic surroundings will permit their cultivation. 



The success of the bor {Ziziphus mauritlana) on the calcareous 

 soils of southern Florida makes those who are already interested in 

 this new fruit anxious to compare with the plants sent in from 

 Mauritius Rock's variety (No. 52858) from the upper Chindwin 

 River of Burma. 



