﻿54 SEEDS AND PLANTS IMPORTED. 



44291 to 44294^-Continued. 



44292. Brassica pekinensis (Lour.) Gagn. Brassicacese. Pai ts'ai, 

 " (No. 2376a. Ansuhs : en, Chihli Province, China, January 18, 1917.) 



Pai ts'ai, meaning ' white vegetable.' A heavy quality of white winter 

 pai ts'ai, much in demand and generally disposed of by the growers to 

 private customers before the end of December. Needs a rich soil and 

 no lack of moisture to become tender and sweet." {Meyer.) 



44293. RAr-HANus sativus L. Brassicacese. Radish. 

 "(No. 2377a. Ansuhsien, Chihli Province, China, January 18, 1917.) 



Teng lung hung lo po, meaning ' lantern red root,' referring to the re- 

 semblance of the root to a Chinese or Japanese flat lantern. A large, flat 

 red, winter radish, said to grow as heavy as 5 catties apiece. Needs 

 rich, well-drained soil to do well. Sow out in summer, not in spring." 

 (Meyer.) 



44294. Allium fistulosum L. Liliacese. Leek. 

 "(No. 2378a. Ansuhsien, Chihli Province, China, January 18, 1917.) 



Ta Vou st'ung, meaning 'large-headed leek.' A peculiar variety ol 

 Chinese winter leek of very short growth, looking almost like a slender 

 onion. Said to be of very good flavor ; possesses also good shipping and 

 keeping qualities. Does best in light, rich, moisture-retaining soil." 

 (Meyer.) 



44295. Pavetta zimmermanniana Valet. Kubiacese. 



From Buitenzorg, Java. Presented by Dr. J. C. Koningsbergei% director, 

 Botanic Gardens. Received March 19, 1917. 



A small rubiaceous tree or shrub, with opposite, nearly elliptic leaves and! 

 clusters of small slender-tubed white flowers. 



" The remarkable researches of Zimmerman and Faber detailed In the Jahr- 

 biicher fur Wissenschaftliche Botanik, vol. 51, p. 285, 1912, and vol. 54, p. 24B, 

 1914, make this species of unusual interest. Faber has proved that the leaves 

 of this and of several other species of Pavetta, Psychotria, and possibly other 

 genera of the Rubiacese contain colonies of a nonmotile, nitrogen-fixing bac- 

 terium which he names My co-bacterium rubiacearum. The bacteria of this 

 species almost invariably inhabit the micropyle of the young seed and when 

 the seed germinates grow through certain stomata of the very young leaves 

 and into the intracellular spaces formed in the leaf tissues around these 

 stomata. Cavities are formed through the growth of the epidermal cells which 

 later close entirely and make bacterial nodules which are deeply embedded in 

 the leaf tissues. A single leaf may have several dozen of these symbiotic bac- 

 terial nodules. 



" Faber was able, by treating the seeds with hot water and a sublimate solu- 

 tion, to kill the inhabiting myco-bacteria and, later, to infect part of the seed- 

 lings grown from these seeds with pure cultures of the bacterium. The arti- 

 ficially infected seedlings grown in soil free from combined nitrogen grew well 

 and remained healthy for four months, whereas those not so infected turned 

 yellowish white and died in three or four weeks. The plants from unsterilized 

 seeds produced leaves bearing many more bacterial nodules than did those 

 from sterilized seeds which were later artificially inoculated. In view of the 

 fact that these rubiaceous plants with bacterial nodule-bearing leaves occur 

 in many parts of the Tropics and that in India, at least, the value of their 

 leaves for manure has long been recognized, and considering the value of nitro- 



