April 



1883.] 



THE TROPICAL AGRICULTURIST. 



817 



CINCHONA LEDGERIANA ; A HYBRID ? 



By Otto Kdntze, Ph. D. 



(From the "Journal of Botany Britinh and Forevjn" 



for January 1S83, parjes 5 to H.) 



Dr. Henry Trimeu published in this journal for 

 1881 (pp. 321-32.')) a paper entitled " Cinchona Ledger- 

 iana, a Distinct Species," wherein he maintains that 

 C. Ledgeriaiia is not a variety of C. Calisaya, as Mr. 

 .1. E. Howard had supposed. He cites the following 

 marks in support of his position : — (1) The leaves of 

 C. Ledgeriana have always the broadest jiart at or 

 about the middle. (2) The flowers approach those of 

 C. Mii'rantha in their drooping habit, small size, short 

 inflated tube, white colour, and also (3) by their buds, 

 which are not at all or very slightly widened at the 

 end, and never abruptly enlarged there, as they are in 

 C. Calisaya. 'I his last character is new to me. 



C. Calisaya and C. Micrantha are the only species 

 mentioned as nearly allied to C. Ledgeriana. I have 

 described indeed 0. ledgeriana as a hybrid of these 

 two species in my monograph of cinchona* wherein I 

 acknowledge only four species : — Weddelliana=C. 

 Calisaya pro parte ; C. Pavoniana=C. Micrantha p. p. ; 

 C. Howardiana=- C. succirubra p. p.; and C. Pahiidiana 

 How. All other cinchonas I regard as synonyms or 

 hybrids of those fouj- species. The hybridization of 

 cinchonas has been proved (1) by some direct artiticial 

 production of several hybrids, (2) by the fact that tlie 

 seeds of marked trees produced plants with the mixed 

 characteis of another species. There cannot be any 

 doubt as to the copious hybridization of cinchonas ; 

 and it is well known that the hyljrids in the cinchona 

 plantations have plenty of good fertile seeds ; only C. 

 ledgeriana shows an exception, and its more or less 

 great sterility has been often noticed. 



Cinchona Ledgeriana originated spontaneously in the 

 tJovernment plantations of Mungpo in Sikkim, as pul)- 

 lished by me in my monograph of cinchona. Dr. 

 Trimen did not know this fact, and it would seem that 

 he has not read my monograph ; for he writes 

 (p. 322) : — " I made inquiries of Mr. Moens, wlio assured 

 me that he never- saw anything like l#dgeriana to 

 come from seed of a calisaya. I understand that Mr. 

 Gammie has the same experience." During my visit 

 to Java I never obsen-ed spontaneous C. Ledgeriana, 

 but in Mungpo-SikkuTi Mr. Ciammie and the late 

 Mr. Biermann assured me that " C. Ledgeriana had 

 originated spontaneously there in the calisaya field." 

 Besides Dr. Trimen supports this statement, saying 

 "in our own plantations in Sikkim, after years of 

 neglect as one of the troublesome and hopelessly 

 varialjle forms of (_'. calisaya, the plant (C. Ledgeriana) 

 is now the object of careful cultivation." Dr. Trimen 

 is therefore in error to write that " all existing plants 

 in the East are descendants of seeds collected in 

 Bolvia, in .June 186.5." 



But the testimony of the cinchona cultivators — 

 valuable as it mo.y be — is not necessary, for we know 

 a fact that proves the hybrid origin of C. ledgeriana 

 in Mungpo : the imported cinclionas in Mungpo are 

 trees, witli the exception of C calisaya, and all descend- 

 ants of C. calisaya are shrubs, pure calisaya are 

 small shrubs, and the hybridized calisaya are very 

 large shrubs, because the other hybridizing cinchonas 

 are only trees. C. Ledgeriana of Mungpo is also a 

 large shrub : it became only more tree-like by the 

 art of the cultivators, who prefer trees for bark 

 collecting. When I visited Mungpo, C. Ledgeriana 

 was mostly not yet treelike. In contrast to this 

 shrubby Ledgeriana of Mungpo the descendants of 

 Bolivian Ledgeriana in .Java and Southern India, per- 

 haps also ui private Sikkun plantations, are veritable 



* ' Cinchona, Arten, Hybrideu und Oultur der chiniu- 

 baume.' Leipzig, 1878; Verlag vou Haessel. 



trees. I do not know if there has been imported 

 Bolivian ledgeriana into the Mungpo Government plant- 

 ations after 1875; but until that date no Bolivian 

 ledgeriana existed there. 



The Mungpo ledgeriana shows another individual 

 mark, by which I can easily distinguish it from 

 Bolivian ledgeriana : the former has very divaricate 

 panicles with slender ramification, the Bolivian des- 

 cendants have a more dense panicle with thicker or 

 shorter branches. The C. micrantlia of Mungpo has 

 accidentally such slender divaricate panicles, and all 

 its hybrids at Mungpo, as well as C. ledgeriana show 

 that individual mark. The Mungpo calisaya field is 

 of very great extension, and it is the same plan on 

 which the former intendant of that plantation Mr 

 C. B. Clarke, sowed the calisaya. Mr. Clarke said in 

 JNovember lS/;>, to me, "we sowed calisaya and got 

 other plants," and among these other plants were 

 many shrubs of C. ledgeriana. 



I am anxious to correct the erroneous point of Dr 

 Trimen's publication, because Dr. A. Garcket has briefly 

 quoted the paper of Dr. Trimen against ray deduction 

 of tlie liybnd origin of C. ledgeriana ; he says also — 

 "Messrs. Moens and Trimen prove that C. ledgeriana 

 bears fruits like all other cinclionas, and they consider 

 it therefore as a distinct species." As all other arti- 

 ficial and spontaneous cinchona hybrids ripen good 

 seeds plentifully, the fertility only would be no proof 

 for the establishment of a species ; besides, the fert- 

 lity of C. ledgeriana is neither existing nor confirmed 

 by Dr. Trimen in that manner. 



Cinchona ledgeriana is the only cinchona that suffers 

 from sterility, and only ripens more fruits if it .rets 

 fertilized and hybridized by other cinchonas • that 

 happens often, and therefore the descendants of ledger 

 lana are mostly degenerated, and the to-called ledger- 

 iana bark of Java contains often very little quinine 

 (till only 0-8 per cent !). Dr. Trimen says that " the 

 seed ings [of C. ledgeriana] since Mr. Gammie uporooted 

 nearly all the neighbouring trees come remarkably 

 true, whereas before that was done the sporting was 

 so great that Dr. King would not propagate by seed at 

 all." No cinchona species shows a similar degeneration 

 as C. ledgeriana if growing between other cinchonas- even 

 the calisaya field of Mungpo shows yet a greater part of 

 true C. calisaya. Dr. Trimen says nothingaboutthe great 

 fertility of C. ledgeriana, as Dr. tJarcke supposes but 

 he gives an illustration of partly abortive fruits I 

 may refer to some other notes on the fertility of C 

 ledgeriana : Ledger wrote to Howard,: on the discovery 

 of C. ledgeriana m Bolivia, "he then told me the 

 best bark trees had not produced ripe seeds for four 

 years," whereof frost cannot be the cause, for 9II other 

 cinchonas there around ripened good seeds. In the 

 '■ Berigte nopens de Gouvernements Kiua Ondernem 

 ing " (2 Kwartaal, 1874, No. l!l) we read, C ledKer- 

 lanas give few seeds, and deceive us ; the best trees 

 were flowering to death. lu the 3rd Kwartaal 1875 

 from C. ledgeriana only fifty trees ripen sometimes a 

 few fruits. In the 4th Kwartaal, 1877: the seeds of 

 C. ledgeriana have failed. \'isiting the Java and 

 Mungfo plantations I observed also the poor fertility 

 of C. ledgeriana. ^ 



As all other cinchona hybrids are always extremely 

 fertile, I suppose C. ledgeriana must be an irregular 

 hybrid-irregular, because the se\-eral qualities of 

 the two parent species are not well combined as in 

 the regular hybrids of cinchona. For instance, C oflicin 

 ahs Hooker is the regular hybrid of C. calisaya and 

 C. micrantha, whilst C. ledgeriana is the irregular 

 hybrid of these two species. Both hybrids have the 

 broadest part of the leave s at or about the middle, 



■icl ,' Handworterbuch der Pharmakognosie von Wittsteiu ' 

 ioo2, p. lol. ' 



t Howard, "the Quinologj- of the East Indies ii iii 



p. it). ' ' '■> 



