Note on the Origin of Cassia Lignea. *
(* From the Journal of the Linnean Society, December 18, 1882.)
By W. T. THISELTON DYER, M.A., F.R.S.,
Assistant Director, Royal Gardens, Kew.
The spice now known in pharmaceutical literature under the name of Cassia lignea has, from time immemorial, been an article of trade from South China. Flückiger and Hanbury are indeed of opinion that it was the cinnamon of the ancients, what now bears the name being peculiar to Ceylon and unnoticed as a product of the island till the thirteenth century. ("Pharmacographia," pp. 520, 521.) Cinnamon and cassia are, however, enumerated amongst the products of the East from the earliest periods; and the former was known to the Arabians and Persians as Darchini (dar, wood or bark, and chini, Chinese). It seems in ancient times to have been carried by Chinese traders to the Malabar coast, where it passed into the commerce of the Red Sea. In this way the statements of Dioscorides, Ptolemy, and others, are accounted for, who speak of cinnamon as a product of Arabia and Eastern Africa, countries in which there is no reason to suppose it ever grew. At the present day it is still an important item in Chinese commerce. I find, from the Statistical Returns of the Chinese Imperial Customs (for copies of which Kew is indebted to Sir Robert Hart), that the export from China for the last two years stands as follows: ("Returns of Trade at the Treaty Ports for the year 1881," p. 10.)
|1 picul = 133 ⅓ lbs.; 1 Haikwan tael = 5s. 6 ½ d.|
With regard to the botanical source of Cassia lignea, it is remarkable, considering its ancient history and its present importance in trade, that up to the present time nothing certain has been ascertained. Flückiger and Hanbury remark:—"Although it is customary to refer it without hesitation to a tree named Cinnamomum Cassia, we find no warrant for such reference; no competent observer has visited and described the cassia-yielding districts of China proper, and brought therefrom the specimens requisite for ascertaining the botanical origin of the bark." ("Pharmacographia" p. 528.)
Bentley and Trimen also remark, in their "Medicinal Plants," (Vol. iii., sub tab. 223.) "Though it is probable that this species (Cinnamomum Cassia) affords Chinese cassia, the fact has never been proved."
In the face of the uncertainty felt by these authorities, it appeared to be desirable to have the point, if possible, cleared up. The attention of the Colonial Office was accordingly drawn to the matter, November 18, 1881; and it was suggested that Mr. Charles Ford, Superintendent of the Botanical and Afforestation Department, Hong Kong, might be allowed, with the consent of his Government, to proceed to the cassia plantations on the West River for the purpose of reporting on the cultivation and collection of Cassia lignea, as well as of bringing back for distribution from the Hong Kong Botanic Garden living and dried botanical specimens of the authentic plant. Lord Kimberley was so good as to approve of the proposal; and in the month of May last Mr. Ford accordingly started for the cassia districts of the West River, the Sai Kong. He completely succeeded in the object of the expedition, and described his journey and its results in a Report to the Hong Kong Government, August 9. This report has been printed as a Government Notification (No. 339); but as in that form its circulation will necessarily be very limited, I think the facts deserve the wider circulation which will be afforded by the Society's Journal.
Mr. Ford's journey was timed so that he might be in the districts at the season when the trees were flowering. This enabled him to obtain authentic specimens for their botanical identification, and also to witness the operation of obtaining and preparing the bark.
Mr. Ford gives the following account of the geographical position and extent of the cassia districts:
"There are three chief districts where the Cassia is cultivated, viz.:—Taiwu, in lat. 23° 34' N., and long. 110° 18' E. in the Kwangi province; Lukpo, in lat. 23° 6' N., and long. 112° 24' E.; and Loting, in lat. 22° 52' N., and long. 111° 8' E., both in the Kwangtung province. These are the market towns of the district; but the cassia is cultivated over a large area of country stretching to considerable distances from the towns, the extent of which could not be ascertained, Owing to the unreliable accounts given by the different people questioned, who either had very vague notions of area, or were disinclined, as they usually are, to give information to foreigners.
"Taiwu is about four or five miles from the West River, and is reached by a pleasant walk leading over a plain; but the nearest cassia plantations are situated twenty-five or thirty miles further in a southern or southwesterly direction, to which there is no communication by river. Taiwu is about one hundred and eighty miles west of Canton. The Taiwu people said that the area of cultivation was not increasing. ("Near the town of Taiwu, according to Mr. Moss ('Narrative of an Exploration of the West River,' 1870), the best cassia bark is produced" (Bretschneider, "Early European Researches into the Flora of China," p. 13).)
"The next most important, if not the most important (or at least tending in that direction) district is the Loting one, commencing at about eight or ten miles distant from the city of Loting. After leaving the West River, about eighty miles of the Loting River—the Nam Kong—has to be traversed before reaching the city, and from there the distance to the plantations has to be accomplished overland. One of the largest cultivators said that in this district there were about 1,000,000 maus (about 52,600 English acres) under cultivation, and that the area was greatly extending every year. The cultivation of cassia has been carried on here for only about twenty-five years, i.e., since the Tai-Ping rebellion, at which time, for the preservation of the plants and protection of them from destruction by the rebels, they were transferred from a district further south, at which it is reported the cultivation of cassia was abandoned when it was commenced at Loting
"The next district is that of Lukpo, which is much less important than the other two. The city of Lukpo is situated on the northern bank of the West River; and the plantations are situated at about fifteen miles between the nearest one and the city.
"In addition to these places there are several small localities near the West River at intermediate places, where small patches of cassia are grown; and as the quantities of bark obtained are too small to send to market towns, it is brought off by small boats and sold to larger boats which carry produce down the river.
"About six miles southwest of the small town of To Shing, which is situated on the southern bank of the river, about twenty-five miles above the confluence of the Loting and West rivers, there are some plantations, from which, however, no bark has been obtained for two years and no new plantations made for ten, because the low prices which can now be obtained for the bark do not leave any profit to the producer. This was the only instance which came to my knowledge of the decrease of the trade in the cassia production, although it is said that the Java cassia trade, in consequence of the lower prices at which the cassia can there be produced, is cutting out and crippling the China trade."
From each of the districts of Taiwu, Lukpo and Loting, Mr. Ford obtained and sent to Kew copious and excellent specimens. These have been examined by my colleague, Professor Oliver, who informs me that they certainly all belong to the same species, and that this is undoubtedly Cinnamomum Cassia, Blume. Mr. Ford took great pains to ascertain if this was the exclusive source of Cassia lignea. He reports:
"This is the only tree from which cassia bark, 'buds,' or leaves of commerce in China, so far as could be ascertained from personal inspection and reports, are obtained. All the trees seen in the districts of Taiwu, Loting and Lukpo, and intermediate localities where cassia was grown in smaller quantities, were of this species, nor were there, apparently, distinct varieties of the species in cultivation. The cultivators and other natives were much interrogated as to whether they knew or had heard of any other tree which yielded the products under notice, and the invariable reply was that there was no other kind. There is, therefore, I think, no doubt but writers who have named other kinds as cassia-yielding trees of China have been mistaken or misinformed on the subject. One writer alludes to a tree in terms which partly corresponds to the description of Machilus velutina, Champ., another tree belonging to Lauraceae, and indigenous to South China. It is quite possible that this tree may have been supposed by a casual observer to yield cassia bark, because it is sometimes grown in plantations intermixed with those of Cinnamomum Cassia. The trees are reared planted, and treated in precisely the same manner as the cassia trees; but the bark is required for a very different use, viz., to supply a glutinous extract which is used to stick together powdered cassia bark and sandal wood (Santalum album) to form the joss-sticks used for incense. Cinnamomum Burmanni, Bl., which it has been supposed may probably yield 'in part the cassia bark of the Canton market,' does not, I feel sure, supply cassia bark to any extent. I did not see it anywhere cultivated; nor was it seen growing wild in any but small quantities, and these wild trees bore no signs of having been cut as had the cassia trees; many natives were asked if it was ever used; but, with one exception, all denied that it afforded any cassia bark. The one exception was an old woman, who was cultivating a field of Indian corn close to a few small trees of Cinnamomum Burmanni, and who said that its bark was sometimes, but rarely, used to adulterate the true cassia bark."
Mr. Ford on his return journey paid a visit to the well-known Chinese botanist, Dr. Hance, H.M. Vice-Consul at Whampoa, who identified the specimens of the cassia lignea tree collected by Mr. Ford as belonging to Cinnamomum Cassia. There is, in fact, in the Kew Herbarium a specimen of the same species collected by Dr. Hance in 1876; but I have searched in vain to see if Dr. Hance has published anything about it, and the specimen bears no note that it is the source of Cassia Lignea. This specimen is the material upon which the plate given by Bentley and Trimen is based, and represents no doubt the true plant.
Cinnamomum Cassia was first described by Blume, in 1825. ("Blidragen Fl. Nederl. Indië," ii., p. 570.) The species was apparently founded on cultivated specimens from Java, where Blume states it was "ex China introductum."
The Kew Herbarium possesses a cultivated Java specimen contributed by the Leyden Herbarium. This is no doubt an authentic type of the plant described by Blume; and Professor Oliver finds that it agrees precisely with the plant collected by Mr. Ford on the West River. It may be, therefore, considered finally settled on the one hand, that the Chinese cassia lignea plant is really the Cinnamomum Cassia, Blume, and on the other hand, that the plant cultivated in Java is identical with that now known to be the source of the spice in China.
It is remarkable that though the cultivation of the cassia lignea tree has apparently been carried on in Southern China from time immemorial, it does not appear to be indigenous there. (The earliest printed notice in works professing to give botanical information about China appears to be in Martini's "Atlas Sinensis" (1655). See Bretschneider's "Early European Researches into the Flora of China," p. 13.) In Cochin-China, however, there appears to be some probability of its being really wild. Cinnamomum Cassia is, botanically, very closely allied to C. obtusifolium, Nees, one of the species from which a similar product is obtained on the Khasia hills.
It only remains to give Mr. Ford's account of the mode of collecting and preparing the bark. He obtained and sent to this country a set of the implements, which are deposited in the Kew Museum.
"Bark.—When the trees are about six years old, the first cut of bark is obtained. The season for barking commences in March and continues until the end of May, after which the natives say the bark loses its aroma, and is therefore not removed from the trees. The branches, which are about an inch thick, being cut to within a few inches of the ground, are carried to houses or sheds in the vicinity of the plantations. All the small twigs and leaves being cleared off, a large-bladed knife, with the cutting-edge something like the end of a budding knife, is used to make two longitudinal slits and three or four incisions, at sixteen inches apart, round the circumference through the bark; the bark is then loosened by passing underneath it a kind of slightly curved-horn knife with the two edges slightly sharpened. Pieces of bark sixteen inches long and half the circumference are thus obtained.
"The bark, after its removal and while it is still moist with sap, is then laid with the concave side downwards, and a small plane passed over it, and the epidermis removed. After this operation the bark is left to dry for about twenty-four hours, and then tied up in bundles about eighteen inches in diameter, and sent into the merchants' houses in the market towns.
"Leaves.—The leaves which are cleared from the branches that are barked are carefully preserved and dried, and afford by distillation Cassia oil. A large number of leaves are sent to Canton, where I was told the operation of distilling is performed.
"Twigs.—These are removed from the cut branches at the same time as when the leaves are obtained. They are a marketable commodity for native uses.
"Buds.—Cassia-buds are the immature fruits. They are gathered when about one-eighth grown. Buds, and the seeds which are annually required for sowing, are obtained from the trees ten years and upwards of age that are left standing at about fifty and a hundred feet apart amongst the trees which are cut down every six years for their bark. These seed-bearing trees are not cut unless there is a demand for the very thick bark on their trunks, when some of the trees which can be conveniently spared are sacrificed.—Phar. Jour. and Trans., January 20, 1883.