i PREFACE.
In another place in Bootan (Pass of Rodoola, 12,000 feet), Mr. Griffith speaks of Rhododendrons as the only vegetation at
the summit, and in the descent he traversed a “ region of Rhododendrons.”
It is not our intention, nor is it required by the nature of this little treatise, to enumerate all the Rhododendrons that
are known in books -. suffice it to say, that (exclusive of some Azaleas of Linnaeus) thirty-two are distinguished by
De Candolle in the seventh volume of his Prodromus, published in 1839; and enough has been here stated to show that the
maximum of the species exists in Asia; for, commencing with Borneo and other Malayan islands in the tropics of the
southern hemisphere, and proceeding north, we find them recorded in the mountain regions of all the intervening countries
that have been botanically investigated, even to northern and extreme arctic Siberia. As we proceed westward into
Europe, they gradually disappear, one only inhabiting Sweden and Norway (22. Lapponicum), and that seems not to extend
to the western coasts.
In the vast continent of North America, the cool hilly grounds, with moisture, of the middle and southern states,
yield only 22. maximum (which, however, is found also in Canada), 22. macrophyUum, Don, confined to the west side of
the Rocky Mountains, 22. Catawbiense and 22. punctatum, which two have a very limited range. The anomalous
22. albiflorum, with white flowers and deciduous leaves, is only seen in the Rocky Mountains, about lat. 52°. As might
be expected, in the alpine and arctic regions the northern European kinds appear; for example, 22. Lapponicum has been
detected on the White Mountains, Massachusetts, on the summit of Mount Mary, Essex County, New York, at an elevation
of 5,400 feet on the Rocky Mountains, in Labrador, and along the coasts of the Polar Sea; while in Behring’s Straits, the
22. Kamschaticum again appears. No species grows in Mexico or near the coasts of Oregon or California, and none in
the isthmus of Panama. Throughout the whole of Africa1 and Australia, the genus is unknown; and it will be observed
that it only enters the southern hemisphere through the medium of the Indian Archipelago.
When it is borne in mind that, as above stated, Mr. Griffith, in an excursion to one mountain in Bootan, detected eight
species,2 and that the author of the present work, during a very limited sojourn in Sikkim, and with little means of prosecuting
extensive researches, owing to the nature of the country and the hostile feeling entertained towards the English by the
Rajah, yet collected and described eleven species, of which nine were new, it may, I think, be fairly conceded that if the
maximum of Rhododendrons be in Asia, their head-quarters are on the lofty ranges of the Eastern Himalaya, where the
mild and moist atmosphere is eminently suited to their habit.—Ed.
1 Boissier, indeed, in his Voyage Botanique en Espagne, says of the 22. Ponticum.:—“ Hab. verosimiliter in Atlanta,”—but I know not
upon what authority.
2 How far these species may accord with those of Sikkim, or whether any will do so, cannot be determined, until the Hon. the E. I. C.
shall be pleased to nnlock the treasures contributed by Mr. Griffith to the Herbarium stores in the possession of the Company; and there is
now happily a prospect of this long-wished-for event taking place. The few Rhododendrons that have been edited by Dr. Wight we know to
be very different and of peculiar interest.
TH E
RHODODENDRONS
OF
S IK K IM-H IMA L AYA.
TT has been well remarked by the illustrious Wallich, (the Father of Nepalese Botany,) that in Nepal the genus
Rhododendron olaims the highest rank amongst the plants of that rich kingdom. From the proximity of Sikkim to
Nepal, a similarity in the botanical features of these countries might be expected; and also that the difference should
rather exist in individual species than in the genera or higher groups. The outline of the two countries is very similar,
their latitude the same, so is their geology, and the difference in climate is slight, and only evident in the increased
humidity of the eastern region.
Rhododendrons are distributed in Sikkim as they are in Nepal, crowning those sub-Himalayan hills which attain 7,000
feet of elevation, and at a still greater altitude increasing in number of species and individuals: some species being replaced
by others which have no greater, perhaps less, apparent adaptation for resisting vicissitudes of climate, and yet accompanying
several of the more local kinds throughout the elevations they severally attain.
I. As is frequently the case with large genera, one or more species, distinguished by peculiarity of distribution,
often present some anomalies in botanical or other characters, whether in the unusual habit, mode of growth, or
singular outline, colour, or more important feature. So it is with the Sikkim Rhododendrons, R. Dalhousice, the only one
found so low as at 7,000 feet, and thence upwards for 8,000 feet more, differs from all its congeners of Northern India in
its epiphytal mode of growth,1 its sweet-scented flowers, slender habit, whorled branches, and in the length of time
during which it continues in bloom. It is much the largest-flowered species with which I am acquainted, and has more
membranous leaves than any of the others. With all these striking anomalies, it does not, however, present one
character of calyx, corolla, stamens, or pistil, entitling it to separation from the genus. In possessing a large foliaceous
1 In Sikkim, Vaccinium offers a parallel case. The V. serpens (?), an epiphyte on very large trees, inhabits a much lower level ana
ranges through many more feet in elevation than any of its congeners. [In Borneo it will be remembered that Mr. Low discovered epiphytal
Rhododendrons; and Mr. William Lobb, several in Java. Ed.]