A Visit to Hong Kong
by P. G. Valder
School of Biological Sciences, University of Sydney
Reprinted with permission from The Rhododendron Journal of the Australian Rhododendron Society
After reading the descriptions by G. A. C. Herklots
of the rhododendrons of Hong Kong, I have long felt that they might well prove to be better suited to our conditions than most members of the genus. Also I have been hoping for some years to have the opportunity of both seeing them growing in their natural habitat and introducing them to cultivation in Australia.
The opportunity came at last during a brief stopover in Hong Kong in January of this year. I was most fortunate in having an introduction to Mr. Chan Shu Tong of the Department of Botany, University of Hong Kong, who, within moments of my having met him, had taken me to Victoria Peak. Here, on the precipitous slopes above the city, is the most easily accessible piece of the Chinese flora.
In thickets of dwarf bamboo, Gordonia axillaris, Raphiolepis indica , and various other plants were numerous specimens of two azaleas, Rhododendron simsii , and R. farrerae . The former is the brick-red azalea of the Indicum subseries, which is widely distributed in south-east Asia and which has played a large part in the breeding of many of the azaleas grown in our gardens. The latter is a deciduous member of the Schlippenbachii subseries and some plants were already bearing a few mauve flowers. The wild plants of these species were rarely more than a meter tall, usually much less.
Growing beside a path was a bush, about four meters tall, of R. championae , with bristly leaves and stems and purplish buds. If descriptions are any guide, this has the largest flowers of the species of the Stamineum series and they are pale-pink fading to white. Mr. Chan has not observed any plants of R. championae in Hong Kong to set seed so it must be propagated by cuttings.
Not far away was a plant of Camellia hongkongensis and numerous plants of Enkianthus quinqueflorus , already bearing masses of pale-pink, waxy bells hanging below clusters of pinkish young leaves.
In this part of the world flowering branches of E. quinqueflorus are associated with the Chinese New Year rather in the manner which holly is with Christmas in western countries. They were seen on sale in shops and markets both in Hong Kong and Macau, having been brought from the mainland, as had potted camellias and chrysanthemums in blooms and innumerable calamondins, cumquats, mandarins, and oranges, all with an unbelievable profusion of ripe fruits. Also on sale for the Chinese New Year were trees described as "red peach blossom," which appeared to me to be a richly-colored form of Prunus mume .
The next day Mr. Chan took me to Ma On Shan, a mountain in the New Territories. We went in a double-decker bus to the new Chinese University and from there crossed the bay to the foot of the mountain in a ferry. Here we were given a lift on a lorry belonging to the iron mining company which operates on Ma On Shan, this resulting in our making two-thirds of the ascent without any exertion at all. This was just as well, as it was a cold, miserable day with the mountains shrouded in mist and drizzle.
We continued the climb on foot through a low scrub of wet grass, Baeckia, Gordonia and Raphiolepis, and after a time came upon stunted trees of Pinus massoniana and the first plants of Rhododendron simsii and R. farrerae . Our goal, the saddle between two peaks, was soon reached and we were able to explore the steep, north facing slopes immediately below it. Here were numerous plants of R. simiarum and what I presumed to be R. hongkongense growing amongst the dwarf bamboo. Also conspicuous here were plants of Ardisia crispa in fruit.
The bushes of R. simiarum were compact, about 1.0-1.5 meters tall, and bore handsome, glossy foliage. Few bore flower buds or showed evidence of having bloomed the previous spring, so it is presumably shy-flowering. However coming as it does from a climate with mild winters and periods of heat and drought in summer, this member of the Arboreum series may well prove useful as a parent in the breeding of hybrids suited to Australian conditions.
R. hongkongense is a member of the Ovatum series and presumably is the plant previously recorded from this locality as R. ovatum . However the latter species was described from specimens collected on the island of Chusan by Fortune from plants with ovate leaves and light mauve flowers with darker spots. It also occurs on the mainland nearby but according to Sealy 2 , is replaced in Kwantung and Hong Kong by R. hongkongense , which is distinguished by the flower-bud scales being glabrous outside, the leaves more or less elliptic, the calyx lobes smaller, rounder and densely setulose on the margins, and the corollas white with violet spots. The plants on Ma On Shan bore a few flowers and appeared to be of this type. On young plants and on shoots arising from the bases of the older ones, however, the leaves were ovate with conspicuous hairs on the margins.
Time did not permit our continuing on to the slopes where another member of the Stamineum series, R. westlandii , is found. This name, together with a number of others, has been reduced to synonymy with R. moulmainense by Sleumer 3 . From a horticultural point of view, however, the form described as R. westlandii is distinct and has pink flowers.
All the Rhododendron species mentioned other than R. westlandii , have been introduced to cultivation in Australia and it is hoped that, before long, the remaining one will be introduced as well. Seedlings of Enkianthus quinqueflorus are also being raised, as also are some of the Hong Kong form of Gordonia axillaris , which in the wild is rarely taller than about 1.5 meters.
1. Herklots, G. A. C., The Rhododendron Year Book, 1949, Royal Horticultural Society, London, pp. 183186.
2. Sealy, J. R., Bot. Mag. n.s., 502.
3. Sleumer, H., Blumea, Supply, 4, p. 58, 1958.