Riddle Of A Missing Species Solved
John Patrick, Richmond, California
The author, having taken a particular interest in those Rhododendrons native to the outlying islands of Asia proper, wrote the University of Hong Kong inquiring into the possibilities of collecting seed in the wild and more specifically to investigate the possibility of any remaining vestiges of the described, but unavailable species, R. hongkongense.
My letter was answered by Dr. R. C. Stephen, Acting Head of the Botany Department, Hong Kong University. His letter indicated that from his investigations into the herbarium material at the University that the species was not known in Hong Kong.
Arriving in Hong Kong on December 15, 1968, I immediately got in touch with Dr. Stephen who kindly arranged a meeting despite a very heavy schedule. After discussing the aims of my project, with which he was in hearty agreement, he arranged a visit to the Hong Kong Government Herbarium to see what could be uncovered there.
After looking at the herbarium collection, which incidentally, contained a number of specimens from the E. H. Wilson 1900-1901 and 1907-1909 expeditions, I was greeted by Mr. Tang, the Director.
After knowing exactly what it was that I wanted, he proceeded to go through his library to see what additional information could be found. This cleared up the mystery. R. hongkongense had not become extinct through the tremendous building boom as had been previously suspected. Instead it had been lost in the literature.
This fragrant Rhododendron of the Ovatum Series, according to "Index Kewensis Supplementum VIII (1926-1930) had been renamed Azalea myrtifolia, this after Azalea myrtifolia had been previously described as a synonym for R. ovatum in "Index Kewensis" First Edition 1895, page 256 Tomus I. This accounted for the specimens labeled "R. myrtifolia" in the Hong Kong Herbarium collection. Now all that remained was to actually see the species in the wild to verify that it did indeed exist.
In the meantime, Dr. Stephen arranged that the University plant collector, Mr. Chen would accompany me on a collecting trip. Mr. Tang also arranged to have the Herbarium plant collector Mr. Lau accompany me, making a group of three.
Two days later, I was met at my hotel by Mr. Chen and Mr. Lau. Leaving the hotel at 9:00 A.M. we took a taxi to the Kowloon Vehicular Ferry to catch a bus going to the New Territories. This is Bus #19A SHEUNG SHU. After about a half hour, we arrived at a spot along the Ocean called Hotung Lau. From here we took a small motor launch across the Bay to Ma On Peninsula, about a 20 minute trip. We arrived on the other side at about 10:30 A.M. and started walking up a road past an iron mine toward Ma On Shan. Past the mine the going gets rough as we turned off the road and started to climb the mountain. After several most welcome stops to botanize the lower levels, we finally arrived at the main summit ridge about 1:00 P.M.
We had climbed up the South slope which bears the brunt of any tropical storms and is constantly scorched by the tropical sun. Some small plants of the azalea R. farrerae occur sparingly on this South slope and they were just coming into flower. Seeing that there were several seed capsules remaining from the previous season some seed was collected. Arriving at the top of the summit ridge it was observed that those plants of R. farrerae that had some protection from the wind and sun were in much better condition although not blooming yet. More seed was collected from these plants which are at a higher elevation.
Plants of R. farrerae are about ½ meter tall and produce single flowers from axillary buds. Flowers are five petaled, lavender with a red blotch. The flower is about 3 cm in diameter. Plants were growing in extremely poor soil as were all plants of all species growing in this area.
Just West of the 1200 M. ridge summit, over the brow of the hill to the North, we saw our first R. hongkongense. Indeed, it was not extinct, but growing in fairly large numbers and quite happily!
R. hongkongense is about 1½ M. tall and rather leggy. Tops of the plants are curved, somewhat sparse mounds of new growth covered with axillary flower buds, up to three per terminal. Leaves are about 3 cm long and glabrous. Leaf pedicels and main under leaf midrib are red. Small, un-budded seedlings of indeterminate age were observed to be quite hairy as is short adventitious growth emanating from the base of some plants. R. hongkongense is said to bloom in March. Not enough seed was collected for general distribution.
Continuing in an Easterly direction toward another small summit, noticing many plants of R. simsii along the way, we encountered R. simiarum at about 1250 M. on what can be described as the middle ridge of Ma On Shan. At this elevation the wind blew constantly, and again, no rhododendron grew on the South slope. Just over the ridge on the North slope, R. simiarum occurs in limited quantity. A few seed capsules were collected, but not enough for general distribution. Plants are approximately 1½ M. tall in this population and where they have protection from wind and sun were heavily branched. Leaves are quite numerous on the new growth and up to 10 cm long, assuming an upward inclined axil angle of about 60 degrees.
Being short of time, the author was not able to visit the populations of R. championae and R. westlandii (moulmainense). They occur in two separate localities and one day each is required for collecting. More time will be allotted next year and in the company of those two stalwarts Mr. Chen and Mr. Lau, I look forward to visiting more populations.