JARS v44n1 - Observations On Peninsula Malaysia Rhododendrons

Observations On Peninsula Malaysia Rhododendrons
Clive L. Justice
Vancouver, British Columbia, Canada

The twelve states of peninsula Malaysia make the bowl like shape of an overturned grapefruit spoon, with a very long Thailand handle and the island state of Singapore taking a bite out of the tip of the spoon!
Lying between the South China Sea and the Straits of Malacca across from Indonesia's Sumatra, peninsula Malaysia extends north from 03 degrees to 07 degrees at the Thai Perlis Border. Perlis is Malaysia's most northerly and smallest state.

Map of Malaysia

The states of Saba with Mt. Kinabalu and Sarawak along the north coast of the island of Borneo make up the two non-peninsula states of Malaysia. Mt. Kinabalu, a great granite massif at 13,455 feet (just over 4,000m), is the highest mountain between the Himalayas and New Guinea's Bismark Range. Mt. Kinabalu has its own special rhododendron flora. This has been reported on in the ARS Journal by Frank Doleshy of Seattle, Dave Goheen of Camas and Frank Mossman of Vancouver, Washington and Keith Wade of Vancouver, British Columbia. 1
Malaya was the old name for the peninsula with its straits settlements of Penang, Malacca and Singapore along with several sultanates. Malaysia is now the nation of twelve peninsula states and two overseas states of Saba and Sarawak. While Malaysia is a parliamentary democracy it also has a Sultan or King advisor called Agung. The Sultans of the fourteen Malaysian states elect one of their numbers for a five year term to rule over the nation. April 1989 saw the Sultan of Jahore retire when the Sultan of Perak was chosen Agung.
Malaysia the nation and country is not to be confused with Malesia. The latter is a botanical biological province that extends from peninsula Malaysia eastward to the Celebes Islands (now called Selwasi) and beyond to New Guinea. The rhododendrons in peninsula Malaysia like those in Borneo, the Philippines, Indonesia and New Guinea, are all Malesians.
There are fifteen of the Malesian rhododendrons occurring on peninsula Malaysia. These fifteen are all found in the mountains that extend down the center of the peninsula between east and west side lowland areas which are below about 975 feet (300m).
Gardens in these lowland areas (where most everyone lives) with a never varying tropical climate, regular daily rainfall and very narrow temperature range are most suitable habitats for hibiscus, Malaysia's national flower, along with frangipani (plumeria), bougainvillea and Aranda orchids. There is a period (2 weeks) when frangipani loses its leaves and gets a new crop, but it never ever is without its fragrant flowers. These plants have no definite dormancy triggered by temperature, while rhododendrons need regular diurnal temperature change to survive. This needs to be triple the usual drop of 5 degrees Celsius between day high and night low. This 15 degree drop occurs only very occasionally in the Malaysian lowlands triggering orchids like Dendrobium cuneatum , the pigeon orchid, into bloom but much too irregularly for plants like rhododendrons to survive - and anyway it's just too hot.
Of the 15 Malesian rhododendrons that occur on peninsula Malaysia, two of these, Rhododendron obscurum and R. hybridogenum are defined by Sleumer as natural hybrids. These two, however, are so rare that present day botanists in Malaysia have never seen them. So one has to take Sleumer's word that they did exist and may now be extinct on the peninsula. Aside from these two there are seven endemic rhododendrons native to peninsula Malaysia, leaving six with a wider range, to the Philippines, into Thailand over to Burma and on up into Indochina as well as over onto the islands of Java and Sumatra.
The first of the endemic species is R. perakense - named after Malaysia's second largest state Perak, which extends along the west coast between Selangor state 2 in the south and Penang state to the north. Perak is Malaysia's most mountainous state where R. perakens occurs above 1,508 feet (460 m) as both an epiphytic and a terrestrial shrub to about 4 feet in height. Leaves are small, about 1 inch long and wider beyond the midpoint, almost spatulate. Flowers are either white or yellow. Rhododendron perakense also occurs in the mountains at 1,809 feet (550 m) around the Cameron Highlands resort area. This area is in Pahang state but can only be reached through the Perak town of Ipoh.
Cameron Highlands is the equivalent for Malaysia of the colonial mountain resort areas of Simla and Darjeeling in northern India and Nuwara Eliya (pronounced Newrailya) in Sri Lanka. While there are some rhododendrons in and around Simla, more about Darjeeling, fewer in the Camerons, there is only one, R. arboreum ssp. zeylanicum in Nuwara Eliya. It is planted there as a roadside tree. While still a resort area, the Cameron Highlands is now also an area of extensive tea estates, vegetable and cut flower farms.

R. arboreum ssp. zeylanicum as a roadside 
Rhododendron arboreum ssp. zeylanicum
as a roadside tree, Nuwara Eliya, Sri Lanka.
Photo by Clive L. Justice

Rhododendron spathulatu also grows epiphytically in cloudforest trees and as a four foot high shrub on the ground. It has red solitary tubular flowers; the leaves are smaller than R. perakense , less than a half inch in length and width. It is also found in the Cameron Highlands area at between 4,920 feet (1,500 m) and 6,888 feet (2,100 m) on Mt. Korbu and Mt. Binchang. It also occurs to the south in the central Malaysian state of Pahang on Mts. Nuang and Tahan.
Rhododendron seimundi has clusters of 2 to 5 white flowers and is epiphytic on the trees in the montane rainforest or on the ground among them. The leaves on this species are even smaller and narrower than the previous two. It is a shrub to 5 feet occurring at 4,920 feet (1,500 m) on Mt. Tahan in Pahang. This rhododendron is named after E. Seimund who collected for the zoologist, C.B. Robinson, between 1916-25 in the Malay peninsula. Most of Seimund's plant collections are now at Kew.
The Malaysian equivalent of R. arboreum is R. wrayi . While it is usually seen as a shrub it can become a 30 to 40 foot high tree with a trunk 12 inches in diameter at breast height (DBH). Flowers are white flushed pink in a truss of 8 to 12 flowers with a 1 inch long corolla and a 1 inch petal flare. It has a much shorter corolla proportionately than most other Malaysians which have tubular flowers. New growth is silver grey. It is named for Leonard Wray who was appointed Superintendent of Larut Hill Gardens in Taiping, Perak in 1881. From 1881 until 1905 he was Curator of the Perak State Museum and from 1905 until 1908 he was Director of Museums, Federated Malay States also in Taiping. Wray's herbarium specimens are now at the Singapore Botanical Gardens. Rhododendron wrayi occurs at 4,264 feet (1,300 m) and higher all along the western ridge in Perak and the eastern peninsula mountains, in the interior and east coast states of Kelantan, Trengganu and Pahang. The leaves are glaucous underneath and are up to 4 inches long making them among the largest leaved of Malaysian rhododendrons.
From one of the largest to one of the smallest leaves and flowers, one finds R. pauciflorum , a terrestrial and epiphytic shrub with leaves up to an inch long and almost as broad. Rhododendron pauciflorum has the roundest leaves of all Malaysian Malesians. The red tubular flowers are indeed small, hence the specific name.
The only indigenous rhododendron to appear on a Malaysian postage stamp is R. scortechinii . Considering that there are only 15 species of rhododendrons as against 800 plus species of orchids on the peninsula the genus did well to even be considered. Rhododendron scortechinii is pictured with yellow flowers looking a bit like New Guinea's R. macgregoriae on a 20 sen (100 sen = 1 Ringgit), green background stamp. However in the wild it has red orange as well as yellow flowers. The plant is a 5 to 6 foot high terrestrial shrub occurring at 3,280 feet (1,000 m) to 6,888 feet (2,100 m) on several of the main range mountains.
Rhododendron scortechinii occurs on Genting Highlands Mt. Ulu Kali and on Mt. Benam 7,094 feet (2,163 m), Malaysia's second highest peak after Mt. Tahan 7,170 feet (2,186 m) in Pahang. The Genting Highlands like the Camerons is a resort area in Pahang state but is reached through Selangor state by an hour drive from Kuala Lumpur. Reverend Father Benedetto Scortechini was born in Anacona, Italy. He was a Roman Catholic missionary who operated in Queensland, Australia, from 1871-84. He was helped in his botanical studies by corresponding with F.M. Bailey and Baron F. von Meuller. He left Queensland for Malaysia reaching Taiping in 1884; then perhaps up from the coast via the first railroad built in Malaysia, the railroad was completed that year. Father Scortechini was appointed government botanist for Perak, a post he held until his death two years later. There is a genus Scortechnia named for him by Hooker, fils.
Taiping where both Wray and Scortechini served the colonial government is also famous for a lakeside avenue of rain trees, the largest in Malaysia, fully 6 feet DBH and with a 120 foot spread. Pithcolobium saman ( Samanea saman is the old name), is a native South American but it thrives in the humid climate of Malaysia. One would think by its phenomenally rapid growth when young to middle aged that it grew continuously night and day - but not so! As it gets dark each evening the round robinia-like leaflets fold together as if to conform to the evening call to prayers at the Mosque. A truly acculturated immigrant.

Lakeside avenue of raintrees
A magnificent lakeside avenue of raintrees,
Pithcolohium saman
, Taiping, Perek.
Photo by Clive L. Justice

Malaysia's seventh endemic rhododendron is R. robinsonii . It is similar to R. javanicum but has yellow or pale orange flowers, sometimes with a pink tinge. It is a terrestrial or epiphytic shrub occurring on the hills above Taiping and in the Cameron Highlands south to Mt. Nuangat in the 1,213 foot (370 m) to 1,640 foot (500 m) range. Most common in the Camerons - R. robinsonii like R. javanicum has leaves with an acute taper at the apex and a petiole up to 4 inches long. Robinson was born in Liverpool in 1869 and trained as a zoologist at Oxford. He journeyed to Queensland for anthropological and zoological studies and went on to the Malay peninsula to collect. In 1901 he was appointed Curator of the Selangor Museum moving up to Director of the Federated States Museums the next year. He retired 24 years later in 1926. Robinson collected with Kloss on Kedah Peak and with Seimund on Pulau Karak, with Henderson near Mt. Bentham and with Annadale on zoological collections. His botanical collections are in Kew.
The six non-endemic species of peninsula Malaysia Malesian rhododendrons are R. longiflorum , R. klossii [Syn. R. moulmainense ], R. javanicum , R. teysmannii [Syn. R. javanicum var. teysmannii ], R. jasminiflorum and R. malayanum .
R. longiflorum is a shrub or small tree either terrestrial or epiphytic with 1 to 3 inch long leathery ovate leaves with pink orange to usually coral red or crimson red flowers in clusters of 5 to 9. Petals are 1 inch across. The occurrence of R. longiflorum , ranging from 984 feet (300 m) to 3,280 feet (1,000 m), is wider and at lower elevations than any of the endemics. It occurs on Mt. Jerai in Kedah - north of Penang, in Selangor on Mt. Takun, at Kanching and Klang Gates and on Genting's Ulu Kali and Pahang's Mt. Tahan and Mt. Binchang. The author photographed R. longiflorum on the latter mountain.

R. longiflorum
The unusual needlelike seed pods of R. longiflorum .
Photo by Clive L. Justice

R. klossii is a small terrestrial tree with white flowers occurring on rocky ridges at 1,180 feet (360 m) in Pahang on Raka Bintang and in the Tras hills. The closest occurrence of this species outside of Malaysia is to the north in Indochina. Cecil Boden Kloss after whom this rhododendron is named was born in 1877 in the United Kingdom and trained there as a zoologist. He made collections in the Anambas, Andamans and Nicobars island groups off the east and west coasts of peninsula Malaysia. His main collecting areas, however, were the Indonesian islands of Java, Sumatra and Borneo.
R. javanicum , the Javanese rhododendron, is as mentioned previously very much like the endemic R. robinsonii both in leaf and flower and is quite common on the hills above Taiping and here and there on the main range.
R. teysmannii is the north Malaysian peninsula form of R. robinsonii or the other way round; the latter being the southern endemic form of R. teysmannii . This species has yellow flowers and is found on Kedah peak and Penang hill on Pulau Penang where it may possibly be included in the newly enlarged Penang Waterfall Botanic Gardens forest area. Teysmann after whom this rhododendron is named was born in Arnhem, Holland. He came out to Buitenzorg in Java as gardener to Governor General Van den Borch in 1830. From 1831 to 1869 he was Curator of Buitenzorg (Borgor) Botanic Garden. He is commemorated in a genus of plants and a periodical, Teysmannia , (pub. 1890-1922). He travelled extensively and collected in the Indonesian islands of Java, Timor and Batavia.
R. jasminiflorum is perhaps the best known of the Malaysian Malesians outside as well as inside Malaysia. It has long been used by United Kingdom hybridizers for its fragrance. A shrub both epiphytic and terrestrial on soil and rocks, it has leathery and slightly heart shaped elliptical leaves 1 to 3 inches long. The clusters of 8 to 20 white or white flushed pink flowers are a most attractive sight and have a fragrance that wafts from the plants spotted among the ferns and pitcher plants (nepenthes) on the almost vertical roadside cuts along the sides of the Cameron Highlands resort area roadways. R. jasminiflorum also occurs on Kedah peak and Mt. Ophir.

R. jasminiflorum
Rhododendron jasminiflorum ,
an 18 flower truss, held by Mr. Wong.
Photo by Woo

R. malayanum has larger leaves than R. longiflorum but the flowers have a much shorter corolla tube, 1 inch versus 2 inches for R. longiflorum - flowers of both are crimson red. R. malayanum is a 4 to 10 foot tall shrub either epiphytic or terrestrial; in this latter habitat it occurs as thickets or lone specimens. It is found in the peninsula states of Perak, Kelantan, Pahang, Selangor and Johore. While it is not endemic, R. malayanum occurs in more Malaysian states than all the other rhododendrons, so for that reason is appropriately named.
Peninsula Malaysia rhododendrons will never make it into the top ten of the rhododendron popularity stakes but for an area about the size of the Florida peninsula the Malaysian peninsula does well indeed having more than half the number of rhododendron species indigenous to the whole North American continent.
R. longiflorum mislabeled R. pauciflorum , R. jasminiflorum and R. wrayi seed collected on the author's mini expedition into the Cameron Highlands with Wong and Woo in 1988 was sent to the ARS seed exchange's Bill Tietjen. We stayed at the Old Smoke House 3 , a mock tudor kitchy hotel frequented by expatriates. It was very comfortable and had a garden with a large blue green Monterey cypress along with a beautiful blue ipomea vine (probably Ipomea learii ) covering the back roof of the kitchen.

1 ARS Journal, Vol. 31:2, Vol. 37:1 & Vol. 35:2.
2 Selangor surrounds the Federal Territory which contains Kuala Lumpur, Malaysia's capital city.
3 Liquid rubber is formed into thin sheets about the size of a bath towel, these are then cured by smoking so they can be baled and shipped. Bacon is not an item of commerce in a Muslim country.

Flora Malesiana, Vol. 1, Cyclopedia of Collectors.
Henderson, M.R., Malayan Wild Flowers , 2 vols., Kuala Lumpur Caxton Press, 1954.
Forest Research Institute of Malaysia. Ng, Francis, Director, Kampong, Selangor, Malaysia.

Clive Justice is currently ARS District Director for District #1. A landscape architect, he has traveled many times to the Far East to record and photograph rhododendrons in their native landscape. Since 1985, he has divided his time between Vancouver and Kuala Lumpur, Malaysia. Under the auspices of the Canadian Executive Service Organization, he advises the city parks department on park design and development. He recently received a certificate of appreciation from the city of Kuala Lumpur for his work there which included the creation of a National Orchid Garden and a sister garden for hibiscus, Malaysia's national flower.