Selbyana 26(1,2): 75-80. 2005.

CONSERVATION AND REINTRODUCTION OF THE NATIVE ORCHIDS OF

TIM WING Y AM* AND AUNG THAME Singapore Botanic Gardens, 1 Cluny Road, Singapore 259569 Singapore. Email: [email protected]

ABSTRACT. Some 221 of native orchids have been recorded in Singapore. Of these, however, ca. 170 orchid species are considered to be extinct, and only four are viewed as common. The orchid conser­ vation program at the Singapore Botanic Gardens aims to monitor these species, to explore ways to conserve their germplasm, and to increase their number for subsequent reintroduction into appropriate habitats, including managed parks and roadsides. Thus far, we have successfully reintroduced Grammatophyllum speciosum, Bulbophyllum vaginatum, and Bulbophyllum membranaceum. Recently, we initiated the Orchid Cryo-Seed Bank Project, and have managed to successfully store seeds of four native species. They are Dendrobium crumenatum, Spathoglottis plicata, Bulbophyllum vaginatum, and Dendrobium anosmun.

Key words: conservation, reintroduction, seed bank, Singapore, native, orchids

INTRODUCTION METHODS: HABITS AND HABITATS

Singapore is located at ca. 1° north of the Native orchids in Singapore can be divided by habit into two main groups: epiphytes and equator, off the southern tip of the Malay Pen­ terrestrials. They also can be grouped according insula between the South Sea and the In­ to habitat, including open areas, semi-shade, and dian Ocean. The nation consists of the main is­ low-sunlight forest floors. land of Singapore and 58 nearby islands. The total land area is ca. 690 km2• The whole island consists of mostly lowland. The highest point is Epiphytes at Bukit Timah, which reaches an elevation of No other better illustrates the epiphytic 165 m. The equatorial climate has a relatively orchids of Singapore than the Dendrobium spe­ uniform temperature and high humidity. A ver­ cies, almost all of which are epiphytes. The larg­ age daily temperatures fluctuate between 25.2°C est genus among the native orchids, Dendrobium and 32°C. Annual rainfall is ca. 1700 mm, with consists of 38 species (Tan 1984) or more than the wettest months November-January. 20% of the total number of orchids in Singapore. Singapore is a modem city, yet it has many interesting types of natural habitats. The heart of Dendrobium crumenatum. The pigeon orchid (D. crumenatum) is a well-known native the main island has a primary rain forest and a species that can commonly be seen growing freshwater swamp forest. In addition, some man­ on the trunk of roadside trees. It is a delight groves remain along the coast. Other habitats to find them in bloom, as the are consist of secondary forests, shrub, grasslands, sweetly scented. The species flowers 9-10 and urban parks and fields. days after a heavy rainstorm. Similar flow­ Of the 221 species of native orchids recorded ering patterns have been observed in some in Singapore (Keng et al. 1998), more than 90% native Bulbophyllum, Thrixspermum, Brom­ are endangered, vulnerable, rare, or extinct. This headia, and Taeniophyllum species. estimate is based on lists in a preliminary report Dendrobium leonis section Aporum. Another on the conservation status of native to interesting but rare native orchid, D. leon is, Singapore (Ng & Wee 1994, Tan 1995). The has that are laterally flattened, thick Singapore Botanic Gardens, therefore, has initi­ and fleshy, and alternate in two rows. In­ ated an orchid conservation program to monitor dividual yellowish-green flowers are borne these species, to attempt to find ways and means near the apex of the stems. The flowers are to conserve their germplasm, and to increase only 1.5 cm across and have an extremely their number for subsequent reintroduction into sweet vanilla-like fragrance that can be de­ appropriate habitats in nature reserves, parks, tected from a distance of 5 m. and roadside trees. Dendrobium aloifolium section Aporum. The native orchid D. aloifolium bears flowers 4 mm in diameter, probably the smallest in * Corresponding author. the section. 75 76 SELBYANA Volume 26(1,2) 2005

Dendrobium grande section Aporum. The na­ lip, white with a pale yellow tip, is hairy in tive orchid D. grande has yellowish-green the middle. flowers, ca. 9 mm wide, tinted with red near Cymbidium finlaysonianum. The most com­ the base of the and , and the mon of the three Cymbidium species in Sin­ lip is deeply clefted. gapore is C. finlaysonianum. Other species Dendrobium anosmum (syn. Dendrobium su­ are C. bieolor var. pubescens and C. aloi­ perbum). Although widespread in Southeast folium. All native Cymbidium species are , this orchid species can no longer be epiphytes. found in Singapore. Dendrobium anosmum Coelogyne pandurata. Among the four native produces 1-4 large fragrant flowers at each species of the genus Coelogyne, C. pandur­ node on leafless pendent stems. The flowers ata is the most outstanding. The is range in color from dark rose to deep lav­ ca. 6.5 cm across. Its petals and sepals have ender. The hairy lip is usually marked with an attractive, clear apple-green color. The deep purple stripes in the throat. protruding lip has some conspicuous dark Bulbophyllum vaginatum section Cirrhopetal­ brown/red, almost black markings, hence, um. The second largest orchid genus in Sin­ its common name, the black orchid. gapore is Bulbophyllum. Species of this ge­ Thrixspermum amplexicaule. Several species nus are divided into many sections. Of the of the genus Thrixspermum, which is most­ 28 recorded species (Tan 1984), B. vagina­ ly epiphytic, have been recorded in Singa­ tum is one of the most unusual. It grows in pore. Thrixspermum amplexicaule (syn. T. fairly exposed areas. Some plants grow nat­ lilacinum) is the most attractive, with a pale urally on branches of rain trees (Samanea lilac-colored flower ca. 3 cm in diameter. saman) and on Eugenia grandis in the Sin­ The plant was first found in a semi-aquatic gapore Botanic Gardens. The plants usually habitat in Singapore. cover an extensive area of a branch and pro­ Thrixspermum trichogiottis. Also found in duce a spectacular sight when in full bloom. natural areas in Singapore, T. trichoglottis The flowers are creamy-yellow with ca. 15 is very small with long seed capsules. The of them arranged in a fan shape whorl or in flowers are creamy yellow, with a brown a circle at the tip of the scape. spot on the lip. Among the other species of Bulbophyllum medusae. One of a number of this genus are T. calceolus, T. notabile, and interesting Bulbophyllum species in Singa­ T. ridleyanum. pore, B. medusae, another native orchid, re­ Grammatophyllum speciosum. Although Sin­ sembles B. vaginatum but has paler and lon­ gapore is a small country, it is the home of ger lateral sepals (12 cm). the largest orchid plant in the world, G. spe­ Bulbophyllum membranaceum. In the Buk:it ciosum. Also known as the tiger orchid, be­ Timah Nature Reserve, a clump of B. mem­ cause of the markings on the flowers that branaceum is found creeping on a large resemble the skin of a tiger, it is extremely piece of granite. Among the smallest native rare if not already extinct in the wild in Sin­ orchids, it has very small flowers ca. 6 mm gapore. Grammatophyllum speciosum was long that do not open completely; the upper last found in the wild in Tuas and Pulau is pale yellow, whereas lateral sepals Ubin (Ridley 1900). Since a mature plant are dark red, and the petals, 1.5 mm long, could weigh more than a ton, it is a wonder appear translucent. Other interesting Bul­ that such a huge plant could live on the bophyllum of Singapore are B. purpures­ trunk of a tree. cens, B. lepidum, and B. blumei. Taeniophyllum obtusum. The extraordinary Vanilla griffithii. The Vanilla genus, among the genus Taeniophyllum, the "leafless" orchid, most widely distributed in the world, has ca. has stems greatly reduced in size and cov­ 100 species distributed throughout the trop­ ered by scale-like leaves. are fleshy ics, from Central and South America, across and spread over the bark of the host tree, Central , Southern , Sri Lanka, usually on top of a thin layer of moss. These and all of to the Pacific Is­ green roots replace leaves as the photosyn­ lands. In Singapore, the genus is represent­ thetic organ. As the plant is almost flat and ed by V. griffith ii, a relatively common epi­ its color blends very well with its host, one phytic climber found in the Upper Pierce can hardly spot them in the wild. Taenio­ Reservoir, Nee Soon, and the Mandai For­ phyllum obtusum can be found near est. The plant climbs on tree trunks in a swampy areas in Singapore. The roots of zigzag fashion. Petals and sepals of the the plant are ca. 2-3 mm wide. Flowering flower are white, flushed with pale green, is gregarious, with the flower 5 mm wide; 2.5-3 cm long and 1.4-1.5 cm wide. The petals and sepals are orange-yellow, and the SECOND IOCC PROCEEDINGS 77

lip is fleshy and concave, and white in color. Nephelaphyllum pulchrum. Among the group Flowers only last for one day. Some of the of native orchids that dwell on the forest Taeniophylium species are known to pro­ floor in Singapore, N. pulchrum thrives duce a sweet fragrance that attracts polli­ where the light intensity usually does not nators. exceed 3000 lux during most of the day. Only occasionally do sunrays manage to Other beautiful native epiphytes include Po­ penetrate the canopy to reach the forest matocalpa latifolia, Arachnis hookeriana, Rhyn­ floor. This native orchid has very interesting chostylis gigantea, Renanthera histrionica, Pha­ and showy leaves and delicate flowers. The laenopsis cornu-cervi, Liparis elegan~, Liparis leaves are fleshy; they are mottled light and hyacinthoides, Eria javanica, Eria pudica, Eria dark green and flushed with purple. The pulchella, Dipodium pictum, Ariopsis javanica, flowers tend to crowd together on the short and Flickingeria comata. Some of these are ex­ spike. The pinkish sepals and petals that all tremely rare if not extinct in Singapore. curve downwards are ca. 1.3 cm long. Calanthe pulchra. Another forest-floor dweller, Terrestrials C. pulchra has striking orange flowers that do not open completely. The flowers are Of the total number of native orchid species densely crowded along the 50-60 cm long in Singapore, ca. 25% are terrestrials. These spe­ inflorescence. A distinguishing feature of cies can be found either in open areas or dwell­ the flower is that its spur curves up like a ing in the shade on forest floors. hook. The leaves can reach a length of 70 Spathoglottis plicata. One of the most common cm and a width of lO cm. terrestrial orchids in Singapore, S. plicata, Plocoglottis javanica. Quite a common terres­ frequently is found in open areas of the Bu­ trial orchid in Singapore, this inconspicuous kit Timah Nature Reserve and the Central forest-floor dweller has long pseudobulbs, Catchment. It usually grows among grasses which bear a single . The leaves are 35 and ferns. The local species has two varie­ cm long by lO-12 cm wide. The long flow­ ties: the dark pink and the alba forms. er spike carries some yellow flowers that Spathoglottis plicata is very free flowering are spotted with red. and has been used for landscaping. Cystorchis variegata. Unlike Plocoglottis ja­ Arundina graminifolia. Another common ter­ vanica, C. variegata is a very rare species. restrial species is A. gramin(folia. Often This native forest-floor dweller has very at­ found growing in habitats similar to those tractive foliage. The leaves are arranged to­ of Spathoglottis plicata, A. graminifolia is wards the apical part of the . They very free flowering in the lowland tropics. are light green in color with a darker net­ The vegetative parts of A. gramin!folia re­ work of venations. The half-opened flowers semble bamboo, which accounts for its are borne on the elongated flower spike; the common name, the bamboo orchid. sepals are brown with a tinge of pink while finlaysoniana. Among the native the petals are white. orchid species that prefer semi-shade, the Claderia viridiftora. Also found on the forest familiar B. finlaysoniana is usually found floor of Singapore, C. viridiflora has a flow­ along roadsides or on hill slopes. Like Den­ er spike that bears a succession of many drobium crumenatum, B. finlaysoniana flowers, one or two at a time. The flowers flowers a few days after a rainfall. The are greenish, sepals and petals are ca. 2.5 flower is very attractive, faintly scented, cm long. white, with a yellow patch on the lip. Un­ Zeuxine clandestine. Among the less-known fortunately, the flowers only last for a few orchids found in Singapore is Z. clandes­ hours. tine. Quite a large population of the species Eulophia graminea. One of two species of the has been found in Bukit Timah, growing on genus Eulophia found in Singapore, E. gra­ the floor of a secondary forest. The plant is minea is a very hardy plant. It grows among an inconspicuous creeper, with a fleshy rhi­ grasses and in partially shaded hill slopes zome. A young plant lies rather close to the and wastelands. ground, just like grass. When it begins to Eulophia squalida. Found in the Bukit Timah bloom, a flower spike of ca. 10-20 cm pro­ Nature Reserve growing on a rather steep trudes from the ground, bearing many small slope, E. squalida has a flower with an un­ flowers. The flowers are light green in color usual color. The sepals are brownish-olive and hardly open. The sepals are hairy, and and the petals white. The lip is pale mauve ca. 3 mm long. The lip is a little shorter than and has a white central area. the sepals. 78 SELBYANA Volume 26(1,2) 2005

Didymoplexis pallens. This species is an ex­ Choa Chu Kang, Jurong, Ang Mo Kio, and Ser­ ample of another group of terrestrial orchids angoon, where native orchids used to thrive, no that dwell on the forest floor but are my­ longer exist. Thus an orchid conservation pro­ cotrophic (Arditti 1992). These orchids are gram was initiated to monitor these species and parasitic on the fungi that associate with to attempt to find ways and means to conserve them. All orchids rely on mycorrhizae for their germplasm and to increase their numbers their early growth, but the mycotrophic or­ for subsequent reintroduction into appropriate chids depend on the fungus to provide them habitats in the nature reserves, parks, and road­ with nutrients throughout their life. These side trees. The strategies being explored by the species usually dwell on the forest floor un­ Singapore Botanic Gardens are (1) propagation der dense canopy, in areas where little light and reintroduction, and (2) cryo-seed banks. can reach. pallens, found in Bukit Timah Nature Reserve, has a fleshy Conservation and Reintroductiou underground rhizome; the flower spike is soft and slender, bearing several flowers. First, we want to propagate species vegeta­ The flowers are pale brown-olive, with a tively and by in-vitro culture. To increase the tinge of pink, ca. 1.4 cm long. The dorsal population of some of the rarer species, which sepal fuses to the petals for half its length; will be either selfed or sibbed, seeds are ger­ lateral sepals are also joined to the petals minated in vitro (Yam & Weatherhead 1988), towards the base. The lip is light yellow, ca. and seedlings are introduced back to nature. So 5 mm long. The species is not easily seen, far, we have managed to propagate a number of because it has no visible vegetative part ex­ orchid species and have reintroduced three spe­ cept for the erect flower spike, which hardly cies to nature areas in Singapore: Grammato­ can be noticed in its natural habitat. If a phyllum speciosum, the tiger orchid; Bulbophyl­ flower is pollinated, however, the seed cap­ lum vaginatum; and B. membranaceum. sule can be seen in the wild. Owing to the H.N. Ridley, an early director of the Singa­ difficulties in locating the plant, very little pore Botanic Gardens, recorded that the tiger or­ is known about this orchid. Last year, we chid was found in the wild in Toas (Tuas) and also discovered another mycotropic orchid, Pulau Ubin (Ridley 1900). Unfortunately, natu­ Leucanorchis multiflora, at the Bukit Timah rally occurring plants are now extinct. Nature Reserve. A few years ago, a tiger orchid growing in the Gardens flowered and was self-pollinated. The Among the beautiful jewel orchid species re­ huge seedpod was harvested 7 months later. corded in Singapore are Anoectochilus alboli­ Seeds germinated a month after being sown on neatus and Macodes petola; and examples of Knudson C medium (Knudson 1946). After 12 other native terrestrial orchids are Corymborkis months in the laboratory, the seedlings were veratrifolia and Phaius tankervilleae. Several planted out in the nursery. forest-floor primitive species also can be found, Since the tiger orchid last occurred naturally such as Apostatasia nuda and Neuwiedia vera­ in Pulau Ubin, the first batch of seedlings was trifolia. reintroduced there in July 1999, when the seed­ lings were 26 months old and ca. 15-20 cm tall METHODS AND MATERIALS with 5-6 leaves. They were affixed on durian, rambutan, mango, angsana, tembusu, and rain Based on lists in a preliminary report on the trees. Seedlings also were planted on trees in the conservation status of plants native to Singapore Botanic Gardens, around the Visitor Centre at (Ng & Wee 1994, Tan 1995), ca. 170 of Singa­ the Bukit Timah Nature Reserve, and in the Or­ pore's 221 species of native orchid species al­ chard Boulevard area in the heart of the city. ready are considered to be extinct, and only four With experience from the initial trials, we de­ are viewed as common. The remaining species cided to introduce seedlings to the Bukit Batok are placed within the "Endangered," "Vulner­ Nature Park in early 2001. This time, the seed­ able," and "Rare" categories or have an inde­ lings were more mature, ca. 30-40 cm tall with terminate status. This means that more than 90% 16-20 leaves. They had at least three shoots, a of the native orchids in Singapore are endan­ well-established system, and fleshy pseu­ gered, vulnerable, rare, or extinct. dobulbs. In February 2001, these larger seed­ A comparison of habitats on the Island of Sin­ lings were planted on trees along Orchard Bou­ gapore 150 years ago and today shows that most levard and on the yellow rain trees around the of the mangrove and marshy areas have been Bandstand in the Botanic Gardens. In April replaced by industrial estates or residential areas. 2001, seedlings of the same age were introduced Forest and mangrove areas, such as those at to a site adjacent to a mangrove area in Pulau SECOND IDCC PROCEEDINGS 79

TABLE l. Survival rate of reintroduced seedlings of ciosum. The size of seedlings (TABLE 1) also is Grammatophyllum speciosum, the tiger orchid, to a key factor in determining survival. Seedlings various parts of Singapore. with 16--20 leaves (30-40 cm tall) tend to sur­ vive better than those with only five leaves (15- Seedling Survival 20 cm tall). size rate Location cm % We hope that the tiger orchids will continue to thrive in their new homes. In the near future, Pulau Ubin 15-20 35 more of this beautiful and majestic species will 30-40 90 find its way to more nature areas and parks in Bukit Timah Nature Reserve 15-20 10 30-40 75 Singapore. Botanic Gardens 15-20 10 In 2003 and 2004, two other native orchids, 30-40 70 Bulbophyllum vaginatum and B. membranaceum Orchard Boulevard 15-20 45 were successfully propagated and reintroduced. 30-40 90 Seeds of these species were collected from Bukit Batok Nature Park 30-40 90 plants growing in their natural habitats. The Holland Road 30-40 95 seeds were sown on Knudson C medium. Seed­ Upper Pierce Reservoir 30-40 95 lings were grown on the media until 2-3 cm tall before being transferred to the nursery. Some ten seedlings were planted on fern barks measuring Ubin, and in early May 2001 again to the Bukit 7 cm long by 5 cm wide and grown at the nurs­ Timah Nature Reserve. Some 40 seedlings also ery for 6 months, until new shoots began to de­ were planted on rain trees along Holland Road. velop. They were then reintroduced. Host trees In December 2002, some 40 seedlings were were selected based on the same criteria used planted on trees at the Upper Pierce Reservoir. for reintroducing the tiger orchid. When a suit­ In early 2004, some 20 plants were planted at able tree is selected, fern barks with established various urban parks, such as Sembawang Park, seedlings were secured on the tree trunk by Kent Ridge Park, and Tiong Bahru Park. Our nails. aim is to use native orchids to educate the public Thus far, some 500 seedlings of Bulbophyllum about our rich natural heritage and our respon­ vaginatum and B. membranaceum have been re­ sibility to conserve it. introduced. More than 90% have settled down The tiger orchid seedlings we planted have and are growing well in their new homes. We been growing for 2-5 years in their new homes, have learned that these seedlings are best plant­ and a majority of them are doing well. New ed in slightly shady areas, with at least 50% shoots have developed, and roots are firmly es­ shade to avoid being scorched. We are very tablished on tree trunks. Unfortunately, most pleased to report that most of these seedlings seedlings planted in the Bukit Timah Nature Re­ have produced new shoots and are growing onto serve were damaged or removed by animals the bark of the host tree. (probably by squirrels and monkeys respective­ ly) (TABLE 1). Orchid Cryo-Seed Bank Several factors appear to play major roles in the survival of introduced seedlings. These in­ The second conservation strategy is to store clude the microclimate of the area (relative hu­ orchid seeds under liquid nitrogen as part of an midity, for example), texture of the bark of host Orchid Cryo-Seed Bank Project. Why do we trees, presence of other epiphytes, and the size store seeds in liquid nitrogen? Although tropical of the seedlings. orchids have been grown routinely from seed for Seedlings planted in areas with high relative many years, using the asymbiotic method for humidity tend to survive better than those in dry seed germination, relatively little progress has areas. For example, in Pulau Ubin, seedlings es­ been made in developing techniques for storing tablished in a damp area inside a secondary for­ the seeds. Storage is becoming increasingly im­ est are healthier and more vigorous than those portant, however, in view of the rapid loss of growing near the sea where the breeze tends to many species caused by habitat destruction and dry the bark faster. Texture of the bark is im­ over-collection. The reason for storing seeds un­ portant because certain barks tend to retain more der such low temperature is simple. When plant moisture. For instance, rain trees are generally and animal tissues are stored at ultra-low tem­ better hosts than tembusu. Trees that. support peratures, such as that of liquid nitrogen more epiphytes tend to be better hosts than those ( -196°C), metabolism is effectively stopped and with fewer epiphytes. It seems that if the con­ cells are preserved without deterioration until ditions are suitable for other epiphytes, they also such time as they are thawed for use. are more appropriate for Grammatophyllum spe- There are several reasons for the cryopreser- 80 SELBYANA Volume 26(1,2) 2005 vation of orchid seeds: (1) Seed storage ensures healthy, mature seed capsules. (2) Desiccate the against failure to germinate or the accidental seed for several days in a desiccator that con­ loss of seedlings. (2) Instead of keeping hun­ tains a saturated solution and calcium chloride. dreds of plants in the nursery, thousands of or­ (3) Transfer a small quantity of dried seeds to a chid seeds (which are very small), can be stored 2-ml cryogenic vial. (4) Store the vial in a liquid in a small container. If stored under the proper nitrogen freezer. conditions, the seeds can be kept for years under To conclude, although remarkable progress such conditions. The seeds can be sown as and has been made, cryobiological storage remains when the need arises. The seeds also can be dis­ a relatively new science, but one which holds tributed to (or exchanged with) other botanic in­ promise for the long-term storage of germplasm. stitutions for conservation. (3) Seeds of hybrids The freezing of plant samples at a low temper­ can be stored as well, once the technique is per­ ature is still in a highly empirical state. Cryo­ fected. This will allow assessment of the com­ preservation offers a practical, efficient, and mercial merits and potential of a particular cross economical tool for long-term storage of germ­ while still retaining a proportion of the seeds. plasm. Tropical species cryopreservation has not (4) Plant germplasm collections form an integral been studied extensively, because these plants part of all plant-breeding programs. The purpose are known to be more sensitive to chilling, low of germplasm preservation is to ensure the avail­ temperature, and desiccation than are temperate ability of useful germplasm at any time. Germ­ species. Therefore, a considerable amount of re­ search still needs to be conducted, before we can plasm storage in the form of seeds is economical use the technique confidently for long-term pres­ and efficient. ervation of orchid seeds. At the moment, we are During the last 2 years, we carried out a series experimenting to fine-tune the storage procedure of experiments to investigate the optimal con­ and determine if we can use it to store seeds of ditions for storing some native orchid seeds. We other species and hybrid orchids. studied the effects of pre-storage treatment such as desiccation, effectiveness of various desic­ LITERATURE CITED cants, duration of desiccation, age of seeds, and different types of containers. Arditti, J. 1992. Fundamentals of Orchid Biology. Wi­ Thus far, we have managed to successfully ley-Interscience, New York. store seeds of four native species. They are Den­ Keng, H., S.c. Chin, and H.T.W. Tan. 1998. The Con­ cise Flora of Singapore. Vol. II: . drobium crumenatum, Spathoglottis plicata, Singapore University Press, Singapore. Bulbophyllum vaginatum, and Dendrobium an­ Knudson, L. 1946. A new nutrient solution for the ger­ osmun. The first three species are still common mination of orchid seed. Amer. Orchid Soc. Bull. in Singapore. The last one can no longer be 15: 214-217. found in Singapore. To carry out the systematic Ng, P.K.L. and YC. Wee, eds. 1994. The Singapore investigations, we need a large quantity of seeds; Red Data Book: Threatened Plants & Animals of hence the three common species were used. Singapore. Nature Society (Singapore), Singapore. Ridley, H.N. 1900. Flora of Singapore. J. Straits Some of the seeds have been stored under liquid Branch Roy. Asiatic Soc. 33: 27-196. nitrogen for more than 24 months. Recently, we Tan, H.T.W., ed. 1995. A Guide to the Threatened attempted to germinate the stored seeds and are Plants of Singapore. Singapore Science Centre, pleased to report that more than 90% of the Singapore. seeds remained viable. This gives us a great Tan, W.K. 1984. Orchid species of Singapore. pp. 8- sense of excitement. Seeds of tropical orchids 12 in Proceedings of the Fifth Asian Orchid Con­ gress. Park and Recreation Department, Ministry can be preserved under - 196°C after all! From of National Development, Singapore. the results of the experiment, we find the best Yam, T.W. and M.A. Weatherhead. 1988. Germination procedure for storing the seeds that we have test­ and seedling development of some Hong Kong ed is as follows: (1) Collect fresh seeds from orchids. I. Lindleyana 3: 156-160.