
Orchid diversity in Merauke, South Papua Province, West Papua
11 December, 2024Share:
Orchid diversity in Merauke, South Papua Province, West Papua

by Kharisma Pammai, Mimien Henie Irawati Al Muhdhar, Murni Sapta Sari, Sueb, and Wachidatul Linda Yuhanna
Orchids (Orchidaceae) are a family with the largest diversity among flowering plants. Indonesia as a tropical country has a high diversity of orchids with estimated 4000-5000 species, yet only about 1500 species have been identified. Papua is one of the islands in Indonesia famous for its high and unique flora biodiversity. A study estimates that there are about 2,869 orchid species in Papua Island, most of which are endemic to this island. Nevertheless, exploration and data collection of orchids in the Indonesian Papua region is relatively limited compared to Papua New Guinea and Java Island, so there are still many Papuan orchid species that are not widely known. Data collection needs to be done periodically to monitor changes in the level of diversity of orchid species in the region.
One of the areas in Papua island that has a high diversity of natural orchids is Merauke District. Merauke District is located in the West Papua, Indonesian, which shares a boundary with the state of Papua New Guinea. This area has a unique orchid species similar to orchids in Australia and Papua New Guinea, however, not much information is available regarding the orchid diversity in Merauke. A study on the biodiversity of orchids in the southern part of Papua, including Merauke, was only able to reveal the taxonomical information of 76% of species, while the remaining 24% were not identified.
Many orchid species in Merauke District have not yet been known in detail, suggesting that further taxonomical work is required. The study also explained that only 10 species of orchids had been domesticated by the communities. Some are sought after by collectors while the rest are considered to have no horticultural and economic value. Orchid diversity in Merauke and found 41 species of orchids, consisting of 4 terrestrial and 37 epiphytic orchids with some of the epiphytic orchids were endemic to Papua and Papua New Guinea. The study also showed that the diversity of orchids in Merauke District was classified in the moderate category.
Despite the high diversity and less exploration, the existence of orchids in Papua, including Merauke, is threatened by several factors, mainly habitat loss. This is because Papua is one of the provinces being targeted for regional development which might drive deforestation and forest degradation, threatening the habitat of natural orchids. Further, the problem is exacerbated by the overexploitation of certain orchid species, which are the prima donna of collectors and have high economic value. In addition to anthropogenic threats, biotic factors might cause a decline in orchid populations, such as a decrease in the number of pollinators due to reduced forest heterogeneity, reduced mycorrhizal numbers due to soil erosion, and the effects of global climate change. Climate change causes an increase in temperature which might drive the habitat of several species, including epiphytic and terrestrial orchids, to shift into areas with cooler climates. Also, the hotter climate might induce forest fires which lead to orchid death and habitat loss.
Therefore, this study aims to collect data on the diversity of orchids in Merauke District after nine years from the initial research from 2013 to 2022. We conducted a botanical expedition in some areas in Merauke and compared the results of this study with the previous one to see the changes in orchid diversity. This study aims to inventory orchids in Merauke, South Papua as Indonesia’s natural wealth. We expected the results of this study might provide insight into developing conservation strategies for orchids, especially in Merauke District.
Study Area
Exploration and collection of natural orchids were carried out in the forest area of Merauke District, South Papua Province, Indonesia with coordinates 6o00′-9o00′ S and 137o-141o E. This location shares boundaries with districts of Boven Digoel and Mappi to the north, Papua New Guinea to the east, and the Arafura Sea to the south and west. The observation covered the forest area of Merauke, Semangga, Kurik, Tanah Miring, Jagebob, Sota, Elikobel, and Ulilin Sub-districts with a total area of approximately 15,233.26 km2. The altitude in this area is 0-60 m asl. with a temperature of 23.2-30.8oC, annual rainfall of 1558 mm and humidity of 78-81%. Most of this area is an organosol, alluvial, and hydromorphic swamp. The research was carried out for six months, from June to December 2020.

Map of surveyed areas in the Merauke District, South Papua Province, Indonesia, covering sub-districts of: 1. Ulilin, 2. Elikobel, 3. Jagebob, 4. Kurik, 5. Tanah Miring, 6. Semangga, 7. Merauke, and 8. Sota
Data collection was carried out using the exploratory or roaming method. The roaming method was conducted by exploring or tracing forest areas along forest trails commonly used by local people or creating new paths, and collecting any samples of orchid plants found. The samples found were observed, collected the data and documented using photographs. Unidentified orchids were collected as herbarium for further identification. The tools and materials used in the research included GPS, compass, binoculars, machete, caliper, loop, ruler, newsprint, plastic bag, hanging label, stationery, DSLR camera, distilled water, 70% alcohol, and altimeter.
RESULTS AND DISCUSSION
In this study, it was found that the genus that had the highest number of species was the genus Dendrobium which consisted of 33 species. Dendrobium is a genus that is easily adaptable and can grow in a variety of habitats and environments, such as in the lowlands or highlands or mountains, on the coasts of small islands, in moist forests near rivers or beaches, on cliffs and even on rocks. Dendrobium is one of the largest orchid genera in the world with around 2000 species. Dendrobium is widespread in Asia, Australia and Europe, India, Sri Lanka, China, Japan, Korea, the Pacific Islands, New Caledonia and New Guinea. Around 614 species have been recorded in New Guinea, making Dendrobium the second largest orchid genus in New Guinea, and especially in Papua, eastern Indonesia, there are many Dendrobium species and also the best species.
The district or sub-district that has the richest diversity of orchids is the Ulilin Sub-district. This Sub-district has an area of 5,092.57 km2, the topography is undulating with a slope of 8-12%, is located at an altitude of 90 meters above sea level, classified as a dry area with several rivers flowing in it. This research is a re-inventory of orchid species in Merauke District, which in 2013 was investigated. In this study, as many as 65 orchid species belonging to 23 genera were recorded, consisting of 57 epiphytic orchids and 8 terrestrial orchids. There were two orchids unable to be identified to species level, namely Dipodium sp. and Oberonia aff. titania, and there were two natural hybrid orchids of the genus Dendrobium.
Based on our study, as shown in Table 1, there were 10 endemic Papuan orchids. All orchid species found in Merauke District are included in the Appendix II list of CITES (UNEP-WCMC 2021), and in this study one species was included in Appendix I. In addition, there were 19 orchids listed in the IUCN Red List. Among the 65 species identified in this study, several of them are orchids with high economic value, so they are in great demand by orchid lovers (Figure 2). Dendrobium became the genus with the most species found, namely 33 species. There were 10 endemic orchids, namely B. digoelense, B. phalaenopsis, D. devosianum, D. lasianthera, D. lineale, D. macfarlanei, D. poneroides, G. scriptum, P. glanduliferum, and S. papuana.

Orchid species in Merauke that have high economic value: A. D. spectabile, B. D. nindii, C-D. D. trilamellatum, E. D. lasianthera, F. G. speciosum, G. P. amabilis, H. D. discolor, I. V. hindsii, J. D. mirbelianum, K. C. asperata, L. D. bigibbum, M. P. glanduliferum, N. D. Antennatum
List of orchid species in some areas in Merauke District, South Papua Province, Indonesia

Note: IUCN: the International Union for Conservation of Nature with classification of NT: Near Threatened, LC: Least Concern, EN: Endangered; CITES: the Convention on International Trade in Endangered Species of Wild Fauna and Flora
Discussion
The number of orchids found in this study was significantly different from the initial research conducted by Pammai et al. at the same location. Pammai et al. found that there were 41 orchid species which was much fewer than in our study. They were 25 orchids species that we recorded but not in the study by Pammai et al. (2013), such as B. Baeleyi F Muell, B. digoelense J.J.Sm, B. fractiflexum J.J.Sm and so on (see Table 1 with an asterix sign). Nonetheless, there were some orchids found during exploration in 2013, but no longer found in 2020, namely, B. macranthum, B. phalaenopsis, D. bigibbum, P. amboinensis, and P. pubescens.
The number of species recorded in our study was higher compared to the previous study by Pammai et al. possibly because it differs from previous studies due to the larger area and favorable natural conditions and does not necessarily suggest increased conservation. On the other hand, the loss of some species might be due to changes in forest function in Papua. Based on a report by Forest Watch Indonesia that the area of forest in Papua, including Merauke, continues to decline caused of the conversion of forest into plantations or infrastructure development to improve the economy. The loss of tree cover reduces the forest canopy, which affects the microclimate and changes the natural habitat of epiphytic orchids. Habitat change and fragmentation also have an effect on decreasing genetic variation and increasing inbreeding. This condition is the result of a decrease in pollinator variation due to a decrease in plant diversity in the forest. Furthermore, it can trigger the loss of certain orchid species that require special pollinators and specific habitat conditions.
Human interference that changed the natural habitat of orchids into secondary forests affected the distribution and abundance of orchids. The condition of this study is also almost the same as the conditions in Papua where many primary forests are converted into settlements and plantations. Human interference has an effect on air pollution which affects the pH of the tree bark where epiphytic orchids attach and affect the increase in air temperature. Changes in pH and temperature affect the microclimate of the orchid to be unsuitable.
There is a small population of terrestrial orchids that is able to survive in fragmented forests that have not been logged even though the surrounding area is already logged. The area still has a forest canopy that is good enough for sunlight to penetrate and provides a fairly tolerant environment for orchids. However, in this study, epiphytic orchids had a high abundance in the logging area. This is because in the logging area many tree trunks fell, where many species of epiphytic orchids were found and survived. It is also supported by the quite great adaptability of epiphytic orchids to dry and hot conditions, especially the species found are the Epidendroideae subfamily, which is known for its good adaptability in extreme conditions.
These human activities have an effect on the loss of trees in the forest which are hosts for epiphytic plants, including orchids. The study stated that changes on a geographical scale in terms of size, shape and habitat isolation affect the structure and abundance of orchids in a place. This is in line with this study where changes in habitat conditions affect the dynamics of orchid diversity in Merauke District. The decline in the population of a species is also influenced by the existence of massive habitat fragmentation. However, information regarding orchids in Lanny Jaya that have not been discovered remains limited, suggesting further research in the future once new accessibility is available in the area.
All 65 recorded species in this study were listed in appendix II of CITES, implying that although the species are not necessarily threatened with extinction, but their trade must be controlled to avoid overexploitation (CITES 2022). One species is listed in Appendix I CITES, meaning that it has conservation concerns and trade is only allowed under a very strict regulation (CITES 2022). One species is included in the IUCN Endangered (EN) category, implying that the species faces a high risk of extinction in the wild. Two species are included in Near Threatened (NT), meaning that the species is threatened with extinction in the near future but does not yet qualify as Critically Endangered (CR), Endangered (EN), and Vulnerable (VU). There are 19 species that are included in the IUCN Least Concern (LC), meaning that these species have been evaluated yet do not meet the criteria under the CR, EN, VU, or Near Threatened (NT) categories. There are 10 endemic species because of the limited distribution and only found in certain locations, making these orchids vulnerable to extinction.
As many as 14 species are considered to have high economic value, so they are widely cultivated and favored by the community. The high public attraction to several species of orchids causes overexploitation. Natural orchids are often collected and sold by collectors illegally, exacerbating the scarcity of high-value orchids. However, this is not balanced with good.
Acanthephippium spp.
Acanthepippium has 11 species spread across Southeast Asia to the Pacific Islands, but in Papua only one species was found but not endemic. This genus has a characteristic of its jug-shaped flowers so that it is easily distinguished from other genera. The shape of the flower makes this orchid often referred to as the jug orchid. It grows terrestrially in the shade of dense trees in fairly thick leaf litter near rivers and lives at an altitude of 0-1300 m above sea level. Plant height can reach 80 cm with roots with a diameter of 0.3-0.4 cm along 26 cm. Pseudobulbs are oval to fusiform, covered with stiff fibers, and have 2-3 leaves. Leaves broad oblong with thick veins on the underside, measuring 30-46 x 10-14 cm. In this study, one species from this genus was found, namely Acanthephippium splendidum. It had flowers with a yellow-orange base color, very fleshy, yellow labellum with red markings inside, sepals with red stripes and red spots, yellow petals with red-orange markings, the color was less bright.
Acriopsis spp.
The name Acriopsis comes from the Greek language, referring to the shape of the flower column that resembles a grasshopper. In general, flowers of the genus Acriopsis are difficult to distinguish, but the lip of the flower can be a characteristic of each species. Acriopsis grows epiphytes with pseudobulbs shaped like green onions and clusters that support 3-4 linear leaves and become wrinkled and glabrous with age. Acriopsis flower size <2 cm, so it is less desirable as a cross breeder because it is considered less attractive.
In the studied area, A. liliifolia was found in coastal swamp forests on trees in the savanna growing above ant nests on trees. This species is almost always found in association with ants that nest in and under the roots. The flowers are very small, cream colored with white lips, there is a yellow stripe along the midline of the sepals, petals, and lips, and it has long branched inflorescences. A. liliifolia is one of the orchids of this genus which has the widest range of all congeners, spread throughout most of Southeast Asia, Papua New Guinea, Australia, to the Solomon Islands.
Bogoria spp.
Orchids from this genus are monopodial epiphytic plants medium in size and prefer shady locations or with high light intensity. In Papua New Guinea, this orchid is often found attached to coastal forest trees, semi-deciduous forests, rainforests, and savannas at an altitude of about 0-600 meters above sea level. Orchids of this genus have stems measuring 10-20 cm long that grow dangling with the tip of the stem pointing upwards. The leaves also have a characteristic that is up to 35 cm long, 1.5-6 cm wide, rough, and dark green. Species that grow on trees jutting into the sea have purplish leaves. In this study, it was found that B. moorei with the local name of spotted orchid has ephemeral flowers that last only one day, fully bloomed, dangling, fragrant, cream to yellow in color with orange to brown spots, white labellum with purple and brownish orange spots, and the leaves are purple.
Bulbophyllum spp.
Asian tropical forests are central to the diversity of the genus Bulbophyllum with 1600 species occuring across the continent with New Guinea alone consists nearly 700 species. Bulbophyllum is known as an epiphytic orchid and has a creeping or hanging rhizome so that it can propagate in its growth. It has pseudobulbs that are ovoid to conical in shape which are sometimes covered by a midrib, and the petiole dangles with the tip turning upwards. Leaves are terminal, oblong to linear with a pointed tip, and inflorescences emerge from the base of the pseudobulb never from the apex.
Seven species of Bulbophyllum were found in our study, including B. baileyi, B. digoelense, B. fractifflexum, B. grandiflorum, B. macranthum, B. maxillare, and B. phalaenopsis. These orchids are all epiphytic with creeping rhizomes, sympodial with the placement of pseudobulbs have varying spacing on the rhizome. Variations of each species are found in the size of pseudobulbs, leaves, and flowers. B. baileyi flowers are cream to yellowish green, with red to purple spots with a characteristic fruity aroma. Characteristics of B. digoelense are flowers facing downwards, wide open, yellow or cream colored with purple stripes, and the very warty labellum has a dark purple color with a golden center. B. fractiflexum flowers are white or cream, barely open wide, sepals are white with yellow tips, petals are white, labellum is pale yellow, inflorescences are dangling, and the flowers last up to two weeks. The inflorescences of B. grandiflorum arise from the rhizome at the base of the pseudobulb with single, long-lasting flowers, brown sepals with white patches, dorsal sepals bent forward above the flower-like shields and lateral sepals wrinkled and hanging downwards, petals green with dark green stripes and purple spots, small white labellum with purple spots. B. macranthum sepals and petals cream, lateral sepals yellowish along the lower edge and red at the tips, sepals and middle petals with red spots, lateral sepals with red spots only along the upper edge, flowers with a sweet or spicy aroma, and shiny. Flowers of B. maxillare erect dorsal sepals are red to purple in color with white hairs at the edges, and lateral sepals are red and yellow or white in color downwards and usually join like a tail, small white petals with purple dots. While the uniqueness of B. phalaenopsis is that it has long and wide leaves with a size of 60 x 9 cm shaped like a purplish green tie, purplish green pseudobulbs, and purplish red flowers with yellow spots with yellow hairs.
Coelogyne spp.
This genus consists of more than 200 species with most of them being epiphytic plants that grow on large trees of primary forest. Coelogyne is distributed in parts of Southeast Asia and parts of the Oceanic islands such as the Maluku Islands, Solomon Islands and Papua New Guinea. Pseudobulbs are round to very flat and attached to the rhizome. The leaves are thick with sharp tips, oblong to lanceolate. Flowers vary in size, from small to large, but are generally pleasantly scented and short-lived. In this study, it was found that C. asperata had white or cream-colored flowers and the labellum was also white or cream-colored with orange-brown spots curved in the middle; pseudobulb ovoid, coarse-textured with two large green leaves on top; its roots enter the humus substrate or in a collection of ferns on tree branches
Dendrobium spp.
Dendrobium is one type of orchid that is widely cultivated for ornamental plants in pots and hanging plants, as well as used as cut flowers. The main attraction of Dendrobium as an ornamental plant is because of its flowers which consist of various colors, sizes and shapes, flowering throughout the year, long-lasting flower life of weeks and even months, and fragrant. This genus of orchids consists of about 1600 species of epiphytes with sympodial stems. The pseudobulbs are long, some are short, and have a fleshy or almost woody texture with oval to cylindrical shapes. The leaves are green, succulent, and sometimes fall. Subterminal or terminal inflorescences with flowers are usually small but attractive. Species of the genus Dendrobium found in this study reached 33 species, two of which are natural hybrids, namely D. antennatum x D. discolor and D. trilamellatum x D. canaliculatum.
Dendrobium antennatum x D. discolor is an unnamed natural hybrid found in the Yanggandur village of Merauke, very similar to an artificial hybrid that has been created from the same species and has been registered as Dendrobium “verninha”. This species prefers locations with full sun to semi-shady, living epiphytes with stems up to 1 m. It has thick leaves, oval in shape, and has uneven edges. Flower stalks arise from pseudobulbs with 15-20 flowers per raceme. Flowers measure about 40 mm high x 28 mm wide x 20 mm long. The sepals are twisted, bent, wavy edges and are white with thick purple stripes on all surfaces. Petals erect and twist two to three times, brown with purple veins and yellow edges. The labellum is large with a curved middle lobe with thick purple veins, and the side lobes are cream to yellow with purple veins.
Another natural hybrid is D. trilamellatum x D. canaliculatum, also an unknown species found in the Wasur village of Merauke. This natural hybrid occurs wherever the parents coexist, but is not common in various locations. This species is epiphytic and has pseudobulbs with purple veins when young. The leaves are 6-15 cm long, straight, thick, and fleshy. The flower stalk emerges from the tip of the pseudobulb and supports 6-20 flowers. The shape of the sepals and petals can be distinguished because the sepals are longer and narrower than the petals. However, both are crooked and predominantly brown in color. The flowering season of this orchid is from August to November.
Dendrochilum spp.
It grows as an epiphyte or lithophyte attached to rocks. This orchid likes a cool, semi-open and humid location in lowland forests to mountains with an altitude of 2600 meters above sea level. It has a rhizome that grows creeping and branching, nearby there are pseudobulbs of various shapes from oval to conical. Single leaves of various sizes, growing at the terminal stem, thin, with a pointed tip, leaf blade lanceolate to oblong. In this study, only one species was found, namely D. longifolium, which has a single flower, up to 30 cm long with 40-50 small transparent green flowers with a green-brown labellum. D. longifolium is the only species found in Papua but is not endemic and a common orchid found on the island.
Dipodium spp.
The genus Dipodium is a plant that grows as epiphytes, lithophytes, some saprophytes, and terrestrial. However, sometimes there are leafless ones (in lowland rainforests), and leafless Dipodium is still difficult to cultivate because it is unable to replicate associations with mycorrhizae. Members of this genus are usually tuber, experience dormancy for most of the year, and can flower when approaching summer producing 3-15 flowers. In this area, one species of Dipodium sp. was found but can not be identified until the species level. This species grows terrestrially, flowers are white with purple and maroon spots measuring 40-50 mm, blooms on brownish-green stems 40-120 cm long, and has no leaves. The dorsal sepals are 20-30 mm long and 4-6 mm wide, but the lateral sepals are slightly longer, and the petals are shorter than the two. The sepals and petals are not attached to each other and are slightly curved backward. The labellum is purple and has three lobes with a midline that is light purple in color. It blooms from November to March.
Geodorum spp.
It grows in small to medium-sized terrestrial areas in the rainforest, moist meadows to sandy areas near the coast with an altitude of 0-250 m above sea level. Has a partially buried oval to round pseudobulb. Experiencing dormancy in the dry season, shoots and leaves will appear in the rainy season, where the leaves will expand at the bottom to form new pseudobulbs. The stems are erect, slender, and have protective leaves. Leaves are thin and semi-folded with a pointed tip. One species was found in this study, namely G. densiflorum, which has pink flowers, only slightly opened, and curved towards the ground.
Grammatophyllum spp.
This genus has 13 species and is found naturally in Southeast Asia, Papua New Guinea, and Oceania. In Indonesia, this plant can be used as an ornamental plant and as medicine. The majority of members of this genus live as epiphytes, but some are found to be terrestrial, lithophytic, or saprophytic. One of the distinctive features of the Grammatophyllum genus is its roots which form a basket-like structure to accumulate nutrients. The pseudobulb is ovoid or cylindrical in shape. The leaves are hairless, have a cuticle, and have stomata on the upper surface of the leaf. In this study, two species were found, namely G. speciosum which is known as a giant orchid because of its large size, and G. scriptum which is an orchid endemic to Papua New Guinea.
Luisia spp.
This genus is spread from tropical Asia to Australia and is found at an altitude of 0-1700 masl, it lives as an altitude of 0-1700 masl, it lives as an epiphyte and loves open areas. The roots are very long, emerging from the base of the stem, and aerial roots are rare. The stems grow monopodial to medium size and will droop with increasing size. The leaves are straight teret-shaped green with a slight purple tinge at the base. In this study, one species was found, namely L. tristis which has green or yellow-green flowers with a dark maroon labellum with a velvety texture.
Nervilia spp.
The genus Nervilia has 65 species and lives terrestrially and is often used as medicine. It has spherical – elliptical bulbs and leaves that grow solitary with a heart shape or ovoid, sometimes there are feathers. Solitary terminal flowering emerges from the tuber. This plant is found in nature in the form of leaves only or flowers only with a short flowering period, making it difficult to perpetuate (Gale et al. 2007; Stern 2014). In this study, it was found that N. concolor had flowers that emerged from tubers in the soil, did not fully bloom, pale green sepals and petals, and white labellum with green or purplish veins and wavy; green leaves have brown spots, heart-shaped, pleated, tapered leaf tips, and wavy edges. Because of the unique leaf shape, many people do not know if the plant is a type of orchid. This species grows in the open, shady meadows, and under shady trees. Its distribution is widespread from India, China, Southeast Asia, Australia, to the Pacific Islands.
Oberonia aff. titania
It is an epiphytic orchid that grows on trees in groups to form clumps. The stems are very short with four to ten leaves per clump. It has small, lanceolate to lance-shaped leaves, fleshy, and overlapping leaf bases. It has very small and numerous, red flowers arranged in a circle and hanging. Most species of Oberonia are easy to cultivate, but they are less attractive because the flowers are not only small but also not bright in color. However, like other small-flowered orchids, if looked closely, it turns out to have beautiful flowers. This orchid can grow in various habitats, such as subtropical rainforests, mangrove forests, and Melaleuca swamps. This study found a species similar to Oberonia titania Lindl., but it is still uncertain whether it is a different species or a variation of this species.
Pachystoma spp.
There are 6 species of the Pachystoma genus which are widely distributed in India, Sri Lanka, Southeast Asia, Indochina, Papua New Guinea, Australia, to New Caledonia. However, only one species is widely distributed in Papua, namely P. pubescens. These orchids live terrestrial and have a dormant period. It has a cylindrical rhizome and a fleshy cylindrical pseudobulb that resembles a tuber. Leaves emerge from pseudobulbs numbering 1 or 2, thin, straight, erect with several midribs, 28 x 0.7 cm long, tapered ends, and leaves fall at the time of flowering. Inflorescences arise from the rhizome, erect, peduncle 40-55 cm long, there are 5 to 15 flowers. The sepals and petals are pale pink, the labellum is pale pink, the keel and the part between the keel are greenish yellow and the flower stalk is 0.2-0.3 cm long with velvety hair. It grows on high grasslands (usually alang-alang grass) in the lowlands and is subject to periodic fires. This periodic fire is one of the causes of the threat of extinction or habitat loss for P. pubescens.
Paphiopedilum spp.
This genus grows terrestrial and sometimes epiphytic, likes hot places and direct sunlight. Paphiopedilum lives in groups with 4-6 leaves that are linear to oblong, rounded tips and three-toothed, green, and there are few cilia at the base of the leaves. In this study, one species was found, namely P. glanduliferum which has yellow flowers and maroon veins, petals with maroon warts on the basal edge and usually twisted or twisted. The distinctive feature of this genus is the labellum which is shaped like a bag or sandal, yellow with brownish-purple veins. This species is found at an altitude of 0-200 masl and is one of the endemic species in New Guinea (Morales et al. 2018). This species is also a rare orchid that is included in the IUCN Red List in the endangered category and Appendix I CITES so its presence in nature must be of great concern.
Phalaenopsis spp.
One of the characteristics of this orchid is its flowers, which resemble moths. It lives as epiphytes at an altitude of 0-1500 masl. It has fleshy, fringed roots emerging from the base of the stem. There are 2-3 leaves that are wide, thick, leathery, and dark green with opposite leaves sitting. Flower stalks emerge from the base of the leaves which can reach 1 meter in length. This genus has beautiful flowers, but its growth in the wild is very slow. In early research, it was found that P. amboinensis had white flowers with thick brown or reddish-brown lines. This species is found only in eastern Indonesia, including Sulawesi, Maluku, Papua and Papua New Guinea, at low elevations in moist shady forests. In this research, P. amboinensis was no longer found, and only the P. amabilis orchid was found which had white flowers, yellow callus on the labellum, and on the yellow part, there were streaks with reddish spots. These orchids grow in a wide geographical range, both in the lowlands and highlands, and flower well in natural conditions.
Pholidota spp.
This plant grows to form a large clump. It has many roots that arise from the base of the pseudobulb. Pseudobulbs are pear-shaped to conical, smooth, and their young shoots are protected by brown bractea. A single leaf emerges from the pseudobulb, dark green to gray in color, stiff, thick, and pointed at the tip. In this study, it was found that P. imbricata has drooping flower stalks with small flowers in two opposite rows and there are 70-80 flower buds so that they form like a necklace. Flowers are about 7 mm long, white or cream with purple hues. Flowering year-round from January to November.
Phreatia spp.
It is an epiphytic orchid with monopodial stem growth. It grows in rainforests up to 800 m asl, mainly on the branches of large trees. It has a broad but short stem (almost no trunk) because it is hidden by overlapping leaf midribs and is surrounded by fleshy leaves. One species of this genus was found, namely P. micrantha. This species has 6-13 leaves arranged in a fan-like shape around the stem. Two slender and long flower stalks appear at once, then hundreds of white flowers measuring 2 mm bloom from base to tip and flowers bloom for 5-7 days. The flowering period can occur 2 to 3 times a year, namely April-May and August-December .
Pinalia spp.
The Pinalia genus contains 160 species ranging from the Himalayas to China, Indochina, Malesia, Australia and the Pacific. In this study, one species was found, namely P. fitzalanii which is easily found in forests near the coast and warm lowland forests from an altitude of 0-750 masl. It grows epiphytic or terrestrial and has rhizomes that are difficult to distinguish from pseudobulbs. Pseudobulbs are medium to large ovoid, green to brown in color, and have a sheath. Leaves grow from the tip of the pseudobulb as many as 2-4 strands, inverted ovate to elliptical with a pointed tip. Flower stalks that arise from the lower nodes of the leaves and grow 50 white to yellow and fragrant flowers.
Pomatocalpa spp.
Pomatocalpa is a genus of small to medium-sized epiphytic orchids with monopodial stem growth. Climbing stems can be short or long, measuring 50-90 cm, but are well-developed and stocky. The leaves are rope-shaped and at the base there is a sheath with a rough surface. Inflorescences appear laterally with many small and tightly arranged flowers. The habitat of this orchid is in lowland forest with an altitude of 0-700 meters. In New Guinea there are three species, but this study found one species, namely P. marsupiale which has yellow, greenish or yellow-brown flowers with red or brown spots; the labellum is cream or yellow in color and has large round sacs that sometimes have brown or red spots; the flowers are not always wide open and have a lemon scent. Usually grows well on tree trunks at low levels (up to 4 meters above the ground) in evergreen lowland forests.
Spathoglottis spp.
Grows terrestrially with sympodial stem growth and has a short rhizome. This genus has more than one segmented pseudobulb, some buried in the ground. Leaves arise from pseudobulbs, the base has a sheath, elongated and thin lanceolate. The inflorescence emerges laterally from the pseudobulb. This orchid likes open places in the lowlands. In Papua New Guinea, it is known that there are about 13 species, but in this study only two species were found, namely S. plicata and S. papuana. S. papuana is very similar to S. plicata, but S. papuana can be distinguished by the bare pseudobulb and fallen leaf base. In addition, the flower bractea is small and there are no hairs on the flower stalk, rachis (mother stalk) or ovaries.
Thrixspermum spp.
It grows as an epiphyte with monopodial and medium-sized stem growth. It has climbed or fringed stems with leaves spaced apart from one another. The leaves are flat, fleshy, and jointed. Lateral flower stalks, flower profusely, and sometimes several flowers open at once. In this study, two species were found, namely T. congestum and T. platystachys. T. platystachys has fleshy flowers that are yellow with a slight combination of white, the flowers only last one day and then wither (ephemeral). T. congestum is also ephemeral with cream to white, crystalline flowers, and sometimes brownish yellow with yellow-brown spots and the top and front of the labellum have short hairs, many of which are white.
Vanda spp.
In this study, one species of the genus Vanda was found, namely V. hindsii. This orchid is a large epiphyte with a leaf axis reaching 60 cm, growing upright but then curling. Monopodial stems 50 to 100 cm high. The leaves are arranged in two rows in the form of a ribbon with a length of up to 40 cm, dark green to yellowish green, shiny, rough, and incised ends. The flower stalk about 15 cm with 6-10 flowers measuring about 35 mm. Flowers are mostly shiny red-brown with yellow spots and olive-green edges. This species is native to Papua, Papua New Guinea, Queensland and the Solomon Islands.
Based on the results of this study, it can be concluded that there are 65 species of orchids in the forests of Merauke District belonging to 23 genera. Dendrobium became the genus with the most species found, namely 33 species. There were 10 endemic orchids, namely B. digoelense, B. phalaenopsis, D. devosianum, D. lasianthera, D. lineale, D. macfarlanei, D. poneroides, G. scriptum, P. glanduliferum, and S. papuana. In addition, there were 16 species listed in the IUCN with Last Concern status, 2 orchids in the Near Threatened category, and 1 orchid in the Endangered category, namely P. glanduliferum. All the species found in this study are listed in Appendix II CITES with one species listed in Appendix I, namely P. glanduliferum. This study shows that forests in Merauke are important natural orchid habitats. However, human activities can threaten the survival of the orchid in this area, including exploitation, conversion of land to settlements and plantations, as well as changes in the primary forest to secondary forest.