Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
| Proc Soc Indon Biodiv Intl Conf | vol. 1 | pp. 77-81 | July 2012 | ISSN 2252-617X | Hoya species diversity at Gunung Gede Pangrango National Park, West Java, Indonesia SRI RAHAYU Bogor Botanical Gardens, Indonesian Institute of Sciences. Jl. Ir. H. Juanda 13 Bogor 16911, West Java, Indonesia. Tel. +62-251-8322187 Fax. +62-2518322187. email: [email protected] Manuscript received: 18 July 2011. Revision accepted: 5 July 2012. Rahayu S. 2012. Hoya species diversity at Gunung Gede Pangrango National Park, West Java, Indonesia. Proc Soc Indon Biodiv Intl Conf 1: 77-81. A survey on the diversity of Hoya (Asclepiadaceae) species was conducted at Gunung Gede Pangrango National Park. The survey conducted in May-July 2008 at the different altitude from four locations. There were found ten Hoya species grows in the elevation between 650 and 1500 m. Two species are only found at elevation above 1000 m, while the other eight grow well below 1000 m. The inventory also suggests that the existence of H. forbesii King & Gamble, H. micrantha and H. imperialis Lindley and are new records for the Java Island. The highest diversity was found at the Bodogol Research Station, which have lowest elevation at 650-900 m. Reinventory for the Java Island is needed. One of the most required works is for the Gunung Gede Pangrango National Park-West Java. Gunung Gede Pangrango National Park has been stated as Biosphere reserve and the area has been extended recently to the lowland area below 1000 m above sea level (asl). There are only two Hoya species recorded from this former location (Rugayah and Sunaryo 1992) at elevation above 1000 m asl. As assumed Hoya species diversity is higher at the low elevation (Rintz 1980; Schlechter 1914), the inventory was focused especially on the new extended area of the lowland forest below 1000 m asl. Hoya, Asclepiadaceae, species diversity, reinventory, Gede Pangrango National Park MATERIALS AND METHODS The popularity of Hoyas (Hoya spp.: Asclepiadaceae) has been increased particularly as exotic ornamental plants in Europe, USA and Australia (Wanntorp et al. 2006). It can be proved by the increasing numbers of Hoya web pages and the Association of dedicated on Hoya horticulture, international trades and plant exchanges (Hodgkiss 2007). Hoyas are also used as the important medicines by the indigenous people who live near the forest (Zachos 1998). The increasing uses and popularity will imply on the demand and may cause increasing harvest from the wild that in turn will decrease the species occurrence in nature. As an epiphytic plant, Hoyas have been important to the tropic. Epiphytic plants most abundant in the tropic (Zotz 2005) and also known as a typical feature in tropical forest (Ghazoul and Sheil 2010). Indonesia has been predicted to have the highest Hoya species diversity in the world (Goyder 2008; Kleijn and van Donkelaar 2001). But the inventory of the species in this location still limited. Inventory of the species richness is one of the main priority because (i) available data limited and out of date: (Miquel, 1856: Indonesia (Netherland Indie), Koorders (1898: Minahasa-North Sulawesi, Backer & Bakhuizen v.d. Brink Jr. (1965: Java Island; (ii) the rapid habitat lost and degradation (iii) updating data on the geographic perspective. The recent preliminary inventory on the Indonesia’s Hoya have been done (Rahayu 1999) based on the result of The Bogor Botanical Gardens’ botanical exploration; continued by the inventory for the Hoya of Sumatera (Rahayu 2001) and from Bukit Batikap, Central Kalimantan (Rahayu 2006). Inventory to the occurrence of Hoya species at Gunung Gede Pangrango National Park was done by belt transects observation (Cox 2002) vertically from below to the top of mountain at different elevation, from 650 to 2000 m a.s.l. The sampling was done at four different sites (research stations) as follows: (i) Cibodas (1400 m a.s.l.); (ii) Bodogol (650 m a.s.l.); (iii) Situ Gunung (1000 m a.s.l.); and Cugenang/Gedeh (900-1500 m a.s.l). All of the Hoya species occurrence were recorded and collected as herbarium specimen and living collection for the Bogor Botanical Gardens. Data passport collected along with the specimens are as standard for herbarium specimen. The specimens identified by using several description published on hoyas and compared with the type specimens at BO or electronically. RESULTS AND DISCUSSION Identification Hoya Description. Hoya R.Br., Mem. Wern. Nat. Hist. Soc. 1: 26. 1811, prepr. 1810; Hooker, FBI 4: 52. 1885; Constantin, Fl. Gen. Indo-Chine 4 : 125. 1912; Ridley, Fl. Malay Pen. 2: 393. 1923; Backer & Bakh. v.d. Brink f., Fl. Java 2: 266. 1965; Type species: Hoya carnosa R.Br. in Trans, wern. Soc. I. P. 27 Plants epiphytic, epilithic, rarely rooting in the ground, creeping, climbing, pendent, left-twining, rarely shrubby, latex white, rarely clear. Root fibrous. Stem terete, sparsely branched, glabrous to pubescent. Leaves decussate, alternate at seeding stage, rarely imbricate, petilolate, 78 Proc Soc Indon Biodiv Intl Conf 1: 77-81, July 2012 lamina lanceolate to obcordate, entire, leathery, fleshy to succulent. Inflorescence racemose, occasionally with part inflorescence, lateral or rarely terminal, 1-to many flowered, globose, flat or concave, rarely with a peduncle > 10 cm long. Flower 5-merous, actinomorphic. Pedicel uniform and straight or length variable within an inflorescence and bent. Corolla star shaped and spreading, campanulate or almost broadly urceolate, outside glabrous, inside rarely glabrous, recurved or reflexed wax-like, fleshy. Corona 5, fleshy and waxy, horizontal or not, sometime have 2 color. Pollinia 5 pairs, each pairs on a corpusculum, pollinia shape elliptic to oblong. Fruit follicle terete, acuminate, smooth. Seeds comose, ovate or linear oblong; coma 1-3 cm long, white or broken white. Key to Hoya at Gede Pangrango National Park (GPNP) There are 10 Hoya species found from this study with the key to the species as below: 1.a. Stem twining ………………………………….……….. b. Stem non twining ……..……………… 8. H. multiflora 2. a. leaves thin and chartaceous …………..………….…… b. leaves thick or fleshy …………………… ……..………. 3.a. the upper surface of leaves glossy, corolla star shaped …………………………….…… . 2. H. coriacea b. the upper surface of leaves dull, corolla campanulate … …………....................……………… 1. H. campanulata 4.a. leaves thick, not fleshy, pubescent ……..3. H. imperialis b. leaves fleshy, glabrous ……….………………………… 5.a. leaves narrow (1-3 cm width), corolla revolute ……… b. leaves wide (3-10 cm width), corolla star shaped ……. 6.a. leaf margin revolute, pedicel 0.2-5 cm long …… ........………………………………...…. 7. H. micrantha b. leaf margin not revolute, pedicel 0,5-2 cm long ...…. 7 7.a. leaf venation invisible, corolla dark or light brown ……………………………………………... 4. H. kuhlii b. leaf venation visible, corolla creamy white ………… …………………………………...…..…. 5. H. lacunosa 8.a. leaves oblong ……………………… 10. H. vitellinoides b. leaves cordate ……………………… …………………. 9.a. Inflorescence multipeduncled at a node, corolla 0.8 cm diam …..…........................................…... 6.H. latifolia b. Inflorescence single peduncled at a node, corolla 1,5 cm diam ................................................. 9.H. purpureofusca 2 3 4 5 6 8 9 Species description Hoya campanulata Blume (Bijd. (1826): 1064.; Rintz, Malay. Nat. J. 30 (1978): 495. Fig. 13). Type: Java (L!) (Figure 1a) Syn: Physostelma campanulatum (Bl.) Decne., DC. Prod. VIII, 633;Stem finely hirsute with glabrous floriferous branches c. 30 cm long. Leaves thin and chartaceous, elliptical, up to 12 cm long by 6 cm wide. Peduncle reflexed, rigid, 1-6 cm long; Umbel convex with flexuous uniform pedicels 4-5 cm long, 1-30 flowers, open 8 days. Corolla campanulate, nearly glabrous inside, up to 2.5 cm diameter by 1.5 cm deep, creamy white. Corona white or cream, occasionally with a deep red stripe on the upper lobe. Follicle c. 16 cm long by 7 mm diam; dark green striped. Locality: Bodogol Research Station Distribution: India, Malay Peninsula, Sumatra, Java, Borneo Habitat and Ecology: along riverside at 650 m asl Notes: Hoya campanulata is characterized by the thin leaves and campanulate corollas H. coriacea Blume (Bijdr. (1826): 1064; Rintz, Malay.Nat. J. 30 (1978) 495, Fig.13). (Figure 1b) Type: not seen Easily confused with H. campanulata vegetatively, but more robust and without short, floriferous branches. Stem glabrous, leaves thick and chartaceous, elliptical, up to 12 cm long by 6 cm wide, glossy at upper surface. Peduncle reflexed rigid up to 8 cm long, Umbel convex with rigid unformed pedicels 4-5 cm long. 1-40 flowers, open 4 days. Corolla densely tomentose with long yellow hairs, c. 1,5 cm diam. Corona upper lobe purple, lower lobe white. Follicle c. 12 cm long by 1.5 cm diam. Locality: Bodogol Research Station Distribution. Malay. Peninsula, Borneo, Java, Thailand, India Habitat and Ecology. Slopes, open areas Notes: Hoya coriacea is characterized by the thick, not fleshy coriaceous leaves Hoya imperialis Lindley (Bot. Reg. t. 68 (1846); Rintz, Malay. Nat. J. 30 (1978) 501, Fig. 18). Type: Borneo (?) (K). (Figure 1c) Stems very thick and smooth, c. 8 mm diam. Leaves fleshy, oblong with obtuse or shallowly cordate bases; up to 16 cm long by 5-6 cm wide. Inflorescences: Peduncle pendant, 10-12 cm long. Umbel convex with flexuous, uniform pedicels c. 8 cm long, 1-10 flowers. Corolla lobes spreading, fleshy, very finely pubescent inside; 3-5 cm diam; deep red. Corona blunt and massive, upper lobe with a conical process; entirely yellow or creamy. Corpuscle wide, clavate. Follicle c. 23 cm long by 2.5 cm diam. Locality: Bodogol Research Station Distribution: Sumatra, Malay Peninsula, Borneo, Philippines Habitat and Ecology: slopes, semi open areas Notes: Hoya imperialis is characterized by its large flowers (3-5 cm diam). Hoya kuhlii Blume (Bijr. (1862)); Type: Java, Blume s.n. (L!). (Figure 1d) Leaves fleshy, elliptical with long attenuate bases and rigid margins up to 8 cm long by 4 cm wide. Peduncle reflexed, rigid, 5-10 cm long. Umbel concave with rigid curved pedicels 5mm-3 cm long, 1-25 flowers. Corolla revolute outward, pubescent inside c. 8 mm diam, pale or dark brown, corona red at center. Locality: Cibodas Distribution: Java Habitat and Ecology: mountain forest . Notes: Hoya kuhlii is characterized by the small size and brownish revolute corollas Hoya lacunosa Blume (Bijr. (1826) 1063; Rintz, Malay. Nat. J. 30 (1978) Type: Java, Blume s.n. (L!). (Figure 1e) Stems thin. Leaves fleshy, of two forms, one form ovate, thick, up to 3 cm long by 2.5 cm wide the other form RAHAYU – Hoya of Mount Gede-Pangrango National Park, West Java 79 oblanceolate up to 7 cm long by 3 cm wide, margin ridged. Peduncle reflexed, rigid, up to 5 cm long. Umbel concave with rids curved pedicels c. 5 mm-2,5 cm long, 1-30 flowers, open 4 days. Corolla revolute outward, pubescent inside with long thick hairs, c. 8 mm diam, white. Corona lower lobe upcurved, solid, both lobes white. Follicle 5-6 cm long by 5 mm diam. Locality: Gedeh/Cugenang; Bodogol Research Station Distribution: Sumatra, Malay Peninsula, Borneo, Thailand, Java Habitat and Ecology: common in lowland and hill forest especially along rivers. Notes: Hoya lacunosa is characterized by the small leaves and small white revolute flowers Corolla finely pubescent inside, lobes strongly reflexed, c. 2cm diam, white with pale orange tips and occasionally with scattered pale purple spots. Corona stalked, with long reflexed lower lobes, both lobes white. Anthers deep purple. Follicle c. 20 cm long by 6 mm diam. Locality: Bodogol Research Station Distribution: Sumatra, Malay Peninsula, Borneo, Philippines Habitat and Ecology: common but not abundant, many encountered on ridges between 700-900 m asl. Notes: Hoya multiflora is characterized by the arrowhead shaped flowers. There was morphological variation according to various habitat types at Bodogol (Rahayu et al. 2010a) Hoya latifolia G. Don. (Gen.Hist..Pl. IV (1838) 127; Rintz,Malay. Nat. J. 30 (1978) 508.511. Fig. 23 Type: (?). Type: not seen. (Figure 1f). Stem deep red when young. Leaves fleshy, ovate with cordate bases and with a pair of veins parallel to the midrib; up to 25 cm long by 15 cm wide; upper surface glossy green, pale green or red below. Inflorescences multipeduncle, peduncle produced successively on paired racemes 3-6 cm long. Umbel convex with rigid uniform pedicels c. 2 cm long, 1-40 flowered. Corolla spreading, finely pubescent inside, c. 8 mm diam, pale pink or brown outside, creamy inside, Corona white with pink in the centre. Locality: Gedeh/Cugenang; Bodogol Research Station Distribution: Sumatra, Malay Peninsula, Borneo, Java, S Thailand Habitat and Ecology: twining on large tree especially along the river Notes: Hoya latifolia is characterized by the multipeducled inflorescences Hoya purpureo-fusca Hooker (CBM 76: t. 4520+text, 1850). Backer & Bakh.vdBrink Fl. Java II (1965) T: Java (Loob s.n. [K!]. (Figure 1i) Stems terete, glabrous; Leaves: petiole c. 15 mm long, very thick, brownish, lamina ovate, 10-12.5 x 7.5-10 cm, fleshy, acute to acuminate, base rounded; Inflorescence many flowered semi globose; peduncle up to 8 cm long, pedicel thin uniform 2 cm long. Corolla c. 1.5 cm diam., dark pink to dark purple, inside glabrous or pubescent to villose, margin slightly involute; Corona flat, lobes ovate, acute, dark pink to strongly purple-brown, upper surface keeled and depressed in the middle, lower face convex. Locality: Cibodas, Situgunung Distribution: Sumatra, Malay Peninsula, Borneo, Philippines Habitat and Ecology: wet and shade area Notes: Hoya purpureofusca is characterized by the purple color of corolla and corona. Hoya micrantha Wight ex Hooker fil. (Fl. Brit. Ind 4: 55. 1883). (Figure 1g) Type (lecto): Malaysia, Malacca (Maingay 1127 [K!]) Stem twining, terete, thin, glabrous; Leaves petiole thick, 4 mm long, lamina elliptic, 8x4 cm, glabrous, acuminate, base acuminate, margin strongly revolute; Inflorescence 1-30 flowered, concave, pendent; peduncle to 5 cm, rigid; pedicel 0.2-5 cm, strongly bent; Corolla 5 mm diam, pale pink, inside finely weakly pubescent, lobes triangular, strong revolute outward, Corona lobes elliptic, outer appendage bifid, white or pale pink, inner appendage acuminate, ascending, deep red, whitish or pale pink; Locality: Bodogol Research Station Distribution: S Burma to Thailand, Malay Peninsula Habitat and Ecology: slopes, semi open area. Notes: Hoya micrantha is characterized by the small and orange revolute corollas Hoya multiflora Blume (Bijr. (1826) 1063; Rintz, Malay. Nat. J. 30 (1978)Type: Java, Blume s.n. (L!). (Figure 1h) Stem non twining with branches only at the base, up to 2 m long, leaves chartaceous, elliptical, apically cuspidate, up to 18 cm long by 3-7 cm wide. Peduncle reflexed, rigid, up to 5 cm long. Umbel convex with flexuous uniform pedicels 4-7 cm long, 1-40 flowered, open 5-7 days. Hoya vitellinoides Bakh.f. (Blumea 6(2):381(1950); Backer & Bakh.f., Fl. of Java II (1965):269. (Figure 1j) Type: Java, West, Ciampea, Mt. Tjiputih, alt. 800 m, Bakh 4181 (L, isotype: BO!) Leaves tick, broadly oblong up to 16 cm long by 6.5 cm wide, venation reticulate darker than the background at the upper surface. Inflorescences: Peduncle horizontal, rigid, 25 cm long. Umble: uniform pedicel c. 2 cm long;1-20 flowers, corolla spreading, finely and sparsley pubescent inside and out; c. 1 cm diam; pale green or yellow. Corona entirely white. Locality: Bodogol Research Station Distribution : Java (rare), Sumatra at high elevation Habitat and Ecology: river bank, humid and shade area Notes: Hoya vitellinoides is characterized by the darker venation at the upper surface of leaves. Altitudinal distribution and habitat diversity Rintz (1980) and Schlechter (1914) assumed that most Hoya species occur at low altitude as reflected in this study. Out of ten species occurred from this study, eight of them were found at elevation of below 1000 m. Only two species i.e. Hoya purpureofusca Hook.f and Hoya kuhlii Blume found at elevation of above 1000 m. Beside of altitudinal distribution, the occurrence of the species depends on the habitat types which refer to the humidity such as river bank, slope, or top hill (Table 1). 80 Proc Soc Indon Biodiv Intl Conf 1: 77-81, July 2012 A B E C G F D H Figure 1. A. H. campanulata Blume; B. H. coriacea Blume; C. H. forbesii King & Gamble; D. H. imperialis Lindley; E. H.kuhlii Blume; F. H. lacunosa Blume; G. H. micrantha Wight; H. H. latifolia G.Don; I. H. purpureofusca Hook.f. Table 1. Hoya species distribution at Gunung Gede Pangrango National Park at different altitude and habitat Top Hill River Bank Slope Top Hill H. campanulata Blume H. coriacea Blume H. imperialis Lindle H. kuhlii Blume H. lacunosa Blume H. latifolia G. Don H. micrantha Wight ex Hook.f. H. multiflora Blume H. purpureo-fusca Hook.f. H. vitellinoides Bakh.f. Slope Species Alt 1000-1500 River Bank Alt 1 <1000 - - - - Discussion There were ten species found at the Gunung Gede Pangrango National Park resulted from this study. Two of them were new records for Java, i.e. Hoya imperialis Lindley and Hoya micrantha Hook.f. H. imperialis Lindley was formerly known in Sumatra, Borneo, Malay Peninsula and the Philippine (Rintz 1978). This is an interesting species with the large red flowers. H. micrantha was formerly known at Burma, Thailand and Malay Peninsula (Rintz 1978; Thaitong 1996). According to Rahayu (2001) who observed herbarium at BO, this species also found in Sumatra. The two new records were not mentioned in Flora of Java (Backer and Brink Jr 1965). This new records may result from the new geographic distribution of the species from Sumatra, as Hoya species have been known as having plumed parachute like seed and mainly dispersed by wind (Armstrong 1999; Rahayu and Sutrisno 2007). Rahayu et al. (2010b) concluded that there are two ways of Hoya seed dispersal by wind, i.e. long distance and short distance dispersal which depends on the wind type (speed and direction). This is a remarkable result as there were only two species known before at Gunung Gede Pangrango National Park (Rugayah and Sunaryo 1992). Most of the new finding was from Bodogol resort at elevation of 650-800 m, including three new records for Java. The Bodogol resort is the only area of the Gunung Gede Pangrango National Park which is situated at low elevation (below 1000 m). The area is result from the GGPNP extension in 2003 (Balai Taman Nasional Gunung Gede Pangrango official, personal communication). Extended area at lower elevation below 1000 m resulted more species diversity and of course the number of species protected will increase. The distribution of epiphyte depends on the dispersal affectivity and habitat quality (Lobel and Rydin 2009). There was separation in species distribution according to elevation. Two species, H. purpureofusca and H. kuhlii were only found at elevation of above 1000 m in Cibodas, Situgunung and Gunung Putri. While the eight others species were not found at above 1000 m. This is as result of plant reaction to the temperature zone as mentioned by van Steenis (1972, 2006) in his thermo-ecology schematic concept. In this concept, plant has been divided into three groups i.e. megaterm, mesoterm and microterm. The megaterm plant capable to develop in warm condition and concentrated at the equator line/zone and only found at low elevation of tropical region. Mesoterm plant well developed in a cool condition. This plant concentrated at the meso RAHAYU – Hoya of Mount Gede-Pangrango National Park, West Java 81 latitude or mountain area of tropical region. Microterm plant best developed at the high latitude and high elevation of tropical region which have cold temperature. This ecological preference is genetically base and constant during the evolution processes. In the tropical region, megaterm occurs at elevation of below 1000 m (colline zone), mesoterm at elevation of between 1000-2400 m (sub montane and montane zone) and microterm at above 2500 m (sub alpine and alpine zone). The heterogeneity of the habitat presumably influences the distribution of epiphytes. According to Winkler et al. (2005), the heterogeneity of habitat affected seedling success but not germination percentage. As epiphytic plants, most of Hoya species love humidity. This is as consequences do to their home at the aerial zone can be categorized as an arid environment. Humidity related to the stressor. The major factors which limit epiphytic life and thus may become stressors are light, water and mineral nutrition (Benzing 2008; Lutge 2008). According to Zotz and Heitz (2001) water is the main factor affected to growth of epiphytes. Most of them will be easily found at the riverside or any humid places. H. campanulata, H. lacunosa, H. latifolia, H. forbesii, H. kuhlii and H. purpureofusca have been found at the humid places. While H. coriacea, H. imperialis and H. micrantha found at slopes of hill in open and semi open areas. Armstrong WP. 1999. Blowing in the wind: seed & fruit dispersal by wind. Wayne's Word Noteworthy Plants. www.waynesword.palomar.edu/ plfeb99.htm Backer CA, Bakhuizen v.d. Brink Jr RC. 1965. Flora of Java. Vol. II. Noordrof, Groningen. Bakhuizen v.d. Brink Jr RC, Backer CA. 1950. Notes on the flora of Java.VI. Asclepiadaceae. Blumea 6 (2): 368-382 Benzing DH. 2008. Vascular epiphytes. Cambridge Univ. Press, Cambridge Blume C. 1826. Bijdragen flora Nedherlands Indie: 1064. Netherland Brown R. 1810. On the Asclepiadaceae, a natural order of plants separated from the Apocinae of Jussieu. Mem. Wern. Nat. Hist. Soc. 1: 15-58 Constantin J. 1912. Asclepiadacees. In: Masson C, et al (eds), Flore Generale de L’Indo-Chine. Tome Quatrieme, Paris Cox GW. 2002. General ecology laboratory manual. McGraw Hill, New York Don G. 1838. A general history of the dichlamydeous plants IV. London Ghazoul J, Sheil D. 2010. Tropical rain forest ecology, diversity and conservation. Oxford: Oxford Univ. Press Goyder D. 2008. Hoya multiflora Blume (Asclepiadaceae).Curtis’s Bot. Magazine 7 (1):3-6 Hodgkiss J. 2007. The Hoya society international. www.graylab.ac.uk/ usr/hodgkiss/ hoya1.html Hooker JD. 1850. Companion to the botanical magazine. London Hooker JD. 1885. Flora of British India. Vol. IV. L. Reeve & Co., Ltd., London. Kleijn D, van Donkelaar R. 2001. Notes on the taxonomy and ecology of the genus Hoya (Asclepiadaceae) in Central Sulawesi. Blumea 46: 457-483. Koorders SH. 1898. Flora van N.O. Celebes. s'Gravenhage G. Kolff & Co., Batavia Lindley J. 1846. Botanical register; consisting of coloured figures of exotic plants cultivated in British gardens; with their history and mode of treatment. London Löbel S, Rydin H. 2009. Dispersal and life history strategies in epiphyte metacommunities: alternative solutions to survival in patchy, dynamic landscapes. Oecologia 161(3):569-579 Lüttge U. 2008. Physiological ecology of tropical plants. Second Edition. Berlin: Springer-Verlag Merrill ED. 1923. An enumeration of Philippines flowering plants. Vol. III. Bureau of Printing, Manila Miquel J. 1856. Flora van Netherlandsch Indie. Tweede deel. Fried Fleischer, Liepzig Rahayu S, Sutrisno. 2007. Potency of Hoya seed in propagation and conservation: case study on Hoya parasitica Wall. Buletin Kebun Raya10 (2) : 33-39 [Indonesian] Rahayu S. 2006. Species diversity of Hoya in Bukit Batikap, Muler Mountain, Central Kalimantan. Biodiversitas 7(2): 139-142 [Indonesian] Rahayu S, Jusuf M, Suharsono, Abdulhadi R, Kusmana C. 2010a. Morphological variation of Hoya multiflora Blume at different habitat type of Bodogol research station of Gunung Gede Pangrango National Park, Indonesia. Biodiversitas 11 (4): 187-193 Rahayu S, Kusmana C, Abdulhadi R, Jusuf M, Suharsono (2010b) Distribution of Hoya multiflora Blume at Gunung Gede Pangrango National Park, Indonesia. J For Res 7 (1): 42-52 Rahayu S. 1999. Eksplorasi dan pembudidayaan Hoya (Asclepiadaceae) dalam rangka konservasi plasma nutfah. Prosiding Seminar Nasional Konservasi Flora Nusantara (Bogor, 2-3 Jli 1997). UPT BP Kebun RayaLIPI, Bogor. [Indonesia] Rahayu S. 2001. Genetic diversity of Hoya from Sumatra. [MSc.Thesis]. Bogor Agricultural University, Bogor. [Indonesian] Rintz RE. 1978. The Peninsular Malaysian Species of Hoya (Asclepiadaceae). Malay Nat J 30 (3/4): 467-522. Rintz RE. 1980. The biology and cultivation of Hoyas. Asclepiadaceae 19: 9-17 Rugayah, Sunaryo. 1992. Flora Taman Nasional Gede Pangrango. Herbarium Bogoriense, Bogor [Indonesia] Schlechter FRR. 1914. Die Asclepiadaceen von Deutsch-Neu-Guinea. Translated by D. Kloppenburg, Fresno, USA Thaitong O. 1996. The Genus Hoya in Thailand. In: The Taxonomy and Phytochemistry of the Asian Asclepiadaceae in Tropical Asia. Proc of Botany 2000 ASIA Intl Seminar and Workshop. The Herbarium Dept. of Biology, UPM and BOTANY 2000 ASIA, Selangor, Malaysia. Van Steenis CGGJ. 1972. The Mountain Flora of Java. EJ Brill, Leiden. Van Steenis CGGJ. 2006. Flora Pegunungan Jawa. Indonesian edition of The Mountain Flora of Java. Translated by Kartawinata JA. Pusat Penelitian Biologi LIPI, Bogor [Indonesia] Wanntorp L, Koycan A, Renner S. 2006. Wax plants disentangled: A phylogeny of Hoya (Marsdenieae, Apocynaceae) inferred from nuclear and chloroplast DNA sequences. Mol Phylogenet Evol 39: 722-733 Winkler M, Hulber K, Hietz P. 2005. Effect of canopy position on germination and seedling survival of epiphytic Bromeliads in a Mexican humid montane forest. Ann Bot 95: 1039-1047 Zachos E. 1998. Practical uses of various Hoya species. The Hoyan 19 (4)/20 (1): part II: 6-10/3-8 Zotz G. 2005. Vascular epiphytes in the temperate zones: a review. Plant Ecol 176: 173-183 Zotz G, Hietz P. 2001. The physiological ecology of vascular epiphytes: current knowledge, open questions. J Exp Bot 52: 20672078. Conclusion. According to this research, ten species were found at GGPNP. Increasing number from two to ten was mainly caused by the extension of the National Park area to lowland forest. Most species diversity was found at lowland forest (below 1000 m asl), at Bodogol. Two new records for Java were found, i.e. Hoya imperialis Lindley and Hoya micrantha Wight ex Hook. f