Download Hoya species diversity at Gunung Gede Pangrango

| 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
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3
4
5
6
8
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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
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-
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-
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-
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-
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.
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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