Species Orchid Society of
Western Australia (Inc)
ORCHID HABITATS OF NORTHERN THAILAND
By Ken Jones
Our first visit was to a Phu Hin Rongkla National Park in the Phitsanulok province, approx 300 km south east from Chiang Mai.
To get there, after loading all our luggage into a van, we travelled by railcar from Chaing Mai to Uttaradit. We were then picked then up by five vans that Peter Williams had hired for the tour - five for us (including two orchid enthusiasts from UK, and two from the Netherlands) and one for luggage. The first night we stayed in Sukothai before visiting the Sukothai Historic Park, and after lunch, travelled to the Rain Forest Resort. While some members found the steps up and down a little frustrating, the surroundings were very pleasant (although well away from any sizable town and shopping).
The next morning, we travelled to Phu Hin Rongkla National
Park for the first of our expeditions. After visiting a small on-site
museum which had many exhibits dating from the time of the Communist occupation
of the region, we watched film showing more of the history of the area.
The park, which covers 307 sq kilometres was designated in 1984 and lies
in the Phitsanulok and Loei provinces. In addition to orchids, there were
many Rhododendrons in the mixed deciduous, dry evergreen and hill evergreen
As the following photographs illustrate, the orchids were growing in a dry, evergreen low scrub area with frequent large rock outcrops. In some instances, these rocky areas were literally covered in orchids including Epigeneium amplum, Eria pannea, Doritis pulcherrima, Otochilus fuscus (sausage orchid), Thunia alba (or marshalliana), with many Bulbophyllum, Coelogyne, Eria and Luisia species that were not readily identifiable.
We also observed the effect of the drought that is presently affecting Northern Thailand. Some species growing in full sun were very red in colour, and very desiccated, particularly the small botanical species shown in the next photo which was living in the thin lichen layer on top of a large rock. This diminutive species had recently flowered and some we saw were carrying seed pods. We saw several plants of Doritis pulcherrima in similar positions looking extremely desiccated
Numerous leafless canes of Thunia alba (or marshalliana) that had flowered and were carrying up 3-5 large seed pods. These plants were growing in leaf litter and humus, but it was very noticeable that those in the open were less robust that those growing in shaded areas that probably retained some moisture or dew runoff.
A thicket of Thunia alba
In some cases, the canes of these latter plants were up to one metre tall and up to 4cm in diameter. Many had started to make new growth, even though there was little if any moisture available
Another interesting habitat observation was one that stood to reason, that is that species growing out in the open were generally quite different from those growing down in the ravines (that were often several metres deep and according to Peter Williams, sometimes held small streams even in the middle of the dry season). Looking down into these ravines, we were able to see large mats of orchids, principally Bulbophyllum, Drymoda, Rhytionanthos and Trias. Unfortunately, because we were not able to sight any of these plants in flower , it was impossible to positively identify any species.
Some of the group made their way to a lookout over
a high cliff, while most of worked our way through the rock field.
After a late lunch, we headed back to the vans and drove back to Rain Forest Resort. After a shower, several of us walked up to the nearby waterfall and across a very rickety suspension bridge, made all the more existing by the motor bikes being ridden across by locals (who probably wondered what we were doing there), and then wandered up for dinner at about 7.00pm.
The pathway to our room.
Part Two of this article covers the last few days of our orchid tour in Northern Thailand. As I mentioned in part 1, Northern Thailand is in drought and the in situ orchids species that we observed were shrivelled and often quite blackened, but is many cases were flowering despite this adverse treatment. On Sunday 21 March, we left the Rainforest Resort and drove for a few hours to the lowland Namnao National Park
I recall thinking that we would probably see different orchids given the altitude, and the number of orchid plants in flower at the park headquarters. However, the trek itself was disappointing with relatively few orchids sighted and even less in flower. The forest was heavily invaded by bamboo, and there were few large trees- these often had orchid plants on horizontal limbs but even with binoculars, it was difficult to identify orchid plants.
After leaving this park, we stopped briefly at dry stream bed where Peter Williams had previously seen Paphiopedilum concolor growing in an overhanging earth bank.
After a short walk to the steam, we walked up the bed and Peter pointed out a solitary plant (which was not in flower). While walking along this stream bed, we saw numerous bamboo stems that had been cut at an angle on one end that are used to remove orchids, including the rest of the Paphiopedilum concolor that Peter had seen some years earlier.
This particular plant appeared to be a more difficult position to remove and so was still in-situ, although it was difficult to be confident that if we went back, it would still be there. There is an active trade in wild-collected plants.
We saw several species in this immediate vicinity, and spent some time trying to identify them. Ultimately, I thought that the species pictured below could be an albinistic form of Dendrobium draconis, although there is an albinistic form of Dendrobium lituiflorum but cannot be sure.
We also saw plants of Chilochista that had fallen from its place on a tree branch, Pomatocalpa spiccata (the flowers had been pollinated and were forming seed pods), and several other botanical species, none of which were in flower.
After spending a hour or so walking up the stream bed, we returned to the vans and headed for our next destination, Loei. Loei is a large town, located in North-eastern Thailand, approximately 40 km from the border of Laos.
We stayed at three star hotel, which while comfortable, principally catered for local business travellers. Consequently, it lacked some of the facilities which we might normally expect, for example, the restaurant which was located off the entry foyer was not part of the hotel, but a separate business. They had difficulty coping with the influx of some 34 guests on the first night after Loei was drenched by a sudden thunder storm not long after we arrived. Naturally, most were less than enthusiastic about heading out for dinner (in fact some had to cope with rain coming through the roof into their rooms!)
The following day, we set out for a highland wildlife sanctuary that Peter has been visiting for several years. During this time, he has developed a relationship with one of senior rangers who has a good knowledge of where the best orchids are located. As this park does not have any food stalls (other than for its workers) we stopped to buy something for lunch on the way. While the choice was limited, none of us starved!
After travelling for about 45 minutes,
we arrived at the park entry and after Peter negotiated the fee, we travelled
for another 45 minutes up a steep, winding road through primary forest
to the Ranger station on a high plateau (1,450m above sea level).
As had been carried out at the previous park, many orchids had been attached to trees around the ranger station. Peter mentioned that probably some of these were plants that had been seized from people who had removed them to sell at the local markets.
In this area alone, we saw many species in flower including Bulbophyllum, Coelogyne, Cymbidium, Dendrobium, Eria, Sunipia and Vanda.
The habitat on the plateau consisted of occasional large trees, but was primarily low evergreen scrub containing large stands of tropical Rhododendron.
While the habitat was dry (even though it had rained the previous evening) we saw the effect of the drought as many of the orchids were shrivelled and showing signs of stress. We also saw many orchids with seed pods indicating the pollinator population is active and in good health.
In Part 4 I will
take this opportunity to show a few more photos from our Thailand Trip
from the excellent CD that Tony has produced. As I did in the earlier
parts of this article, I will focus on habitat and what it can teach us
about growing our species orchids better.
As you can see, the roots which are anchoring the plant to the tree are fully exposed to the sun, and wrap around the tree holding the plan firmly in place. In the first of these photos, it shares its host with a Dieffenbachia or Pothos.
While not prolific like some of the other species, we observed two of three places where quite large mats of plants were living, often in a leaf mulch-filled crack in the rocks. Perhaps this traps moisture from dew. The silvery leaves were covered with fine fuzzy hairs (similar to some of the arid succulent plants where the leaf colour and hairy surface act to minimise the effects of an adverse climate).
On closer examination, some of the roots had made their way into small cracks in the rocks where presumably like the Eria pannea, they benefited from being cooler and accessing moisture. However, most of the active roots (ie those with green tips) were purely aerial, while those on exposed rock were anchoring the plant. With its terete leaves, this species is well adapted to living in high exposure locations.
As you will see in the photo, the roots are firmly locating the plants - in the second photo, they are encircling the tree branch. The extended flower racemes show that these plants have been flowering for a long time - perhaps several years. While not as vigorous as those grown by members like Tony, Peter and Maxine, clearly these plants are getting enough nutrient to grow and flower. Their choice of habitat suggests that they would be quite happy on mounts.
As a finale to this article, I will take a final look at some more of Tony's photos from the recent Thailand trip, and some from our visit to Vietnam in 2008.
What was more surprising however was while some plants carried seed pods, we saw few juvenile plants on the same tree as the parents. Similarly, not every tree carried plants of Dendrobium bellatulum, although in some cases there were also large mats of Bulbophyllum species.