How does your garden grow?
By Eric Danell, Dokmai Garden
A Cartoon bumblebee
It looks like a cartoon bumblebee – how
else can I describe the flower of
Aerides odorata (Orchidaceae)? It is thick and fleshy, the
petals and sepals (spare the fleshy lip) all resemble wings and they are
elegantly held in one plane. The spur really accentuates the shape of a
wasp, being prominent and pointing forward. The flowers are white and pink,
like small scoops of strawberry ice cream. t is native from the Himalayas to
most of Southeast Asia and prefers a sunny position up in a tree, which is
why a deciduous tree is a good choice in a Chiang Mai garden.
lobes of the lip are really tall, making the lip look swollen. The beak-like
column reveals it is an orchid of the Aerides genus. It is in fact the type
species on which the scientific genus description was made. The ‘eyes’ are
the male pollinia hidden by a hymen which will open when the pollinating
insect touches the ‘beak’.
The epithet ‘odorata’ implies a
fragrance, but I have never felt any fragrance from any wild Thai variety,
not even at night. I could be blocked to its fragrance, but I do catch the
fragrance of other Aerides. With such a huge geographical range there is
plenty of room for local adaptations and varieties.
Perhaps ‘Aerides odorata’ is in fact a
cluster of several closely related species, each with its different
morphology, colour scheme and chemistry as an adaptation to different
pollination biology? Only molecular analyses of their DNA can reveal if
there is a gene flow (mating) between the many different populations or not.
From the orchid conservation aspect it
is important to work with local varieties, since a Himalayan variety might
have problems surviving in a Borneo rain forest. The cloned strains grown
for orchid houses abroad may degenerate quickly (i.e. develop new shapes,
forms and fragrances selected by gardeners, not by nature) and so they
provide little information of importance to science.
If any of our readers have experience
from Thai wild strains and their fragrance, or have seen the presumably
large insect needed to open the stiff flowers, please let me know.
The Malaysian Pit Viper
Snakes are a reality to a monsoon
gardener, even in towns and behind walls in gated communities. Although most
Thai garden snakes are small and harmless to people, in fact beneficial by
controlling rodents, treesparrows and snails, some snakes are potentially
If you are
bitten by a snake, it is good to know which species to get accurate and
swift treatment at the hospital. The body of the pale Malayan pit viper has
distinct dark triangles. The body is thick, compared to that of the marbled
cat snake. Another harmless look-alike is the banded kukri snake, but that
species lacks the IR pit and has a round pupil.
In a previous blog I treated the
Indochinese spitting cobra. Yesterday Khun Nived picked up an upside down
bucket on a stool and noticed a strange ‘stone’. When she looked closer she
realized it was a snake. I was asked to come and take a look, and sure
enough this was my first encounter with the pale form of the Malayan pit
viper (Calloselasma rhodostoma, Viperidae, Crotalinae).
The snake was absolutely motionless,
which is good and bad. It is good because it is not actively aggressive. It
is bad because it trusts its camouflage so much that it will not move away
like most other snakes, so if you put a hand or foot on it, it may bite.
Luckily here in Chiang Mai there are good hospitals so the effects are
usually not severe for an adult human, but without treatment you may lose a
limb or even your life. I know of a gardener north of town who was bitten by
this snake. He went to hospital but was back again at work the following
The pit viper venom contains compounds
which lower the blood pressure (ACE inhibitors). This mechanism has been
copied by modern science to make medicines against high blood pressure.
Cilazapril is one such commercial medicine often used in Thailand against
high blood pressure.
This relative of the rattlesnakes is
nocturnal and hunts rodents but also other reptiles and amphibians. To be an
efficient night hunter of rodents, it has a pit between the eye and the
nostril which is sensitive to infra red, i.e. it can ‘see’ heat at night.
Being a foreigner in a Thai garden I
have to accept the Thai culture. This snake was killed by Khun Densak for
safety reasons, but I took the opportunity to study it more closely. The
pupil of the eye is just a slit. The pit for infra red vision is clearly
seen between the eye and the nose pit. The elegant ‘eyebrow’ is another
To keep snakes away from areas where
you live, it is good to keep some chickens. They hunt young snakes. A
sighting of a venomous snake should encourage the house owner to keep
children and pets indoors until next day. To my experience tropical snakes
come and go, they rarely stay in one area for long. Most snakebite patients
are men bitten in their hands when trying to kill a snake. At Dokmai Garden
there are snake-hunting mongoose, guinea fowl and raptors and so we have
only seen the Malayan pit viper once in five years. Nobody has ever been
bitten by any snake at Dokmai Garden. Remember that Nived must have been
very close to this snake when she picked up the bucket – still nothing
happened. I am more worried about traffic accidents.www.dokmaigarden.co.th.
The Cuddly Cat Orchid is in blossom
A common native Thai orchid which do
not mind six months of drought is the ‘cuddly cat orchid’ (Trichoglottis
dawsoniana syn. Staurochilus dawsonianus, Orchidaceae). English vernacular
names are needed to create an interest and concern about native Thai orchids
also among tourists and foreign settlers. This vernacular name is derived
from the lip looking like a yellow cat’s body stretching its paws for you,
and the column which may resemble an animal’s face. An alternative name I
have seen is ‘Dawson’s Staurochilus’, but I agree with André Schuiteman at
Kew Gardens that the genus Staurochilus is superfluous and so the orchid
should remain a Trichoglottis. In any case that vernacular name is not too
different from the (obsolete) scientific name.
father of four I am forced to learn about Pokemon (Japanese cartoon
characters) and to me the orchid’s lip and column reminds me of the animal
‘Pikachu’. The colours, morphology and scent (undetectable to the human
nose) are aimed at its special pollinating insect, still unknown to science.
Since the orchid produces fruits at Dokmai Garden, the insect seems to be
present too, although hitherto unknown to us.
Since this orchid species was
successfully established in the Dokmai Garden monsoon woodland we are now in
the process of moving out almost all specimens from the Orchid Ark nursery.
Being a strong survivor in nature we do not think this species is in
immediate danger in the Thai forests. It is a good beginner’s choice for
somebody interested in growing native orchids in his monsoon garden. Simply
buy it from a CITES certified dealer, mount it in a deciduous tree and allow
it to follow the monsoon cycle, i.e. leave it alone.
Who was the ‘Dawson’ the German
orchidologist Heinrich Gustav Reichenbach wanted to immortalize by creating
‘dawsoniana’ in 1868? One source claims it is after Dawson Turner
(1775-1858), a botanist. That seems unlikely since that Dawson is a first
name. Another source claims the orchid was named after orchid grower James
Dawson of Meadow Bank, Glasgow, Scotland. I think it is after Thomas Dawson
Esq., an industrialist also from Meadow Bank near Glasgow, whose gardener
James Anderson was an orchidologist corresponding with Charles Darwin. In
1868, the same year as ‘dawsoniana’ was coined, James Anderson received the
Bateman medal for the greatest number of marks for orchids exhibited at the
Royal Horticultural Society (England). “The wonderful Meadow Bank collection
was then in its prime…” (From Lewis Castle (1886) Orchids, their structure,
history and culture). It is possible that the gardener James Anderson has
been confused with his patron Thomas Dawson and so ‘James Dawson’ became a
fusion. If anyone knows for sure, please let me know.
Blossom in the rainy season
To me, this
is a rare garden plant, because you can not buy it anywhere.
This morning I woke up surrounded by
the music of rain. An early morning stroll in the garden made me think how
amazingly beautiful the rainy season is. The whole landscape has changed
colours in just a couple of days. There are all shades of green, from the
lightest yellow-green to a deeper maroon-green. A majestic Amorphophallus
paeoniifolius (Araceae) is about to bloom, and the rare Firmiana colorata
(Malvaceae) has already made new leaves (always looks dead in the dry
Unfortunately I slept too well last
night, so when I woke up the rain meter was already full (35 mm). If I add
those 35 mm to the continuous rain in the morning and lunch we have so far
received at least 86 mm. This is not a problem, it is a blessing. The
problems appear when we get such amount of precipitation in just one hour,
like last year, twice!
This amount of rain will probably
trigger termite swarms, frog choirs and in a few days masses of mushrooms.
It will also wake up zillions of butterflies. Many times I have remarked
that of the 1000+ plant species at Dokmai Garden the South American ‘golden
dew drop’ (Duranta erecta, Verbenaceae) is the main nectar plant for
butterflies. This year, for the first time, I have a native Thai
competitor. I observed it in the jungle being surrounded by a cloud of
butterflies so I returned later to collect seeds. They germinated easily and
one sapling is now mature enough to bloom. This rainy morning I took the
opportunity of sitting down with my literature to try to identify it.
Its fringed white petals revealed its
affinity with the genus Elaeocarpus (Elaeocarpaceae). This is a tropical
family you hardly find in Europe or North America, so only specialized
botany professors from those areas would know about them. Llamas eminent
book on tropical garden plants and Wikipedia do not treat this plant genus
which encompass some 350 species. The Thais know them as ornamentals
(Elaeocarpus grandiflorus) or jungle fruits. The scientific name is derived
from the Greek word ‘elaia’ meaning ‘olive’ and ‘karpos’ meaning ‘fruit’.
However, this plant is not related to the olive trees (Olea europaea,
Oleaceae), it is a superficial resemblance used by Linnaeus who described
The key of the Flora of Thailand 2:409
(1981) is technical, and the species description contains no remarks on
ethnobotanical uses. That key demands the use of a dissecting microscope.
Still, it is useful to consult several different keys to identify a species,
and so I used this key and also that of Gardner et al. (2007). Both keys
point at the same species: Elaeocarpus lanceifolius. While Gardner et al.
(2007) claim it blooms in June and that it is found at mid elevation
800-1200 meters altitude, that may reflect the experience of the authors.
Flora of Thailand claims it is more frequent at 300-450 meters altitude
which coincides with where I found it. My plant blooms now which is also in
accordance with Flora of Thailand. Its mother site was in the evergreen
valley of Mae Kanin Tai south of Chiang Mai, but it may grow even in
Savannahs. The worldwide range encompass India and Southeast Asia including
The main features for identification
are small flowers (1 cm diameter, 8 mm long petals), mainly arranged in
racemes in axils of fallen leaves, below the tuft of young leaves. The
leaves are smooth without swollen stalks. The anthers lack a bristle at its
An obnoxious but impressive garden ant
There are about 12,000 species of ants
hitherto described in the world, of which 247 species reside in Thailand,
but many more remain to find. One ground dwelling ant which you find
commonly in the Chiang Mai gardens is the ‘marauder ant’ Pheidologeton sp.
It is easily identified by its trails with zillions of black, small workers
which are happy to bite you, large workers and massive gigantic ‘soldiers’.
A Thai name is simply ‘mot dam’ (black ant).
small foraging marauder ant hitchhikes with a massive soldier of the same
Marauder ants tend to make huge
underground nests in sandy soils from which they launch foraging campaigns.
This means that a certain spot in your garden may be clear from ants in the
evening, but next morning when you walk about in kimono holding a cup of
lovely coffee, your bare legs might be attacked by marauders and they do
make you run and brush your legs. The massive soldiers move slowly like
tractors so they are of little significance to the gardener. Like in the
army, these living tractors may carry many small workers. They are also good
at seed cracking and for towing larger prey.
Ants in general is one reason
explaining the cleanliness of the Thai people. When a dirty farang like me
resides for too long in a tent or room, the marauders happily invades your
territory to liberate you from bread crumbs. Frequent cleaning is important
to keep them away. Many animals feed on ants so a rich biodiversity in your
garden may lower the numbers.
If an ant trail goes into your house
because these hunters and gatherers spotted potato chips under your sofa,
then pour some whiskey on their door step to wipe out the chemicals
(pheromones) the ants use to find their way. This causes immediate chaos and
proceed without delay with the vacuum cleaner to remove the invaders and
their targets (dead spiders, pop corn etc). After counterattacking the
immediate invasion, proceed by launching an attack on their head quarters.
Many litres of boiling water poured rapidly from air borne tea pots may be
sufficient. The aim is to eliminate the ant queen. Without a leader the
nation will shatter and her mercenaries will get lost in the jungle. If this
bombing is unsuccessful due to the depth of the fortress, you may want to
try an ant specific bait. Although chemicals should be avoided, there are
cases when it is either you or them. Unlike a gas which kills anything, a
bait is specific and is brought home by workers which will poison the ant
These ants are native and ecologically
they do provide (other) pest control and also disperse seeds.
In previous articles I have mentioned
three other common ants in Chiang Mai gardens: the exotic pharaoh ant, the
exotic fire ant and the native red weaver ant which is food and often an
ally in pest control.