Mai rice field scenery with a Thai willow in the centre. To see this tree in
reality, drive along the Chiang Mai canal road and make a stop at the sandy
flat area just north of the Hang Dong golf club. With good shoes you can
walk between the rice fields. There are good sightings 500 m north of the
Ton Kwain intersection too, but it is hard to walk up to those trees. The
tree is called ‘kai non’ by the nearby farmers, but Smitinand writes ‘khrai
This time of the year you do not see
many native trees in blossom along the Chiang Mai roads. One extraordinary
exception is the Thai willow (Salix tetrasperma, Salicaceae). To me it is
most surprising that this enchanting tree, suitable for erosion control
along streams and a lovely ornamental near your pond, is so difficult to
find in a nursery. We had a small specimen at Dokmai Garden but we managed
to kill it when we moved it to another area. Yesterday I took new woody
cuttings which I liberated from leaves and flowers and planted in a sandy
and moist pot.
A strange phenomenon is that the Thai willow makes flowers and seeds in the
cold and dry season when there are hardly any other wild flowers
(November-January) and it becomes dormant and sheds leaves in the late rainy
season when most other native plants grow at maximum speed.
Its ability to grow in wet (flooded) habitats enables pollination at a time
when there is not much competition from other plant species, and seed
dispersal via the wind while it is still dry. In the dry season there are
more muddy surfaces available for seed germination than in the rainy season
when it is flooded. The dormancy in the rainy season may terrify a gardener
who thinks the tree is dead, but might be an adaptation to flooding, i.e.
shutting down the metabolism to lower the oxygen consumption and avoid cell
death due to drowning. However, I am not aware of other willows doing this
so I do find this species quite exceptional.
The tree was scientifically described and named by the Scottish director of
the Calcutta Botanic Garden William Roxburgh in the book ‘Plants of the
Coast of Coromandel’. www.dokmaigarden.co.th. [email protected]