I looked up to find the tree it might be 
attached to, and sure enough, an enormous 
conifer towered above me. I looked up at this 
red-barked giant and saw something wonder- 
fully strange and familiar. It looked like a cross 
between the bald cypresses that I knew from 
Georgia and the coastal redwoods (Sequoia 
sempervirens) from California, both members 
of the cypress family (Cupressaceae). I found 
several other knees as I walked up to inspect 
the tree. This, I proclaimed to Maxwell, must 
be a very special tree! Maxwell, however, like 
many other tropical botanists, was not as inter- 
ested in conifers as much as the epiphytes that 
might grow on them. He thought nothing of it. 
Meanwhile, I collected the samples of small 
cones, foliage, and bark of this tree, which I sent 
to conifer expert Philip Thomas at the Royal 
Botanic Gardens, Edinburgh, for identification. 
Documenting the Mai Hing Sam 
Conifers are dominant or codominant parts 
of primary- and secondary-growth evergreen 
forests throughout the Annamite Mountains. 
In Vietnam, for instance, the mountains host 
a particularly rich assemblage of thirty-three 
conifer species, of which the cypress family 
(Cupressaceae) has seven.* When I asked peo- 
ple in the neighboring Lao communities about 
the enormous tree that I had encountered, they 
provided a name: mai hing sam. Mai means 
“tree,” hing is a modifier for the kind of tree, 
and sam means “swamp,” or what ecologists 
would describe as a forested wetland. 
As it turned out, the mai hing sam was, 
indeed, special. When Philip Thomas replied 
to my email, he identified the species as Glyp- 
tostrobus pensilis (known as the Asian swamp 
cypress), which the International Union for 
Conservation of Nature has classified as criti- 
cally endangered.° In 2007, the scientific com- 
munity was aware of only 250 individuals of 
this species in the wild in Vietnam, where most 
were spindly, unhealthy young trees, growing 
in two small stands in the middle of coffee and 
corn plantations. Other stands in China were 
presumably planted.° Due to its rot-resistant 
wood, Glyptostrobus pensilis is highly sought 
Glyptostrobus 23 
after in the luxury timber market and is used 
for a variety of structural and boat-building uses 
by local communities. It is threatened (like so 
many endangered species) by illegal logging. 
As I learned more about the two populations 
in Vietnam, I realized how remarkable the mai 
hing sam in Laos really were. The trees in Viet- 
nam grew very close together and, like those 
in China, appeared like they could have been 
planted. Boardwalks had been built within the 
stands to get around. Dams located beneath 
each of the stands were used for agricultural 
irrigation and raised the water levels for the 
trees significantly. In contrast, the trees that we 
observed in Laos were erect and widely spaced, 
as expected for a wild population. The crowns 
of the mai hing sam in Laos were only found in 
the top third of the trees, with no limbs below 
for us to climb to the seed-bearing cones. In 
the Vietnam population, perennial and annual 
branchlets were numerous along the main 
bole, appearing to be epicormic growth. This 
form suggests that the trees in Vietnam were 
responding to stress from inundation. Also, 
some of the trees in Vietnam were cut down 
years ago and had resprouted.’ 
I immediately told my colleagues about 
the mai hing sam discovery so that we could 
develop a strategy to describe and protect 
this stand. I also informed the Nam Theun 2 
Power Company (NTPC) of the discovery and 
asked to spend time describing the tree and 
its ecology and to have a surveyor document 
their elevation relative to the proposed reser- 
voir footprint. I was not allowed time to docu- 
ment this stand properly, however, and I was 
only able to record the number and size of the 
trees and basic soil characteristics. There were 
approximately one hundred trees in the stand, 
and many were three feet in diameter at breast 
height. We only had very rough elevation infor- 
mation from our GPS units, but it was clear 
that the trees—along with many others that 
we were unable to document—would likely be 
within the reservoir footprint. 
In desperation to protect these rare trees, I 
contacted the Nam Theun 2 Panel of Experts, 
an audit group that was in charge of assessing 
Facing page: Forests in the Annamite Mountains are rapidly disappearing due to forestry, agriculture, and hydropower 
development, along with other causes. Philip Thomas (right) stands beside Glyptostrobus pensilis within a rice paddy. 
PHOTO BY DAVID MCGUIRE 
