Woody > Tsuga > Tsuga ulleungensis > Tsuga ulleungensis
Tsuga ulleungensis
Origin: This rare tree is considered an endangered species due to its restricted range. Tsuga ulleungensis is a relatively new species of the genus Tsuga. The tree was discovered in Ulleungo, South Korea, while trying to find out why Eastern species that would have greater resistance to the Hemlock Woolly adelgid. The insect spread to North America, causing destruction due to the lack of predators present. It was officially classified in 2017 by team lead Garth Holman, a research associate at the University of Maine. When initially discovered the Tsuga ulleungensis was thought to be a disjunction population, however the two species where genetically dissimilar; much like it’s close relative Tsuga sieboldii.
Mike's
Opinion
"
The Tsuga has a beautiful irregular canopy that brings interest to the natural landscape of the island of Ulleundgo. The uniqueness of its form brings a more rugged and untamed look to the Tsuga genus. Its moderate size for a hemlock allows for potential landscape use.
Michael Pascoe, NDP., ODH., CLT., MSc. (Plant Conservation)
"
| Family |
| Pinaceae |
| Genus |
| Tsuga |
| Species |
| ulleungensis |
| Category |
| Woody |
| Type |
| Tree (evergreen) |
| USDA Hardiness Zone |
| 6 - 8 |
| Canadian Hardiness Zone |
| 7a - 9b |
| RHS Hardiness Zone |
| H5 |
| Temperature (°C) |
| (-23) - (-18) |
| Temperature (°F) |
| (-10) - 0 |
| Height |
| 22 - 30 m |
| Spread |
| 4 - 8 m |
Photographs
Cultivars
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Description and Growing Information
Flowering Period
| Landscape |
| Hemlocks are typically used for lumber, however, the Tsuga ulleungesis trees are used as wildlife habitat due to scarcity. Due to their rare nature, these trees have been used as specimen plants as well. |
| Cultivation |
| Tsuga ulleungensis is grown naturally on very acidic volcanic soils in the wild. Most Hemlocks in the genus prefer acidic soil, with a pH of 7.0 or lower and well draining soils. From their location on the south facing side of the mountains of Ulleungdo, one can infer that they can tolerate and do well in harsher light. |
| Shape |
| The plants shape is broad, upright and irregular. |
| Growth |
| Slow |
| ID Characteristic |
| Tsuga ulleungensis is an evergreen conifer characterized by its distinct wavy margins to its’ cone scale bracts. It can also be identified by their reddish-brown cones and the white bands on either side of the mid rib. |
| Pests |
| Hemlock woolly adelgid often infects the Tsuga ulleungensis, however the insects are managed using natural pests. Not a major concern if predatory insects are in healthy numbers. |
| Habitat |
| Tsuga ulleundgensis is found in acidic, well draining, moist areas. Also found on North facing slopes on rocky ridges on elevations of approximately 300- 500 m above sea level. Located in forests usually dominated by the Japanese White Pine. |
| Bark/Stem Description |
| The bark/stem is smooth and measures in 1-1.5mm in diameter. |
| Flower/Leaf Bud Description |
| The flower/leaf bus is globular or obovoid shape. |
| Leaf Description |
| The measurements are 10-15mm long linear leaves, with 1.0mm-1.5mm petioles, approximately 1-1.5mm thick in diameter, attenuate bases with slightly thickened margins. Needles have two broad white bands on each side of the midrib. Bands typically include 8 stomata gradually decreasing to 2-3 proximally and 4-5 distally. Includes one resin canal measuring approximately 0.5mm in diameter at the midpoint of the leaf. |
| Fruit Description |
| Pollen cones are a burgundy colour measuring 0.5-1.0 mm and the juvenile seeds are purple. Bracts are wider than long with crenulate margins. Mature seeds are globular to ovoid in shape. Each cone contains 20-26 seeds. |
| Colour Description |
| The plant remains a stunning dark green colour throughout the year. |
| Notable Specimens |
| One notable specimen is at the Morris Arboretum in Philadelphia, United States of America. Another well known specimen is the 30 m tall mature tree that resides in the protected reserve of Namseo, Taeha Reyeong in Ulleungdo, South Korea. |
| Propagation |
| Due to low seed production, natural methods of seed production are not used. Vitro propagation and cryopreservation through somatic embryogenesis has been implemented by researchers. |
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