Common Name: Chinese Swamp Cypress

General Information

Glyptostrobus pensilis is a semi-evergreen tree with a pyramidal to more rounded crown; it usually grows up to 10 metres tall, occasionally reaching 25 metres, with one planted tree recorded at 39 metres. The trunk can be 120 - 150cm in diameter and is markedly buttressed at the base, especially when growing in wet soils and standing water[].
The plant is harvested from the wild for local use as a medicine and source of materials. It is widely cultivated, especially in China as an ornamental tree, often being felled when large enough for its timber and then being replanted[].
This species is widely cultivated in southern China and planted along rivers and canals as well as in parks; except for the latter localities mostly to harvest the timber followed by replanting[].
Glyptostrobus pensilis was formerly very widespread in China, Viet Nam and possibly Lao PDR. In China and Viet Nam most of the natural plants have been killed due to expanding agriculture. It appears that there are no plants remaining in the wild in China and that the only remaining natural subpopulations are in Viet Nam and Lao PDR. Although the total number of trees is more than 250, very few, if any are producing viable seed and the majority of trees in Viet Nam are in decline. The plant is classified as 'Critically Endangered' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

None known

Botanical References

,

Range

E. Asia - southeast China (Fujian, Hunan, Guangdong, Guangxi, Jiangxi), Vietnam, ?Laos

Habitat

Heliophilous, it is intolerant of competition and usually grows in pure stands or solitary along streams. Mainly found on river floodplains and in deltas, always near or in water, where it develops a buttressed base and occasionally pneumatophores[].

Properties

Conservation Status	Critically Endangered
Medicinal Rating
Habit	Semi-deciduous Tree
Height	10.00 m
Growth Rate	Medium
Pollinators	Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

Glyptostrobus pensilis is rarely hardy in Britain[], plants do not succeed outdoors at Kew[]. Although said to succeed in zone 8, this species is barely hardy in colder zones without hot humid summers (to ripen the wood) and even then only attains 3 - 4 metres in height[]. The southern distribution of this species is quite hardy but is sometimes thought to be tender due to its being planted in the wrong site. It must be given a wet soil, preferably standing water[].
Requires a sunny position[]. Thriving beside water and in damp places, plants require a very damp soil and will prove hardier if they are standing in up to 60cm of water[, ]. They prefer growing in areas with hot summers and will die within 2 years if they are planted in a dry site[].
This species is considered to be a symbol of good luck in its native regions and consequently it is not normally deliberately felled by villagers[].
Slower growing than the vegetatively similar swamp cypress, Taxodium distichum, it is late coming into leaf in the spring and also to lose its leaves in the autumn[].
Trees occasionally reach 25 metres tall in the wild[].

Edible Uses

None known

Medicinal

Antidote, oxytocic. Cures ascites, treats animal bites and dropsy of pregnant women[].
A decoction of the shoots is used in the treatment of fever, hepatitis, skin complaints etc. It is said to be an anodyne for animal bites[].

The wood is reputed to have anti-cancer properties in Vietnam, although there is no scientific evidence to support this[].

Agroforestry Uses:

Having an extensive root system, it is often planted in wet places for erosion control, to stabilize river banks and paddy field walls[, , ]. It is also used as a windbreak[].

Other Uses

The roots have high buoyancy and are used
Tannins extracted from the bark and the cone scales are used in tanning, dyeing, and fishing nets[].

Wind-felled trees are used in constructing buildings, bridges and furniture[].
The rather soft, yellowish wood is like most cupressaceous wood decay resistant and finds uses in China ranging from furniture to building of bridges[, ]. In Viet Nam the wood is highly valued for crafts[].
The wood of the roots is very light and has a high buoyancy. It is used for making items such as life buoys, bottle corks, etc[, ].

Propagation

Seed - we have no information for this species but suggest sowing the seed in a cold greenhouse in late winter. When they are large enough to handle, prick the seedlings out into individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Give the plants some protection from the cold for their first few winters outdoors.
Cuttings. Again, no details but we would try taking cuttings of mature wood in the late autumn or winter in a frame.