Amentotaxus argotaenia yunnanensis (H.L.Li) Keng f.
Amentotaxus yunnanensis is an evergreen tree with a wide, ovate crown; it can grow up to 20 metres tall. The bole can be 25cm in diameter[
The tree is harvested from the wild for local use of its wood, and is also traded from Vietnam to China. It is sometimes grown as an ornamental in gardens and is also being investigated as a potential source of anti-cancer drugs.
Due to recent discoveries made of this species during intensive botanical surveys in Viet Nam, this species is now known to have a wider distribution than previously assumed. The majority of its (sub)populations appear to be in Viet Nam, not in China, and it is also in Viet Nam where the species attains large tree size. A re-assessment for Viet Nam gave it the status of Vulnerable (VU) for that country. In China it has been given the status of Endangered (EN); this has lead to a similar global status based on the earlier assumption that most populations were within that country. It is threatened mainly by deforestation, leading to fragmented areas of forest with declining population size in most. Targeted logging removes seed-producing trees, which may lead to diminished recruitment of seedlings and saplings in the population. The plant is classified as 'Vulnerable' in the IUCN Red List of Threatened Species(2013)[
E. Asia - China (Yunnan, Guizhou), northern Vietnam, Laos
An understorey tree, occasionally growing larger and becoming a canopy tree, scattered in mixed evergreen and deciduous broad-leaved forests; at elevations from 800 - 1,600 metres[
|Other Uses Rating||
|Cultivation Status||Ornamental, Wild
Amentotaxus species are generally natives of warm temperate, subtropical and tropical forested areas in east Asia. Most are tolerant of some frost, but only if there has first been a hot summer to fully ripen the wood. They therefore usually only succeed outdoors in warm temperate to tropical areas[
]. Amentotaxus yunnanensis is found in subtropical to tropical forests at elevations up to 1,600 metres. It grows in area where the mean annual precipitation is above 1,500mm and fog is frequent[
]. The mean annual temperature for plants growing in Vietnam (the more tropical part of its range) is 17 - 20°c[
]. Plants can withstand some frost, tolerating occasional, short-lived temperatures falling to between -6.6°c and -1.1°c[
Succeeds in fairly dense shade when young but becoming more tolerant of full sun as it grows larger[
]. Succeeds in a wide range of soils, preferring one that is well-drained, moist and sandy[
]. The tree is most commonly found in mixed forests on limestone karst formations in the wild; on substrates derived from silicious rocks (granite, gneiss) it is sometimes becomes a large tree in manily broad-leaved forests. It is a relatively shade tolerant species, with seedlings and saplings successfully growing up under a forest canopy[
This species is in limited cultivation, often as a bonzai plant[
A dioecious species, both male and female forms need to be grown if fruit and seed are required.
The leaves and stems of various species in this genus are being investigated as a potential source of compounds used in anti-cancer drugs[
The seeds are rich in oil[
]. No uses are given.
The white wood of larger trees is valued for furniture making, construction, agricultural implements etc, while smaller sizes go to handicrafts and tool making[
]. Much of this is done in China and it is likely that timber of Vietnamese origin is used[
Seed - can be very slow to germinate, often taking 2 or more years[
]. It is best sown as soon as it is ripe in the autumn when it should germinate 18 months later. Stored seed may take 2 years or more to germinate. 4 months warm followed by 4 months cold stratification may help reduce the germination time[
]. Harvesting the seed 'green' (when fully developed but before it has dried on the plant) and then sowing it immediately has not been found to reduce the germination time because the inhibiting factors develop too early[
]. Seed voided by birds after they have eaten the fruit tends to germinate well, so scarifying the seed prior to sowing might be useful. Prick out the seedlings into individual pots once they are large enough to handle and grow them on in pots in a cold frame. The seedlings are very slow-growing and will probably require at least 2 years of pot cultivation before being large enough to plant out. Any planting out is best done in late spring or early summer, after the last expected frosts[
Cuttings of half-ripe terminal shoots, 5 - 8cm long, July/August in a shaded frame. Should root by late September but leave them in the frame over winter and plant out in late spring[
]. High percentage[
Cuttings of ripe terminal shoots, taken in winter after a hard frost, in a shaded frame[