Cikkek, publikációk
2018. december 10.  hétfő


The Genus Trachycarpus


The Genus Trachycarpus
by Martin Gibbons and Tobias W. Spanner

 

Only a few generations of being generally available in cultivation, their special characteristics are likely to be lost, emphasizing the urgent need for serious protection efforts for its remaining wild populations. A hundred years ago there were huge numbers of mature trees up to 12 m in height in the wild. Now they have all been cut down for the fibres.

trachycarpus_wagnerianus2.jpg (49372 bytes)

If T. takil is easily confused with T. fortunei, then Trachycarpus wagnerianus is not easily confused with anything! Indeed it is unmistakable, especially when young. It has small, stiff leaves, less than 75 cm (30 in) across, the leaf segments edged with white wooly fibres. The leaves are so stiff that even strong winds have no effect on them; thus they are far and away the most suitable palm for windy sites in the temperate garden. Additionally, they are incredibly beautiful: neat, tidy, upright, jaunty. Although there is some speculation as to whether it might still exist in the wild somewhere, in Japan perhaps, hidden on some remote mountain top, curiously it has never been found and, if wild populations ever existed, they are probably extinct. The original introductions to the western world came to Italy early this century when a Mr. Winter bought the entire stock imported from Japan by the German horticulturist Albert Wagner, after whom he named the species. Despite the name T. wagnerianus originating from horticulture, differences from T. fortunei were enough to convince Beccari that it deserved species status and, indeed, it is quite impossible to confuse it with anything else.

Slow growing and seemingly distorted when young, after 3 to 4 years they literally explode into growth and beauty and, given the rich soil and watering that they need, can double their size every year for a few years, eventually reaching 10 or 20 feet in height, and always retaining those small, unique leaves. Why they are not more common is something of a mystery. Perhaps their slower early growth? The confusion with the names? Whatever the reason, they simply have to become more popular in the next few years as more and more people see how irresistible they are. Just as hardy and as easy to cultivate as T. fortunei, the added benefit of wind resistance will ensure their popularity as soon as they are more widely available.

trachycarpus_nanus.jpg (43706 bytes)

Equally unmistakable is Trachycarpus nanus, the only member of the genus not to grow an above-ground trunk (except rarely and then only to a foot or so). Native to Yunnan province in China, it is under threat in the wild due to predation by goats which roam throughout this small plant´s entire range. While the leaves are too tough to eat, the young inflorescense provides a tasty morsel for these pests which, thus, prevent the plants from reproducing, and since its maximum height is only 2 or 3 feet, it never grows above the danger level. This interesting small palm remained in almost total obscurity from 1887, when it was first reported by Father Delavay, until 1992 when we mounted a small expedition to relocate it (see Principes 37:2, 64-72). A few seeds have subsequently come out of China and it is beginning to appear in cultivation in Europe and the U.S. It is a pretty species, with very deeply cut, sometimes green, sometimes blue leaves, their segments numbering not more than 30. Growing between 1800 and 2300 m a.s.l. (5900 to 7500 ft), it is again very hardy to cold and a perfect small palm for the temperate garden, although it is slow and initially somewhat more difficult than most other members in the genus. It requires a very well drained, heavy soil and a position in full sun to look best.

trachycarpus_oreophilus1.jpg (42188 bytes)

The only species to occur in Thailand is Trachycarpus oreophilus, the Thai Mountain Fan Palm, which, with a proper botanical description, appeared in the October 1997 issue of Principes. It grows at some altitude on only one mountain range, Doi Chiang Dao, in the northwest of the country near Chiang Mai and may possibly also occur across the border in Burma. The area where it grows at 1700 to 2150 m a.s.l. (5600 to 7000 ft) is almost continually covered by cloud and mist; it is cool and rather damp, which makes this another perfect contender for a humid temperate or subtropical garden. The name ´oreophilus´ means ´cloud-loving´. The mountain crests and ridges where they appear are very exposed and windy from time to time, resulting in much damage to the leaves. Since there is not a single mature tree in cultivation, we can only imagine its final, sheltered, appearance for some years to come. It is an exciting prospect! The wild trees have a slim, naked trunk, caused by the very short fibrous leaf-bases soon falling, a compact, broader-than-deep, hemispherical crown of leaves, these regularly split into 60 or more segments and self-shedding on dying. So far, with the possible exeption of T. nanus, it has proven to be the slowest of all the species in cultivation, taking several years to put out its first divided leaf, though perhaps it will speed up once established. A rich but well drained soil is recommended.

trachycarpus_princeps.jpg (67592 bytes)

The adventure of our discovery of Trachycarpus princeps, the Stone Gate Palm, can be read in Pricipes 39 (2):65-74. It grows near to where the borders of China, Tibet and Burma meet, politically something of a hot-spot. What the Principes article doesn´t tell is that the previous year we had made an ´unofficial´ attempt to get there. This whole area of China is closed to foreigners and with our height and obvious Western appearance, we stood out like sore thumbs. Nonetheless, we hitch-hiked successfully west from Kunming as far as the Mekong River which we crossed by a footbridge. Ahead of us lay an over 4000 m high mountain range and since there appeared to be no road crossing it we had no alternative but to climb it ourselves, in the company of three Chinese peasants who offered to guide us, for a fee, which increased with the altitude.

We began with much enthusiasm and energy, losing both after we´d been going for a few hours. That first night we slept, exhausted, in a hovel surrounded by a sea of mud in which cows and goats were pissing and children were playing. The next day we continued upwards through different zones: a thicket of dense bamboo, a forest of tree-like Rhododendron on mossy ground, a beautiful wetland area with stunted, almost bonsai-like conifers, a broad band strewn with rocks the size of car engines. A second night in another hovel, an early start and we headed again towards the summit. Emerging above the tree line we came onto a grassy meadow, in which were growing thousands of Gentians of the most intense blue. By the time we actually reached the summit at 3900 m, we were so tired we were almost hallucinating; it really was the most physically exerting thing either of us had ever attempted. Down the other side then, our legs feeling like rubber.

Soon after beginning our descent we were stopped by an aggressive young man in military uniform, who burst out of a hut. He spoke no English but the word ´passport´ cropped up in his speech. If we were alarmed by this turn of events, our guides were terrified, especially when we began handing over money to ease our passage. When we had paid over about $20 he angrily waved us on our way, and for a few hundred yards we even forgot our tiredness as we sped down that mountain track! That night, we finally we made it down to the valley bottom, crossed the Salween River by footbridge and sneaked into a small town. Our attempts to maintain a low profile proved useless; we were soon surrounded by the entire population, most of whom had never seen a European before. So remote was this town that the police officer there didn´t realize that we were seriously off-limits and the next day, simply helped us on our way. At that point though, our luck ran out. Forty miles up the road, so close to our goal, we were arrested for real and sent, with a police escort, all the way back to civilization. Back in Europe, we had to wait a whole year while our official application was considered, and, on payment of $2000 for ´logistical support´ we were allowed up there again, in the company of a Chinese professor and an interpreter. Finally, we found our palm.

Perhaps the most beautiful of the genus, the backs of the leaves of Trachycarpus princeps are covered with a pure white waxy substance, thick enough to be scratched off with a finger nail and which easily differentiates it from its closest relatives. It grows in an area of incredible natural beauty in a deep gorge on the cliffs of a 1000-foot-high split in the mountain range, which the Salween (Nu Jiang) River has cut out of the marble stone. We were unable to find any seeds, and since further attempts to visit the site seem to be quite impossible, it is unlikely that this beautiful species will find its way into cultivation just yet. From time to time seeds of ´T. princeps´ have appeared in seed dealers´ lists. These are NOT the real thing (some are not even reniform) and should be avoided. We can say with some confidence that no seeds of this species have ever been brought out of China to this day.

B. Those with oval-and-grooved seeds:

trachycarpus_martianus.jpg (72107 bytes)

Trachycarpus martianus can be seen at a few botanic gardens around the world: Huntington, Sydney, Kew; but it is by no means commonly encountered. Most reports of this palm turn out to be T. fortunei with a bare trunk! This is not, I repeat NOT, a distinguishing characteristic. The splits in the leaves, very regular in this species, while irregular in T. fortunei, and the leaf segments numbering 65 to 75, occasionally up to 80 are a much more reliable guide. This, together with the seed shape, means they should really never get confused.

It is distributed in two far-apart areas, one in central Nepal, one in Meghalaya Province (and possibly also further east) in India, separated by several hundred miles. At one time they were thought to be separate species, the eastern population having originally been described as ´T. khasianus´, but, though there are some subtle differences, they seem basically the same. The Nepal form grows at considerably higher altitude and should prove to be somewhat hardier to cold. They are rather beautiful palms, slim, elegant, with neat crowns of fine, fan shaped leaves, as stated above, regularly divided and with numerous segments. The petioles are covered with a white tomentum--tiny white fibres--giving the petiole a slightly hairy appearance.

As with T. oreophilus, the places where they choose to grow in the wild are rather exposed and windy. Cultivated plants look quite different and would sometimes hardly seem to be the same species. Seedling growth is reasonably fast and since seeds are now more frequently available there is no reason why this beautiful palm should not, in a few years´ time, be gracing the garden of every temperate palm enthusiast.

Trachycarpus martianus was reported as growing on limestone hills but, contrary to this, we have actually found them growing on highly acidic soils. This may be why they are sometimes reported as difficult to grow. Frustrated enthusiasts should maybe change the pH of their soil and try again. Young plants enjoy cool, humid conditions out of full sun.

trachycarpus_latisectus2.JPG (67245 bytes)

Photo courtesy and copyright © 1998, Ganesh Villa Pradhan, The Orchid Retreat; Kalimpong, West Bengal, India.

Only recently described, Trachycarpus latisectus, the Windamere Palm, was previously known as T. ´sikkimensis´ and many thousands of seeds have been distributed under that name, which was used as a working title but is now invalid and should not be used. ´Latisectus´ refers to the broad leaflets, indeed one of the distinguishing characteristics of this palm, which are around 5 cm (2 in) wide, very glossy, and of which there are around 70 in total, forming a very large and leathery leaf. It has a bare trunk and its seeds resemble those of T. martianus. Remaining in the wild in just one tiny, heavily altered location in the Sikkim Himalayas in north-east India, which is immediately threatened by destruction, it has only recently been introduced into cultivation, but is about to make a huge impression in the palm world. It is so big and bold, so distinctive, so cold-hardy, and so beautiful, it should, by rights, leave T. fortunei standing, in the popularity stakes. Also, it is probably the only species in the genus which, owing to its wide altitude range from 1200 to 2400 m (3950 to 7900 ft), will adapt well to hotter regions.

Seedling growth is slightly slower than the Chusan palm but speeds up as the young plants get bigger. As with the preceding species, spider mites seem iresistably attracted to it and steps should be taken to prevent them getting a hold on the young plants. As yet, there are no even middle-sized plants outside its native land, so cultivation experiences out of India are necessarily limited to plants only a few years old. As with other Trachycarpus, T. latisectus requires a rich, loamy but well drained soil. Young plants are best grown under some shade.

That´s the full complement. But what about the suckering species you may ask? In our opinion, it doesn´t exist. Sometimes in palms there is mutation, variegated leaves say, or simple instead of divided leaves, and individual plants may (rarely) grow several stems like a seedling T. takil we found in which the growing point bifurcated. This does not represent a distinct species however. We have also seen individuals of T. fortunei branching above ground, a curious reaction caused by damage to the growing point which has been observed likewise in many other palm genera. Furthermore, it is not uncommon for a Trachycarpus fortunei to appear to develop a side shoot but this is, in fact, the main growing point emerging from the side of the plant because the way up is blocked for some reason, possibly the result of some damage. Once this establishes itself, the original main ´stem´ will die back. If it is removed, the plant may well go on to produce another, but it is still the one and only growing point seeking a way out and up. One grower removed 4 such from a T. fortunei as he wanted a single trunk! As soon as one was allowed to develop, the main ´stem´ died. Others that are ´clustering´ are simply the result of several seeds being planted together. On every such specimen we have examined, including the type specimen of T. fortunei var. ´surculosa´, all the trunks are the same age (a bit of a giveaway that) and invariably both sexes are represented, impossible with a truly clustering palm. However, we would be delighted to be proven wrong.

The future.

One of the most significant things about several species of Trachycarpus that we have studied in the wild is the tiny size of their populations, in terms of either area or numbers. All the species apart from T. fortunei are more-or-less seriously threatened, some close to extinction in the wild. Trachycarpus takil, T. princeps, T. oreophilus and T. latisectus all grow in very small populations or areas that could so easily be missed were they not known about. You could pass within five hundred yards of some of them and not even dream that they were there. While this may be frustrating, it also has an exciting aspect to it. There may well be several more species just waiting to be discovered perhaps in areas apparently well documented. Northern Burma, for example, could be home to existing or even new species, but we will not know until the dreadful regime there falls and we can go and look for ourselves. The band along which most species grow seems to peter out towards north Vietnam. An expedition there may well turn up some interesting discoveries. Since we became interested in this genus we have discovered three new species along the Trachycarpus Trail. Who knows where it may lead next?

Martin Gibbons
The Palm Centre
Ham Central Nursery - Ham St., Ham
Richmond, Surrey, TW10 7HA
United Kingdom
Tel ++44 181 255 6191
Fax ++44 181 255 6192
Tobias W. Spanner
Palme Per Paket
Tizianstr. 44
80638 Munchen
Gemany
Tel ++49 89 1577 902
Fax ++49 89 1577 902

Note: This article was originally published in the Palm Journal and is reprinted here with permission from the authors. The photos in this article (except those with copyright and location information given) are copyright © 1998, Martin Gibbons and Tobias W. Spanner; most were taken in habitat.


Szerző: Martin Gibbons and Tobias W. Spanner






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