rootstock species

[sockhom]

It has been stated several times that some species from what has been called "Indochina" develop a rootstock in order to survive the dry period that most parts of Cambodia, Vietnam, Laos and Thaïland endure.

In Cambodia for exemple, april and may are very hot months (average temperatures are beyond 30s °C) and the rain only comes back for good in june.

See climate chart for Phnom Penh here:
en.wikipedia.org/wiki/Cambodia

In their Skeletal revision of Nepenthes (1997), Jebb and Cheek wrote about Nepenthes thorelii: "a plant of seasonnally dry grassland, surviving as a dormant roostock during the dry season when fires burn out the above ground vegetation".


See the rootstock of a Nepenthes smilesii specimen from Paris herbarium:
www.lhnn.proboards107.com/index.cgi?action=display&board=herbarium&thread=1258&page=1
See also this page where Dave Evans shows pictures of Nepenthes anamensis roots:
www.rci.rutgers.edu/~dpevans/Nepenthes/N_anamensis.htm#Michael


I have often read that growers and hobbyists refer to those rootstocks as "tuber roots" but more research need to be done to check the accuracy of this word.


Here is a list of the rootstock species:

- Nepenthes thorelii;
- Nepenthes smilesii (probably conspecific with Nepenthes anamensis, my friend Marcello Catalano will clear that for good);
- Nepenthes bokorensis;
- The "Tiger" and "Giant Tiger" sold by Neofarm, though their status have to be cleared;
- Nepenthes sp. "Viking";

Note that those plants (thorelii and smilesii) have not been formally classified as a taxonomic group.

Please, also note that this is just a provisional list. Some of us (especially Marcello Catalano) are currently working on those Indochina species and more plants are being discovered, though their status will have to be cleared too.

I have included Nepenthes bokorensis in this list but the presence of a rootstock has to be definitely proved. More field research and examination of cultivated material should quickly provide the answer.

I did not manage to check the roots of Nepenthes bokorensis but I do include the species in the above list for a few reasons:

- its taxonomical relation with Nepenthes thorelii, smilesii and sp. "Viking";
- the presence of a very dry season in Cambodia;
- and, most of all, the presence of Drosera peltata, a very well known tuberous Drosera, living along with Nepenthes bokorensis .

See this picture:








Please, post in this thread pictures of any above species rootsystem you may have.




François Mey.

[rainforest]

Dear Francois,
I have purchased N. mirabilis from Neo Farms and when they arrived, they too had thickened root sections. One in particular, had a true potato-yam appearing mass, even larger than any sp. Viking.

Is there any N. ampullaria from these monsoonal regions? Just curious if any amps have this characteristics as well.

M

[phissionkorps]

I've also noticed that argentii has some thick roots, but I'm totally unaware of them serving the same purpose:

[sockhom]

Hi Michael.

I've heard that N. ampullaria can be found in Thaïland but my friend Marcello Catalano hasn't managed to locate it yet.
It would indeed be interesting to check the roots.

François.

[sockhom]

Hello .


Here is a shot of a small Nepenthes bokor seedling. Like I said before, I did not manage to check the roots of this species in the wild but hey... look at this rootstock. Interesting, isn't it?





François.

[phissionkorps]

Now that's what I call a taproot

[rainforest]

That is indeed a taxonomic significance. I would be interested knowing if N. ampullaria has a rootstock in these countries. Will it then be designated as a variety of N. ampullaria?

M

[sockhom]

Hello !

Just found some fantastic pictures of root stocks from Yamada's site:

yamadanouenn.hp.infoseek.co.jp/nepenkakogazou3.htm

Check the "sp. Thaïland" and "N. thorelii" pictures.


François.

[Dave Evans]

Hello Sockhom,

Thanks for moving this thread from the moderators only section.

I would like to mention the seedlings of Nepenthes "red tiger" also have this very same, very thick tuberous root. And yeah, we can refer to them as tuberous, as they seem to be part stem and root at the same time. I say this because these structures are able to branch and form new stems.

After noticing these tuberous structures on the seedlings I tried an experiment:

When my "red tiger" were only about 0.7- 2.0 centimeters wide, I withheld water and the growing points aborted on several plants. Some of the rosettes completely dried out, turning shriveled, dead brown. Then I returned to the normal watering schedule. A few plants that I thought had died on me started re-growing from the underground tuberous root/stem. In fact, one seedling (the largest, which probably also had the deepest roots and could still access water) which didn't abort the old growth, still branched from underground as a result of the drying cycle I put the plants through. When I noticed the older rosette was starting to fade (just a slight change in color shade) and I was able to remove the older rosette and root it, cloning a tiny rosette only 1.5 cm wide. This plant is the Drosera capensis of Nepenthes!

While they have not yet entered the "long shoots" stage, I am starting to think this plant could be; or is very, very closely related to the true N. thorelii. The tendrils have been rather short, compared to the plant I have which doesn't match the type specimens of N. thorelii. The pitcher shape is rather close, much more so than the pitchers of N. anamensis, which are longer and thinner. Of course a lot more work has to be done, but this is a very interesting species/plant, and I rather doubt it is a hybrid based on Nong's description of how he found the plants and collected the seeds. He was certain these are a species in and of its self... If it is a hybrid, then it must be one where both parents have perennial, tuberous rootstocks.

[Marcello Catalano]

I found N. ampullaria last time, and also N. gracilis, but they just grow in the far south, where the climate is different, in typical ampullaria and gracilis habitats, so they don't experience the 6 months drought. And even if they grow a little bit more north, in a couple of cases, I'm quite sure they only grow where an always wet habitat is available, as it happens with N. mirabilis. I didn't check the roots, but I guess there was no need at all to have tubers: I always go there in the dry season and those two species had plenty of water around when I found them

N. mirabilis usually also grows in habitats that are wet even in the dry season, but sometimes I found it growing in apparently drier areas, where they were clearly suffering (like all the other tuberous species do, by the way) and probably catching some water from 10-20 cm deep in the ground.

It seems that droughts-suscettible areas are not even the factor that could have transformed mirabilis into vikings, as I've seen both growing in both conditions
But for sure I'll check the roots of those Trang viking-like plants, to make sure we actually found the missing link between the latter and the Phanga plants

Tubers seem to be present in ALL the narrow-leaved species, new species and already described ones. They are closely related in all senses, and the narrow shape of the leaves and the presence of tubers are the best strategies to retain water.
Marcello

[marka]

Apr 24, 2008 23:03:22 GMT -10 sockhom said:

Hi Michael.

I've heard that N. ampullaria can be found in Thaïland but my friend Marcello Catalano hasn't managed to locate it yet.
It would indeed be interesting to check the roots.

François.

I have an all red form from Khao Lak, I don't think the site exists now its been bulldozed apparently. It maybe far enough north, and its on the Andaman sea side, maybe it gets the same weather. Next time im re-potting ill look at the roots.

[sockhom]

Hello,

Here are some pictures of Nepenthes sp. Surat (Thailand) rootstock taken by Xir007 (thanks!):






lower pitcher


upper pitcher





François.