Drosera rotundifolia - southern most populations / warm-grow

[sundewmatt]

What's the southern-most Drosera rotundifolia population anyone here's been to or has plants from? I'm looking for a rotundifolia which will appreciate warmer conditions and which will either not go dormant (wishful thinking, I know!) or possibly withstand warm winters. Does anyone have any suggestions? Please don't say "rotundifolia Evergrow" - I'd like to find a wild form. Schnell's book shows it growing south to Georgia - does anyone know if this is a mountain population? Also, I wonder what the min and max temperatures are for the southern-most rotunds in Japan, and where else they might occur where they could experience warm temps. Anyone?

Thanks,

Matt

[Khelljuhg]

Wouldn't it be D. rotundifolia from Kagoshima pref., Japan?

Here are the averages of the highest and lowest temperatures of the past 5 years in Kagoshima, just for reference.

the highest: 35.7 degrees Celsius

the lowest: 0.8 degrees Celsius

[sundewmatt]

Thank you for the suggestion. Maybe this is a possibility. I found this online regarding this location:

CLIMATE: Station #47827, Kagoshima, Kyushu, Japan, Lat. 31.6N, Long.

130.6E, at 19 ft. (6 m). Record extreme temperatures are 97F (36C) and 20F

(-7C).

N/HEMISPHERE JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

F AVG MAX 53 54 60 68 74 78 85 87 83 75 65 56

F AVG MIN 37 38 43 52 58 66 73 74 69 59 49 40

DIURNAL RANGE 16 16 17 16 16 12 12 13 14 16 16 16

RAIN/INCHES 3.4 4.0 6.4 8.7 8.2 17.1 12.2 7.4 8.7 5.2 3.7 3.4

HUMIDITY/% 76 73 74 77 79 82 82 80 80 76 77 77

BLOOM SEASON * * ** ** ** * * * *

DAYS CLR @ 9AM 9 8 9 7 5 3 4 9 9 12 14 13

DAYS CLR @ 3PM 8 9 9 8 5 3 5 6 6 13 13 13

RAIN/MM 86 102 163 221 208 434 310 188 221 132 94 86

C AVG MAX 11.7 12.2 15.6 20.0 23.3 25.6 29.4 30.6 28.3 23.9 18.3 13.3

C AVG MIN 2.8 3.3 6.1 11.1 14.4 18.9 22.8 23.3 20.6 15.0 9.4 4.4

DIURNAL RANGE 8.9 8.9 9.5 8.9 8.9 6.7 6.6 7.3 7.7 8.9 8.9 8.9

S/HEMISPHERE JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN

So it appears as though it is used to experiencing temperatures near freezing. I was hoping to find one which won't go dormant in my conditions.

Do you know how this population grows during the hot summer months? In populations near m, plants do not look very good during the heat of the summer.

Thanks,

Matt

[Khelljuhg]

I feel that it is difficult to find a population with no winter dormancy in the wild, but it may be easier to grow a population from a warmer area.

I suppose that the form found in Kagoshima should have more tolerence against high temperature because there it is very hot in summer...

OK I will ask a CP grower in Kagoshima.

[sundewmatt]

Please let me know what your friend in Kagoshima says.

This Japanese rotundifolia looks very nice - much better than the ones I have seen in New Jersey and New York, USA:

http://www-cp.stech.co.jp/cp/img/habitat/m...undifolia13.jpg

It's from Ueno Area habitat/Mie-PRE,JAPAN(Pacific Ocean side Central of Japan)

[Fernando Rivadavia]

(posted on CP listserv, regarding a possible D.rotundifolia collection from New Guinea...)

--------------------------

Hi Matt,

> I see references to Irian Jaya with it's "perpetual snow cap". Something

> makes me think this may not be a heat tolerant one.

The CP Database mentions it was found at: Wissel Lake area near Arupa, Snow Mts., Western New Guinea. Unfortunately no mention of altitude is made. Nevertheless, I believe it does serve your purpose...See if you agree with this brainstorm:

First thing to remember is that New Guinea is almost smack on the equator. Therefore, there will be no winter/ summer as you people in high latitudes know. This means that NO Drosera species can live up near the perpetual snow cap because it would be snowy all year long. Even if the snow melts and recedes a bit during the dry season, it would probably still be too cold for a Drosera to survive.

Therefore, it almost certainly does not grow near snow in perpetually intense cold weather. At max we'll see a wet/ dry season and therefore a dry dormancy for this Drosera (if any). This is enough to make it VERY distinct from any other D.rotundifolia...

My guess is that this Drosera grows at medium altitudes, where it's perpetually cool, simply because lower down (where it's perpetually warm or hot) it's probably less likely you'll find open habitats suitable for Drosera. Maybe something like highland Drosera on Venezuelan tepuys. I think this would be interesting habitat for a D.rotundifolia, no?

See ya,

Fernando Rivadavia

[Fernando Rivadavia]

Hi Matt,

After writing all the last e-mail, I googled Wissel Lake, found a

few references, and then found the exact spot with the help of Google maps.

The satelite picture shows lots of clouds, but no perpetual snows around the

lake. In fact the highest peaks in New Guinea (as well as perpetual snow it

seems) are found on the eastern part of the island, and not in the west

where this plant was collected. The altitudes I found for Wissel Lake are

approximately 1650-1750m.

I guess the main question is: **IS** this plant from N.Guinea truly

D.rotundifiolia? Considering the probable habitat of this plant (discussed

in my previous mail), I'd say no.

It would be very interesting if somebody could take a look at this

herbarium specimen again (and pics too for all of us to see!!). It was named

D.rotundifolia subsp.bracteata and is deposited at the Nationaal Herbarium

Nederland, Leiden University (Netherlands). Any volunteers??????

Best Wishes,

Fernando Rivadavia

[Khelljuhg]

Well, I have received an answer from the grower in Kagoshima. He says that there are a few types there, one of which has tolerance against the summer heat and has shorter dormany in winter. He has told me that he is going to visit the habitat soon.

The CP Database mentions it was found at: Wissel Lake area near Arupa, Snow Mts., Western New Guinea.

New Guinea?! I have no idea what the Drosera is, but if it is D. rotundifolia, it must be remarkable.

[sundewmatt]

Hi Fernando,

Thanks as always for the input. I agree that if this plant from Western New Guinea is in fact rotundifolia, it would be a really interesting plant to check out, but I'm not so convinced that it would be a good candidate for _general_ cultivation where temperatures can get hot - what I was looking for is really a rotundifolia which doesn't "crap out" during the heat of the summer.

Even if there's no snow where it grows, if the WNG rotund is used to cool temperatures year around, it may not be such a good candidate. I should point out that the CP database location is Wissel Lake area near Arupa, _SNOW_ MTS, the keyword being ____SNOW____, so I'd think there must be snow somewhere close by... The lack of collections in other tropical latitudes suggests to me that rotundifolia isn't capable of surviving in a location without a cold dormancy. I think it might have lucked out and found a habitat there which isn't too different from what it's used to in the N Hemisphere, probably at a high elevation. Now, this is all speculation, and I don't like to speculate but am doing it just to be polite and continue this thread. ;) For all we know, this could be D.petiolaris. Back in the day (and even to this day!), it seems uninformed botanists had a habit of labelling every Drosera they found whatever common species they were familiar with from their part of the world. Doesn't rotundifolia grow in the Netherlands? And wait a second, doesn't a certain friend of ours live there? Maybe he could take a pic of that specimen... I'm really curious too.

I also seem to recall that although Venezuela is just about as close to the equator, doesn't the - STILL (ehem) mysterious - Drosera cendeensis (which appears to me to have a dormancy period) grow at high elevations and maybe even experience a cold, snowy season? Or am I getting this wrong?

Getting back on topic, regardless of my skepticism, if anyone's out for a stroll in Western New Guinea (hmmm, didn't I just chat with someone who knows someone who knows someone in NG? - you reading this?) :) they should certainly collect some seed and get it into the hands of whoever has the best conditions for it. Just watch out for them cannibals, especially the ones with sharp teeth. :)

Oh, one last thing. The "Drosera intermedia Cuba" which has been floating around in collections is a small form of this plant which I consider to be an underperformer in cultivation, in my conditions at least. Our good friend Ivan liked it in the past because of the short amount of time it takes to go from seed to flowering - he used it in some of his hybridization experiments for this reason. This plant, although it's supposedly from Cuba, still forms a hibernaculum and for this reason and the fact that it's a puny little thing, is therefore, from my perspective, a much poorer candidate for cultivation than the larger plants from S.America which don't go dormant. I'd even say that the form from N.Carolina ("giant" which I got from W.I.P. in the 80's was a much, MUCH better grower than "Cuba" in my collection. Anyone know who collected this plant and where in Cuba it came from / what elevation?

Thanks,

Matt

PS Wasn't it so much better back in the day when we only had to post these discussions to ONE place? :*(

[sundewmatt]

Hi Khelljuhg,

This is exciting news!

When I saw that photo from Mie-Pre, I just KNEW that plant had to be a good grower.