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D. aliciae and black leaves from crown

jimscott

Tropical Fish Enthusiast
For the past 2 years I have noticed that my open tray D. aliciae plants start out blackened from its crown. Does anybody else experience this? What is causing it? The plants don't die and eventually stop doing that, I'm curious as to how and why.
 
I don't really see that in my aliciae plants but a lot of my Petiolaris complex Drosera do that. It took me a while to get used to originally because I would perpetually think the plant was about to croak--
 
Something like this?  Mine has done this for as long as I can remember. The plants are lush and beautiful regardless...

These first 2 pics were taken 12/14/04

aliciae1f.jpg


aliciae2f.jpg



This pic was taken today 12/17/06
aliciae1206.JPG


Full size pics:
http://steve.nightscapecreations.com/cppics/aliciae1.jpg
http://steve.nightscapecreations.com/cppics/aliciae2.jpg
http://steve.nightscapecreations.com/aliciaefull1206.JPG
 
My aliciae is doing that. The tentacles come out deformed/missing on those leaves. It seems to affect the smaller plants more than the larger ones. I thought maybe it was "damp-off", I tried swabbing a few leaves with a weak hydrogen peroxide solution with a water color brush. The black gunk washes off in some cases. It's actually a dark-reddish brown like iodine.
 
Never saw anything like that before on my D. aliciae.

Maybe due to too much humidy, poor air circulation?
rock.gif
 
Could be, mine is in a terrarium. I took off half the cover and positioned a fan so it gets some additional circulation.

This starting happening about a week or so ago.

I noticed the newest leaf on the biggest plant seems clear of the crust. I call it a crust because it seems to crack and flake off as the leaf develops. The leaves look exactly as the first picture above, with curled up tips and lack of tentacles.
 
Same thing happened to mine and I think this was due to a minor aphid infestation (which I quickly eradicated with some orthene). The leaves grew but always retained the black (dead) tissue and never completely uncurled. The new growth is fine.

I think it may just be a nonspecific consequence of plant stress (kinda like the "shrinking leaves syndrome" of stressed neps)!

Ken
 
I dunno, mine do something like this too, but it has never been a problem- I suppose I should record when I see it happening and see if there's some pattern, but once I saw that it didn't seem to "mean" anything, I kinda stopped paying attention
 
I wonder - could this be a form of minor dormancy? FWIR, these grow alongside capensis in the wild, and do experience a minor winter - and they can get snowed on.
rock.gif
 
  • #10
I was thinking that too. However the consensus seems to be it just goes away on its own so I'm not going to worry much about it and just let nature take its course.
 
  • #11
That's why I suggested I should log when it happens, as it does suggest a dormancy or sorts- since mine are all real happy looking right now, I assume the "black crust" happens in the summer (for me anyways) but if it were an attempt by the plants to avoid extreme heat by "cocooning" or something, black would be the wrong colour to use..

Hmmmm...

But as I said, it does NOT appear deleterious to the plants, and nothing changes in my set-up until the summer heat comes on (except for humidity going down a bit in winter, but it doesn't seem to affect anything too bad)

Good theory Schloaty, with some diligence we could maybe see if it holds up to some semi-formal testing
 
  • #12
repotting my aliciae into a nice, big, new pot solved the problem for me..
 
  • #13
I noticed earlier that the backs of the new leaves were getting darker green/brown streaks on the backs and gotten a little hairy - streaks and hairs parallel with the long axis of the leaf. The leaves formed normally. Then about a week or so ago the crowns were coming out black.

You can see the streaks in some pictures of aliciae that others have posted.
 
  • #14
[b said:
Quote[/b] (vft guy in SJ @ Dec. 17 2006,5:17)]Something like this?  Mine has done this for as long as I can remember. The plants are lush and beautiful regardless...

These first 2 pics were taken 12/14/04

aliciae1f.jpg


aliciae2f.jpg



This pic was taken today 12/17/06
aliciae1206.JPG


Full size pics:
http://steve.nightscapecreations.com/cppics/aliciae1.jpg
http://steve.nightscapecreations.com/cppics/aliciae2.jpg
http://steve.nightscapecreations.com/aliciaefull1206.JPG
Yes, that's exactly what I have been experiencing! Thanx!

Mine is sitting, along with a bunch of other sundews, in a plastic storage container, open tray, with a fluorescent light over them. Happens only in the winter.

It can stand for being in a larger pot.

It's the ONLY sundew doing this.
 
  • #15
my aliciae does it as well, dunno what it means. mine isnt exactly the healthiest sundew either =(
 
  • #16
[b said:
Quote[/b] (jimscott @ Dec. 19 2006,8:33)]Yes, that's exactly what I have been experiencing! Thanx!

Mine is sitting, along with a bunch of other sundews, in a plastic storage container, open tray, with a fluorescent light over them. Happens only in the winter.

It can stand for being in a larger pot.

It's the ONLY sundew doing this.
Open tray means not in a terrarium? I wonder if it is a "dormancy" thing. What are your temps like?

Mine are in an unheated terrarium, fluorescent lighting. Temps have been dipping down to the mid-low 60's at night and high 60s low 70's during the day. I normally do not heat the room the terrarium is in until the room temp dips to the low 60's. Today was the first time I turned on the heat (about 68F).

A black coating would absorb more heat from solar energy so maybe they do that to try to warm up???
 
  • #17
I don't think this species requires a dormancy. Temps are right around 70, very stable. Lighting is ~15 hours per day, under a fluorescent light, since November. And now the next leaf opening up is perfectly normal. Go figure....
 
  • #18
i'd like to get it under a microscope...

my aliciae does the same thing.
 
  • #19
<span style='color:red'>This is something that was reported on, I believe, back in the 1970's. Here is a short description of the issue.</span>

<span style='color:darkblue'>The darkening of the growth point, as shown by the photographs shared here, is caused by humic acids, and perhaps other solubles, wicking up and depositing themselves, first on the hairs and stipules of the leaf primordia, eventually covering the entire surface of the growth point and leaf primordia. My experience is that this can have a damaging effect on the growing point and can supress new growth. The easiest way to reduce this is to gently provide overhead watering with warm, purified water as often as necessary to reduce this precipitate. Another solution would be to use less peat moss, since it is a strong source for the most offending compounds, though other media ingredients may also be sources. It is also affected by temperature, ambient humidity, air movement, etc.</span>
 
  • #20
Great info! It makes sense because it seems to start out as darker green/brown streaks which would be the compounds wicking up the leaf structure. And as I noted before the stuff washes off.

So gentle top watering with warm purified water will help. Changing the tray water afterwards will probably help to remove the compounds from the system too.

This would explain why it goes away in time as either the compounds accumulate on the (eventually) dead leaves or is leached out of the potting media in time from watering.
 
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