Tag Archives: green

Green slime mold

Plasmodial slime molds (class Myxogastria) come in many colors (yellow, purple, orange, blue, red), but rarely in green, so this find at a local park intrigued me. I found it February 23 under the bark of a decaying pine tree in Springfield, Pennsylvania. There were no fruiting bodies. 

I’m curious what species it is (let me know, if you know, please), but would love to know why it’s green. Here are three possibilities (I have more, if they fail): (1) the slime mold has formed an association with an algae or cyanobacteria, (2) the green pigment replaces the yellow pigment under some conditions, and (3) this is a species of slime mold that’s green but not frequently encountered so not part of books and online keys. The latter two are most likely, but the first was interesting to consider … see below if you have a few minutes.

Colin Purrington Photography: Slime molds &emdash; Green slime mold

(1) In regards to algal associations, I looked into this option first because the green appeared so exactly like that of alga. Of course, I’d never, ever heard of algal/myxomycetes symbiosis, so I looked into this possibility very, very quietly so people wouldn’t spew coffee out their noses. But I eventually found an article on the topic (Lazo, W. 1961.Growth of green algae with Myxomycete plasmodia. American Midland Naturalist 65:381-383). Here’s the summary from his abstract:

“Three species of Chlorella were able to enter into full associations with Physarum didermoides and Fuligo cinerea, forming green plasmodia in which the algae multiplied in light.”

The above association was under special laboratory circumstances, however, notably using slime molds that he’d purged of their bacterial partners with antibacterials. But even though the conditions might seem artificial, I suspect slime molds have a built-in ability to purge themselves (and surrounding substrate) of bacteria. And algae are easily found growing in soil and on dead trees, so it’s very likely that slime molds and algae come into contact in the wild regularly. And algae (or at least some species like Chlorella) can grow heterotrophically in the dark (e.g., on sucrose) and still remain green. This latter fact is important because I found this slime mold under rather thick bark, and I doubt it received any appreciable light. 

Indeed, some plasmodial slime molds appear to even specialize on the algal biofilms growing on wood (reviewed in Smith 2007). One mentioned by Smith is Barbeyella minutissima, which I Googled and found this:

“In addition to liverworts, Barbeyella is found socialised with monocellular algae. It is assumed that the protoplasmodium phagocytizes either the algae or the bacteria on their surface.”  — Global Fungal Red List Initiative

Smith also mentions that a Didymium iridis plasmodium harbored an alga (Trebouxia sp.) for months in a laboratory culture (Keller and Braun 1999; I couldn’t obtain to read).

So if the above scenario does occur, perhaps it’s similar to the trick noticed in some Dictyostelium spp. (cellular slime molds, in the class Dictyostelia), which known to carry around bacteria, which they can release onto substrates that are favorable for bacteria (i.e., they farm). 

Anyway, I don’t have a microscope to examine the slime mold for algae or cyanobacteria, so the above is just mere speculation. I suppose I could spray it with a good herbicide, but that’s seems cruel.

(2) The green color might simply be a pigment change. I don’t know much about myxogastrid pigments, but apparently moisture, light, starvation and other environmental factors all cause color changes. But I could find only a few papers discussing a green pigment. Here’s the best line from one of them:

“The yellow pigment of P. polycephalum has been found to be an excellent natural pH indicator (Seifriz & Zetzmann, 1935). In a neutral medium, the natural indicator is yellow, in an alkaline medium it is bright green, and in an acid medium it is deep reddish orange.” Seifriz and Russell (1936) [emphasis added]

[The citation of the referenced paper, which I couldn’t obtain in full, is Seifriz, W., and M. Zetsmann. 1935. A slime mould pigment as indicator of acidity. Protoplasma 23:175-179.]

The above fact is really interesting, but don’t know why a decaying pine log would become alkaline. I couldn’t find any good research on the topic, but perhaps I missed it.

The more interesting scenario is that a pigment gene is mutated. Mutations happen, though it’s rare enough that I don’t think it’s likely. 

(3) It’s of course most likely that there’s a species of green slime mold and I’m simply ignorant of its existence. Maybe it’s not even a slime mold.

(4) Or it could be oobleck

Some more pics:

Colin Purrington Photography: Slime molds &emdash; Green slime mold plasmodia

Colin Purrington Photography: Slime molds &emdash; Green slime mold


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Variable oakleaf caterpillar

This is a newly-molted variable oakleaf caterpillar (Lochmaeus manteo), with old head capsule still attached. I initially thought the capsule was the head and that the thorax had eyespots, but John and Jane Balaban on Bugguide.net pointed out the obvious to me.

This species sprays formic acid, apparently.

Colin Purrington Photography: Insects &emdash; Lochmaeus caterpillar

Close-up of Lochmaeus caterpillar

FYI, Al Denelsbeck posted an almost identical image here, complete with close-up of the eyes.

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Photographs from some local serpentine barrens — areas that are naturally toxic due to the magnesium, cobalt, nickel, chromium, asbestos, other nasties leaching out from the green serpentine rocks (California’s state rock). Serpentine soil is also famously low in phosphorous and potassium, so not many plants can grow on it.  Here’s a typical patch of rock (from Nottingham pine barrens in Pennsylvania):

At the Nottingham serpentine barrens in Chester County.

Below is a close-up of the rocks themselves.  I liked the central rock because of its serpentine (wavy, snakelike) marbling. From Pink Hill barrens at the Tyler Arboretum in Media, Pennsylvania.

Here’s a view of a serpentine barrens at Nottingham barrens.  If you were to take a close look at these pines, a lot of them have scorched bark from a recent prescribed burn that was conducted to restore native plants to the area.

At the Nottingham serpentine barrens in Chester County.

The flower below is moss phlox (Phlox subulata) at Pink Hill.  The plant is absolutely adorable.  I’m a sucker for any plant that assumes a moss-like habit.

Colin Purrington Photography: Tyler Arboretum &emdash; Moss phlox (Phlox subulata).

Below is a close-up of some sort of sedge, possibly Pennsylvania sedge (Carex pensylvanica), but I didn’t have any fruit so I can’t be sure (tentative ID courtesy Dr Roger Latham of Dr Roger Latham at Continental Conservation).  But I’m positive it’s adorable, though not mossy in habit.  Photograph also from Pink Hill barrens.

Richardson's sedge (Carex richardsonii), I think. Happy to be corrected.

More serpentine photographs here.

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Plastic is oil

Even though water bottles are often made of #1 plastic, quite a bit of oil is used (or burned) to make, decorate, fill, transport, chill, and recycle them.  (Energy details here, if you’re interested.)  And most people don’t recycle them.  If you are a fan of sustainability and a less-polluted world, you should stop using them except in emergencies (e.g., if you have a few cases in the basement for end days, that’s great).

plasticisoil, plastic is oil, water bottle, disposable, recyclable, energy, green, waste, garbage, environmentalBut everyone loves water bottles.  Some people use half-dozen per day.  So how to get people to question their addiction?  As a fun diversion, I designed the sticker at right.  The idea is to discreetly put them up at schools, workplaces, and stores, with the hope of slowly nudging people into ending their addictions to disposable plastic water bottles.

1. Download one of these two files:

2-image PDF for 4×6 sticker sheets
8-image PDF for 8 1/2 x 11″ sticker sheets

2. Print (I know, pretty obvious). I recommend Post-It printer paper (or equivalent) because it allows stickers to be easily removed by coworkers, bosses, police, etc. Similarly, using magnetic inkjet paper results in “stickers” that are perfect for refrigerators and beverage dispensers.

3. Attach onto water bottles at stores, or on shelving. Attach on counters at coffee shops. Etc…anywhere near where plastic water bottles are sold or handed out for free. And don’t get caught…bottled water is an $8 billion dollar a year business, so people who make money on this are rather fond of the scam.

4. If you have situated a sticker in a place that you think is just great, take a photograph and Tweet with the #plasticisoil tag. Or post a photograph and link back here. Or post a comment below with URL to photograph.

The above is probably futile, and potentially just a waste of sticker paper, ink, and associated printer and computer, but it seems that disposable water bottles are becoming more and more a ritual in peoples lives, and a little sticker shock might help alert a few people to how monumentally idiotic and wasteful they are. If you’d like to be better informed on the issue, please check out Inside the Bottle and Ban the Bottle.

Some colleges and universities have stopped selling/serving water bottles (article), and some stores have done the same (e.g., Mom’s doesn’t sell plastic water bottles anymore). But institutions and stores won’t just volunteer to do this … they need to be nudged, and agitation via stickers or other ploy will be needed to get people’s attention (I think).

Colin Purrington Photography: cute legs with green shoes &emdash;

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