Category: Diversions

Mystery pits revealed

I’d turned Friday’s picture on end to try to fool you…but to no avail.  Deirdre and Gail both guessed woodpeckers, and yes, this is sapsucker damage:

Though some woodpeckers look for insects under the bark, sapsuckers drill neat lines of wells that fill with sap.  The birds can then move down the line of wells, lapping up sugar water.  (Kind of the avian version of lining up tequilla shots on the bar.)  Healthy trees are generally not at risk of dying from drilling injury, though if the tree is completely girdled that would be a problem.  Trees stressed by other factors could be also be killed by this final straw.

(Deb and @s both thought the photo might be a cactus skeleton, and it certainly looks like one!  Hadn’t thought of that myself.)

Quiz answers – more or less

I just got back from a 9 hour overseas flight, just in time to post the answer to last week’s quiz.  So now you know…I wasn’t in the states.  More on that later.

As many of you guessed, this is a fig tree (Ficus spp.) of some sort.  I have horrendous taxonomic abilities anyway, but will cover my ignorance with the excuses that the tree wasn’t in flower, nor were there any signs in any of the little parks identifying the tree.  So we can continue to speculate on what species this is.  I do know it’s quite an old specimen, and that there are some Ficus native to the region, but past that I’m clueless as to whether this really is a native species or not.

And where was this huge tree?  In Alicante, Spain, where I spent a few days visiting my daughter who’s studying there this semester.  (Non-scientific aside:  I would go back there in a heartbeat.  If you are looking for a Mediterranean tourist destination that isn’t overrun with Americans, this is the place to go.)

Finally, these cool wavy woody structures are buttress roots, as Jospeh, Shawn, Rotem and Deb all pointed out.  They have both a structural and storage function: like all woody roots they store carbohydrates, but the over-developed flare helps support the tree in thin soils (like here) or in wet, low-oxygen soils (like those where mangroves grow).  In both cases roots can’t reach far enough below ground to stabilize the trunk, so the buttressing serves that function.

@Rotem also noted that branches can root and support the tree.   While the buttress roots in the original photo arose from root tissue, you can see examples of the rooted branches in the photo above.

And I do love the less-than-serious answers some of you kindly provided for our amusement.  Fred’s "rumble strips for drunks" was particularly apropos, since my last night there was one big street party after Barcelona beat Manchester United in the Champions League soccer match.  My daughter and I ended up in our hotel elevator at 8 am the next morning with a fan with no pants.  We did not ask.

Three part plant quiz

I’m out of town this week, and taking lots of plant pictures.  Here’s an interesting tree, quite common in the city where I’m staying:

Question 1:  What kind of tree is this?  (Genus is good enough – species might be hard to tell.)

Question 2:  In what geographical region might I be staying?  (The tree is native as far as I know.)

Question 3:  What are these woody structures called, and what function do they play?

Answers next week!

Answers to blue flower quiz

Paul, Joseph, Kandi and Derek are all, apparently, Puya fanciers.  But!  It’s not P. alpestris, but P. berteroana – a species whose flowers are more turquoise than sapphire:


Yeah, Kandi, check out those spines!  Even taking pictures is deadly!

And Paul and Joseph were correct – the long green structures are sterile (they bear no flowers) and serve as bird perches.  The nectar almost runs out of these flowers, and as the birds get a sugar fix their heads are covered in pollen.

Thanks to Paul Licht, Berkeley Botanical Garden Director, for my short but fabulous tour that included these beauties.

Bt in the Bloodstream!

Over at my favorite blog (besides this one of course!) Garden Rant, Amy Stewart posted about exploding watermelons — which Linda blogged about below — and about how Bt from genetically engineered food had found its way into our blood stream (and the bloodstream of unborn children).  Sounds pretty scary doesn’t it?  I’m not going to tell you it isn’t a little troubling, because it is, and I absolutely do not think this finding should be disregarded.  But the truth is that I’m not too worried about Bt in the bloodstream for the following reasons:

1.  The world’s ending on Saturday anyway, right?

2.  It’s impossible to tell from this study where the Bt toxin came from — I do think it probably came from transformed crops — HOWEVER, as scientists we can’t make that assumption.  We eat Bt all the time EVEN IF WE EAT NO TRANSGENIC CROPS because this bacteria is found all over the place.  I would have liked to have seen testing between people who eat transgenic food and people who eat no transgenic food.

3.  The Bt toxin is extremely specific in terms of what it affects in an insects gut.  It’s unlikely (but not impossible) that it would react with anything in our bloodstream (or an unborn child’s bloodstream).

4.  There are arguments over whether transgenic crops are sprayed more or less than than non-transgenic crops — but for insect control transgenic crops are generally sprayed less — and non-transgenic crops are sprayed with some seriously nasty stuff including nerve toxins.  If I get to pick my poison I’ll go with Bt any day.

5.  As a rule you should NEVER worry until a second study confirms the findings.  This paper is important enough that you can be sure that within a year someone else will try something similar.  If the findings hold my concerns will increase somewhat.

6.  Finally, the dose makes the poison.  Bt has been fed to various mammals for years to determine the effects that it has on them — and it generally has little effect, even over long periods of time.  These animals, obviously, had the toxin in their blood (just because it wasn’t tested doesn’t mean it wasn’t there).

It should be no surprise that when we eat something with a toxin in it, that toxin gets into our blood.  When you eat garlic — toxins from the garlic get into your blood.  When you eat hot peppers — capsaicin (an insecticide) gets in your blood.  When you drink alcohol — you get the picture.  Is it bad for things to be in the blood?  It depends entirely upon the thing and the concentration.  This article talked about fetal issues so lets use a fetal example — Aspirin is considered a bad idea during pregnancy — it can get into the unborn child’s bloodstream.  However, low doses of aspirin can reduce risks of pre-eclampsia.  By the way, a chemical very similar to aspirin is also known as a fungicide….(actigard).

So, there are my reasons for not being too worried.  Could I change my mind — YES.  Could I be wrong — YES.  BUT as a scientist who reads a lot of what I’ll call “reactionary/radical articles” I have my doubts when I read about the next thing that’s going to kill us all.  If we responded to every troubling article we’d never leave our houses.  BUT there’s always that one important article that warns us about something real — and we need to be on the lookout for it.  My reaction to the Bt threat — this isn’t it — but time will tell whether I’m right or wrong.

When Trees Don’t Know They’re Dead.

Last week a neighbor of mine called me up to ask how likely it was that their 4 year old (or so) crab apple tree was dead.  Sometime over the course of the winter cute fuzzy bunnies had decided that the tree’s bark was tasty and decided to eat it.  Naturally they ate it all the way around the circumference of the tree with the exception of a strip about an inch wide.  At this point you’re probably asking yourself why the neighbors suspected the tree might be alive.  The reason they were calling me was that the tree was leafing out–  so they figured that maybe the tree would make it — that maybe, just maybe, it wasn’t as bad as it looked.  My answer — Sorry, the tree is dead, it just doesn’t know it yet.  As a rule of thumb you can have up to a third of the circumference of a young tree girdled and the tree has a decent chance of growing out of it.  More than that and, though the tree might live for a few years, you’re dealing with so much damage to the vascular tissue that you’re just putting off the inevitable by not cutting it down.  A tree with as much damage as my neighbors tree had was just going through the motions.

When bark is eaten what is destroyed is the phloem — the tissue which carries the carbohydrates made by the leaves down the plant’s stem.  The cambium — which creates new phloem and xylem — is also destroyed.  But the xylem — the innermost tissue which transports water and nutrients up the stem — is left largely intact.  So girdled trees will flush out in the spring (using resources provided by the xylem), perhaps even two springs, but ultimately the tree will succumb.

But there is an up-side!  Girdled trees will be under a lot of stress.  Stressed trees tend to flower heavily — so enjoy the show first, then cut down the tree.

Solution to Friday’s flower fuddlement

Ed and Gayle correctly pointed out that short day plants (those that bloom in the spring or the fall) can sometimes do both.  The asters probably experienced some transplant shock in the fall, which would have suspended floral bud development.  This phenomenon could also be due to mild winter conditions (as Ed and Gayle also mentioned), which could have spared flower buds normally killed by freezing temperatures.

In any case, as spring daylengths approached those found in the fall, flower development continued and voila!  Asters in the spring!  Likewise, there are a number of spring bloomers that sometimes have a second (usually reduced) floral display in the fall.

Thanks again to Ginny for sharing her photographs and information!