Posts Tagged 'galls'

Galls

You may know of my fascination with galls, the structures created by plants in response to insects. In the Botanisk Have in Copenhagen and in the Alnapsparken at Sveriges Lantbruksuniversitet, the Swedish agricultural college, I found these lovely knopper oak galls. They were growing on acorns of Quercus robur, the great oak of Europe, which we usually call the English Oak (cf. hearts thereof), but when in Rome, or more specifically Sweden, it’s skogsek. It is, of course, thanks to a Swede, one Carl von Linne — the family name comes from the lime (linden) trees on the family estate — who is better known as Linnaeus, who codified the binomial naming system that is supposed to be universal. So the full binomial for this oak is Quercus robur L., the initial standing for the namer, yup, Linnaeus. One of L.’s students was the founder of the precursor institutions of the SLU.A gall wasp, Andricus quercuscalicis, causes these oaks to form these when they lay their eggs on the emerging acorns. These wasps need Turkey Oaks (Quercus cerris L.) to complete their life cycle, so finding them in botanical garden settings makes a lot more sense then finding them out in the “wild,” where these other oaks are a lot less common (Q. cerris is native to southeastern Europe and Anatolia/Asia Minor).

Galls like these are full of tannin, a gallic acid which has been used for centuries as a component of iron gall ink. The Magna Carta, Beowulf, and the Lindisfarne gospels were all written in this stuff, which is made from the galls (Oak Apple galls in these cases), iron sulfate, and water.

Galls

A tell-tale growth. Turn the leaf over.The gall of it all! I am fascinated by these things. Galls are created by the plant in response to the agitation of a wasp, mite, or something even smaller. For instance, insects lay their eggs on or in the plant, the plant is stimulated to build up over the eggs. It is a process of containment and isolation. For the gall-forcer, it’s protection and food. The eggs will hatch out to larvae in the gall. The critters will find themselves inside a plant! And that, of course, can be eaten.Eventually the critters will emerge, boring out, unless something gets them first. This one looks like it may have been opened up by a predator. A bird?

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Another kind of gall: as a crime family, the Trumps have long connections with mafias of various sorts. Bloomberg on the Russian criminal front.

 

 

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Oak Galls

gall1The mighty oaks and their galls are an endless source of curiosity. This particular type, a hard, fruit-like structure, is created by a tiny wasp, which essentially irritated the tree into making them for their larva.
galls2Clever boots! The trees are Swamp White Oak (Q. bicolor), according to the Street Tree Map. (I’m waiting on some leaves to see if I can confirm that.)gall3The wasp’s exit hole. I think these are Disholcaspis genus gall wasps. D. quercusmamma perhaps? (Why, yes, a translation of that would be “oak breasts.”)

Spiny Gall

gall2Witch-hazel (Hamamelis virginiana) is a good gall-tree. One species of aphid, Hormaphis hamamelidis, forces the tree to make cone-shaped galls on the leaves. The young aphid grows up inside this, protected from its enemies. Another species of aphid, the Spiny Witch Hazel Gall maker, Hamamelistes spinosus, makes the tree make these hard, spiny galls that come off of the twigs.gall1Ken Chaya, who identified these for us, cut a couple of them in half. A spider had taken up residence in one. Another had the white filaments of a cocoon within.
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Have to admit missing most of the White-tailed-Deer-in-Harlem story, for I have no interest in television news ratings-fodder. In response, Jason Munshi-South had a good editorial in the Daily News on the need for a sane policy on urban wild animals.

Wool Sower

wool1Galls are some of the most fascinating things found on the planet. At least in my opinion. wool2And this is one of the most spectacular. This is created by a tiny gall wasp, Callirhytis seminator, the Wool Sower Gall (-maker). But of course that is a mis-leading statement. The gall is actually created by the plant, in this case an oak, in response to irritation/agitation/chemistry of the wasp. The wasp is warping the plant’s defenses for its own uses, protecting its eggs and feeding its larvae. IMG_7184

These were discovered at Fort Nonsense Park, site of a Confederate earthworks to defend slavery, in Mathews Co., Virginia. But we also have them up here in Brooklyn.

Hedgehog Galls, Ladybug

gall1According to my own personal memory device, this is the third year I’ve noted these hedgehog galls on this White Oak (Quercus alba) in Green-Wood. This year there is a bumper crop of them.lady3A Multicolored Asian Ladybug (Harmonia axyridis) on the galls.

White Oak

Quercus albaThe pale underside of some Eastern White Oak (Quercus alba) leaves found on Mt. Taurus.Quercus albaThis is another specimen of the tree, two weeks later, in Green-Wood. It’s been a spectacular fall. Q albaSame tree, with some Hedgehog Galls. I also explore these fuzzy galls a little more here.


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