Five plants that nodulate with nitrogen-fixing bacteria

Hooray! Here they are, my lovely nodulating pals, this year's work. It's on show now until the 28th September 2014 at RBGE :

Acacia cornigera (L.) Willd.  - bull's horn acacia.

Lathyrus vernus (L.) Bernh.  - spring vetch.

Strongylodon macrobotrys A. Gray - jade vine.

 

Myrica gale L. - bog myrtle.

Hippophae rhamnoides L.  - sea buckthorn.

I'll maybe say a bit more about these later, but right now I'm going to sleep.  Goodnight, and thank you all.

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It's all stamens and no style.

Here's a picture of home studio corner today.  Note the fabulous jug of Goo, which had contained my bog myrtle specimens in some sphagnum and peaty muddy water so it would feel at home -  had to take the specimens out to dry out but I can't bear to throw out the substrate in case there are marvellous life forms lurking in there.

Anyway today we're looking at the flowers of the marvellous Vachellia cornigera or Acacia cornigera or bullhorn acacia . There's my specimen in a jar behind the paintbox.

So the nice yellow rockets are the inflorescences, and each of these individual tufts is a flower. Hundreds of them.

Very very small, and slightly sticky, though inclined to jump into outer space if you come at 'em with a scalpel. Can't say I blame them.

Thing is, there are hundreds of the male parts, but I'm buggered if I can find the female parts. Look! And that's the tip of my scalpel blade there, so you get a sense of how big they are.

That little brown effort there at the top is some sort of dysfunctional ovary, I think....

and finally, a wee pod.  I went through a large part of that inflorescence and only found five or six amongst a hundred or thereabouts, whatever is going on there probably accounts for the very small fruit to flower ratio - you can see the fruits on this herbarium specimen from Kew.

Some jolly sketchbook guff for your viewing pleasure. I got very interested in thosesmall brown cups in between the flowers, I think they are probably trichomes of some sort. They start out as fishy scales covering the flower buds;

and persist on their stalks as trumpet-shaped structures after the flowers fall off.

The first attempt at a posh version of the dissection. I used a dip-pen with paint in it for the fine lines, which just weren't fine enough.

Traditional tiny paintbrush fared much better in the second attempt. Also ultramarine violet for darkening the yellow, very nice, made for lovely soft granular greys.

Soundtrack for today is TWiM #73: Eyeing Root Nodule Development , delightful to listen to although a bit disrupted by the Leith Emergency Services Symposium: "Coping with the Consequences of Poverty, Discrimination, Disenfranchisement and Alienation" which takes place outside my window every now & then. Happily I think everyone walked away from this one.

Biting and chewing

Sometimes I feel like I have bitten off more than I can chew. Lovely acacia! But so many leaflets!

 

Here's a look up through the leaves of the real thing. The deal is, the thorns are a home that the tree makes specially for its symbiotic ant-friends Pseudomyrmex ferruginea.

The warty structures on the stem of the leaf here are extrafloral nectaries, with a special recipe of nectar for the same ant species. In addition to this sugary treat the tree provides the ants with a delicious proteiny fatty snack, the Beltian body - the yellow jobs on the ends of the leaflets here. In return for this luxury hospitality the ants protect the tree from hervivores, attack any vines thet come within spritting distance of the tree and generally weed out all the competition from around the tree. If you want to see really good photos of  Pseudomyrmex ferruginea (or any other ant), have a look at Alex Wild's photography.

Here's Pat Clifford at RBGE heroically lifting slabs in a search for nodules, hardly anything at all, a bit disappointing but there were one or two which is enough to be going on with.

Herbarium heaven

This is my new favourite place to be, the herbarium at RBGE. It's like a library only it has thousands of dried plants in it. And microscopes.  And it is quiet and climate controlled.

Like many libraries, anyone can use it, all you have to do is email the nice staff and tell them what you want to look at.

Here I'm looking at an Acacia cornigera that was collected from Tobago in 1909. I'm enjoying the strange and very direct connection to the cultural histories that these dusty old labels have too.

The plan is to make a lovely Botanical Illustration of this plant....

As for the specimens themselves, I think they are magical. Rachel Pedder-Smith has lots of interesting things to say about herbarium specimens in her thesis. She considers the specimens as objects, as well as plant material subjects. I realise I am thinking of them more as sort of toenails - discarded parts of living beings - and of the human agents who use them as the sort of witches that go around gathering bits of people in order to do magic on them. Or maybe saintly relic sorts of things. Something slightly more animated with its own self rather than solely by the human interactions with it, at any rate, albeit rendered extraordinary by being seen through a special human prism. I haven't  finished thinking about that so I'll say no more for now, given the risk of deteriorating into talking Pure Balls.