Flowers are easily the most variable organs of flowering plants (hence the name), and botanists are interested in the mfor a variety of reasons, not least because of their value in systematics (my field). The great diversity of floral forms makes for lots of information as to what plants are closely related. A lot of work has been done in genetics on what determines the identities of the organs in a flower (why one the flowers of one species have both male and female reproductive parts while others have only one or the other, for example). More recent work has begun to focus on how the shapes of flowers are genetically determined, and more specifically, their symmetry. But what do botanists mean by 'symmetry'?
Arabidopsis thaliana (pictured) is the dry erase board of plant biology; which is to say it's a good model organism. We know a lot about it, not because it's particularly useful or interesting to humans, but because it's very easy to study. It has a short life cycle (six weeks), it's allegedly easy to grow (although I, personally, suck at it), you can grow a lot of it in a very limited amount of space, it has a small, fully-sequenced genome and it self-fertilizes. A paper published in last week's Nature explores how Arabidopsis' capacity for self-fertilization evolved.
Today is the 185th birthday of Thomas Henry Huxley, pioneer in animal systematics and comparative anatomy. He was known as Darwin's Bulldog for his spirited, passionate, often sarcastic and witty defence of the latter's theory of evolution by natural selection, which the reader may be familiar with. In fact, of all Darwin's contemporary defenders, Huxley is widely considered to be the hottest.
Please form one line, no pushing.
I will admit that Pharyngula's Botanical Wednesday feature today induced a kind of a panic attack that only a botanist can have:
Couroupita guianensis, the cannonball tree
See that big, pink, sea-anemone-looking structure just kind of floating there? Well that's (1.) some sort of biological structure that's (2.) apparently part of a plant and (3.) I don't know what the hell it is!
Posted by Dioscorides on Wednesday, April 28, 2010
Lignin is a rigid, waterproof polymer found only (as far as I know) in plant cell walls. It's pretty interesting stuff: it's what makes trees rigid enough that they don't fall over and gives the water-bearing vessels in plants the ability to withstand large tensions without caving in. It's also inedible, at least to animals, and is sometimes used as a defensive compound. Because it's of economic significance (high-lignin wood makes good building material and fuel, but bad paper) a fair bit is known about it biochemically.
Why do I, an evolutionist, care? Because of this cool paper recently published in Plant Cell.
In 1790, the German poet J.W. von Goethe introduced the hypothesis that all the parts of a flower are derived from modified leaves. On this view, the sepals (the green, sheathing structures on the pink pictured above) and petals of a flower are leaves which surround the reproductive parts, usually with the goal of attracting insect pollinators, with an optional dose of attractive pigment. The stamens (male reproductive structures) are leaves which have developed specialized pollen-producing organs. The stamens in the water-lily pictured (the yellow structures) are more or less leaf-like, and it is easy to see how they might have developed from a primordial leaf. But where are the leaves on a pistil?
Hello internet! I'm a plant nerd with designs on grad school and one year left on my BSc in evolutionary biology. My plan is to write on various topics of interest to me in plant biology, with a focus on my areas of specialty: systematics and comparative development. The goal is to improve my science writing and natural history chops, hopefully while being slightly interesting.
I should post a real article within a few days. Stay tuned!
(My title, by the way, is cribbed from this excellent, if outdated, book by E.J.H. Corner.)