Let the leafcraft continue. —MN
And so my dream of seeing a redwood as tall as the Burj Khalifa comes to a disappointing end. Still, the science behind the limitation is a pleasantly interesting consolation prize. —MN
Why trees can’t grow taller than 100 metres
TYPICALLY, the taller the tree, the smaller its leaves. The mathematical explanation for this phenomenon, it turns out, also sets a limit on how tall trees can grow.
Kaare Jensen of Harvard University and Maciej Zwieniecki of the University of California, Davis, compared 1925 tree species, with leaves ranging from a few millimetres to over 1 metre long, and found that leaf size varied most in relatively short trees.
Jensen thinks the explanation lies in the plant’s circulatory system. Sugars produced in leaves diffuse through a network of tube-shaped cells called the phloem. Sugars accelerate as they move, so the bigger the leaves the faster they reach the rest of the plant. But the phloem in stems, branches and the trunk acts as a bottleneck. There comes a point when it becomes a waste of energy for leaves to grow any bigger. Tall trees hit this limit when their leaves are still small, because sugars have to move through so much trunk to get to the roots, creating a bigger bottleneck.
Jensen’s equations describing the relationship show that as trees get taller, unusually large or small leaves both cease to be viable (Physical Review Letters, doi.org/j6n). The range of leaf sizes narrows and at around 100 m tall, the upper limit matches the lower limit. Above that, it seems, trees can’t build a viable leaf. Which could explain why California’s tallest redwoods max out at 115.6 m.
This technique is starting to pick up steam among artists with steady hands. Anyone have plans to grab an Xacto knife and follow suit? —MN
Install of waxed ginkgo leaves in peg board. I could probably fill up two peg boards with the amount of ginkgo leaves I have collected.
Couldn’t agree more. ~AR
Sit and watch some leaves. Have a lovely weekend, everyone! — Heidi
So, it turns out that botanical art isn’t limited to pine cone turkeys, or dried and pressed flowers. It’s fascinating—the amount of care and time put into preserving and repurposing each individual ginkgo leaf, despite the fact that millions of them fall around New York City each autumn. —MN
Here are some more waxed leaves. They are the next iteration of waxed leaves that are a bit more decorative, more detailed, and more time consuming. This is probably going to be one of the last times I can collect them because they are all decaying on the ground outside.
Some subdued autumn hues for you, and you, and you, in the vein of Hawthorne or Poe, or Hocus Pocus if you’re more for the Bette Midler portfolio. As we trundle toward winter, we’re spending every spare moment savoring the change of the leaves here at the NYBG. And thankfully, it’s only just beginning. —MN
Nature is fascinating, and some of Nature’s best work—or evolution rather—is illustrated by animals that have adapted to mimic leaves. Leaf mimics use an extraordinary type of camouflage to evade detection from predators or prey. These animals mimic leaves by using leaflike color patterns, modified exoskeletons, and cryptic behavior.
Downside to being perfectly invisible? You’re constantly getting stepped on. Though I don’t think there are many of these in New York for me to be worrying my conscience over. —MN
Leaf textures: rue, nettle, wormwood, motherwort and sage
Yes! Love this! Leaves are so often overlooked, in favor of flowers, but a good leaf is a thing of beauty. They have texture and heft; they have various surface treatments that make water bead and roll and run in rivulets; they have variations in color and pattern. Just watch out for those nettles, they have a whole ‘nuther thing going on, too. ~AR
After reblogging Adbusters’ “name that plant” illustration a little over a week ago, we found ourselves inundated with responses (well-informed and/or hilarious) by followers from all over the world. I think it might have been a point of pride to be able to tell the difference between a maple leaf and a palm frond. (Actually, I think that might just be me.)
Now that a sufficiently lengthy interlude of frustration has passed between question and answer, we finally have the resolution for those of you who were wondering what you were staring at with such rapt attention. To be doubly sure of ourselves, we asked Deanna, our Associate Curator of Woody Plants, to pitch the final word.
- Maple (Acer sp.)
- Hickory (Carya sp.)
- Douglas fir (Pseudotsuga menziesii)
- Oak (Quercus sp.)
- Birch (Betula sp.)
- Black tupelo (Nyssa sylvatica)
For that last one we’re going with a native tree, as Deanna informs us it’s neutral enough to be just about anything; consider it the freebie question on a pop quiz. (The artist here wasn’t exactly going for botanical art to be entered into a juried competition.) —MN
Looking at this beautiful slideshow from Garden Design Magazine of outdoor plants that you should try bringing indoors for the winter made us realize that foliage plants are, to many, the final frontier when falling deeply in love with gardening. It’s easy to get hooked on vegetables, and flowers are utterly charming. But plants that are grown simply for the foliage—that’s a bit of a harder sell. Do you love foliage plants? If so, what are your favorites?