< Back to front page Text size +

Reading the Leaves

Posted by Josh Rothman  September 22, 2012 09:44 AM

E-mail this article

Invalid E-mail address
Invalid E-mail address

Sending your article

During the spring and summer, we pay attention to flowers; during the fall, we pay attention to leaves. Just in time for autumn, Rob Dunn has written a fantastic essay about leaves for National Geographic magazine. The shape and structure of a leaf, Dunn writes, can reveal a lot—about the climate it’s designed for, the evolutionary history of its species, even the size and vitality of the plant to which it belongs.

Photo: Jon Sullivan.

Different kinds of environments, Dunn explains, push evolution to favor different kinds of leaves. Rain-forest plants, for example, tend to have long, narrow leaves with “drip tips” on the end, to help drain away the deluge. If a plant shares an ecosystem with lots of leaf-munching animals, then, over evolutionary time, the textures of its leaves may change. “Grass blades,” Dunn writes, “evolved the ability to accumulate the silica from the soil—becoming like tiny glass slivers, which ruin the teeth of browsers like cows one bite at a time.”

The veins that line a leaf are a clue about the plant to which it’s attached. The veins carry water to the plant’s chloroplasts, the intra-cellular organs that power photosynthesis. The more water a leaf can transport, the faster it can photosynthesize; that, in turn, allows the plant to grow faster and higher. The more veined a leaf is, in other words, the bigger and taller its plant is likely to be. That’s why, Dunn writes, the veins of a maple leaf are “like the roads of a city.”

This blog is not written or edited by Boston.com or the Boston Globe.
The author is solely responsible for the content.

E-mail this article

Invalid E-mail address
Invalid E-mail address

Sending your article

About brainiac Brainiac is the daily blog of the Globe's Sunday Ideas section, covering news and delights from the worlds of art, science, literature, history, design, and more. You can follow us on Twitter @GlobeIdeas.
Brainiac blogger Kevin Hartnett is a writer in Columbia, South Carolina. He can be reached here.

Leon Neyfakh is the staff writer for Ideas. Amanda Katz is the deputy Ideas editor. Stephen Heuser is the Ideas editor.

Guest blogger Simon Waxman is Managing Editor of Boston Review and has written for WBUR, Alternet, McSweeney's, Jacobin, and others.

Guest blogger Elizabeth Manus is a writer living in New York City. She has been a book review editor at the Boston Phoenix, and a columnist for The New York Observer and Metro.

Guest blogger Sarah Laskow is a freelance writer and editor in New York City. She edits Smithsonian's SmartNews blog and has contributed to Salon, Good, The American Prospect, Bloomberg News, and other publications.

Guest blogger Joshua Glenn is a Boston-based writer, publisher, and freelance semiotician. He was the original Brainiac blogger, and is currently editor of the blog HiLobrow, publisher of a series of Radium Age science fiction novels, and co-author/co-editor of several books, including the story collection "Significant Objects" and the kids' field guide to life "Unbored."

Guest blogger Ruth Graham is a freelance journalist in New Hampshire, and a frequent Ideas contributor. She is a former features editor for the New York Sun, and has written for publications including Slate and the Wall Street Journal.

Joshua Rothman is a graduate student and Teaching Fellow in the Harvard English department, and an Instructor in Public Policy at the Harvard Kennedy School of Government. He teaches novels and political writing.


Browse this blog

by category