Leaves That Look Like Abstract Maps

Leaf detailPhoto:
Image: Jeff Kubina

What would the world be without a bit of imagination? Maybe more straightforward but certainly less magical. That’s why we’re going to take a near microscopic tour of leaves, that’s right, ordinary green, yellow, red, orange and even purple leaves. We were wondering what they must look like to those crawling on them and, after putting ourselves in the insects’ shoes, made a stunning discovery: they live like us! They have networks of highways, streets, rivers and some very orderly settlements. The leaves seem to document these and work as their maps! Very interesting indeed…

Here’s an example of urban density:
Autumn leafPhoto:
Image: Fred Jacobs

And another one – that’s Toronto:
Toronto city mapPhoto:
Image via ccablog

Orderly settlements:
Green leafPhoto:
Image: Jan Krömer

Follow the main road, take the second left and the third right. We’re the fifth settlement on the left:
Simple brown leafPhoto:
Image: Rawhead Rex

Leaf veins are the intricate and fascinating structural skeletons of leaves. They are also essential systems of nutrient and water transportation. Each vein consists of water-conducting tissue called xylem and sap-conducting tissue called phloem. They are surrounded by a protective wrapper of structural tissues. The space between the veins – a tissue called parenchyma – is packed with chloroplasts, the organelles responsible for photosynthesis.

The arrangement of the veins on a leaf is called venation. Here’s a good example of a leaf with pinnate venation, meaning one mid-vein with smaller ones branching off laterally.

Always stay on the main road!
Leaf of a Mexican plantPhoto:
Image: Alex

A leathery map:
Orange-brown leafPhoto:
Image: Steve Jurvetson

Agricultural fields or skunk cabbage leaf?
Skunk cabbage leafPhoto:
Image: The Montessorian Librarian

Green indicates the suburbs, red urbanisation:
Like a cauliflower leafPhoto:
Image: Peter Shanks

Hey, Havana is a leaf!
City map of HavanaPhoto:
Image via cubamapa

Zoning is in effect in Poinsettia:
Euphorbia pulcherrimaPhoto:
Image: Kevin Dooley

Researchers have been fascinated by the patterns that leaf veins form and discovered that only one simple mechanical model may be at work in all leaves. Comparing leaf vein networks with webs of ropes and threads, in the model below, the spot where a small vein joins a large one is marked with a green arrow. The angles between the smaller and larger vein approach 90 degrees, like the angles would be when pulling on a light thread tied to a taut rope. Tree-way junctions of veins of the same size are marked with a red arrow and the angles between them have been found to be roughly 120 degrees.

Here’s the rope web model:
Like a rope networkPhoto:
Image via aip

And here a leaf in black-and-white, quite sinister looking urban planning:
Black and white image of leaf structurePhoto:
Image: worak

There are two subtypes of venation distinguished by the extension of the veins. Craspedodromous venation describes those leaves where the major veins stretch up to the margin. In camptodromous leaves, major veins extend close to the margin but bend before they intersect with it. Below is an example of a craspedodromous leaf.

We live in Victoria Amazonica – take a right where the second main road forks:
Victoria amazonicaPhoto:
Image: Frank Wouters

Here’s an example of a camptodromous leaf.

Strangely looking like a slice of pepperoni and jalapeno pizza:
False Holly Osmanthus heterophyllusPhoto:
Image: Derek Ramsey

Just as with human cities, insect settlements have their preferred areas.

The lake properties off the main road are very sought after:
Yellow leaf with strong red veinsPhoto:
Image: a.pitch

Properties on the purple hills are quite upmarket:
Purple leafPhoto:
Image: Matthew Venn

Urban planning nightmare:
Leaf detailPhoto:
Image: Steve Jurvetson

In leaves, the main thoroughfares are called veins and in cities traffic arteries – something to ponder.

Right off the highway is our purple bougainvilla…
Purple bougainvillaPhoto:
Image: g_kat26

Flaming red landscape:
Autumn leaf in red and yellowPhoto:
Image: Jannes Pockele

Wintery landscapes have also been captured.

A snowy landscape with green patches:
Green and white leafPhoto:
Image: Lawrie Cate

The orderly settlement in winter:
Leaf in black-and-whitePhoto:
Image: Mark Boucher

White road map or elephant ear?
Caladium leafPhoto:
Image: Peggy Swientek

Who said there are no alien insect life forms out there?

Green Insect Earth as seen from space:
Leaf with mites through microscopePhoto:
Image: Cod Gabriel

A Martian landscape:
Red leafPhoto:
Image: Victor Sounds

The alien invader says good-bye!
Bug on a leafPhoto:
Image: Jenny Downing

Sources: 1, 2, 3