We are surrounded by a diversity of plants ranging from trees to mosses. There is not only diversity in plant species but also plant parts. For example, the flowers of different species look very different. There is also a lot of variation in leaf shapes, flower petals, flower colours, seeds, and tree barks. However, what we often overlook is the variation in leaf colours and shapes. The beautiful colours that we see on fallen leaves have fascinated me for the past few years. I have been trying to capture this diversity in leaves’ shapes, colours and sizes through my art, to draw attention to the world of plants. This journey has been exciting, as these detailed observations of leaves have given me insights into plant identification, seasonal changes in plant biology, and even plant enemies. Every leaf has a story to tell.
I started making life-size leaf paintings five years ago. It began as an activity to pass time in the evenings, while doing fieldwork; I did my fieldwork in the forests of the Western Ghats, at the border of Karnataka, Maharashtra and Goa. These forests are rich in plant diversity, and that meant I had a new leaf to paint every day, and a different pattern to observe every time I sat down to paint.
Usually, leaves are green or have shades of green. We all know that the green colour in leaves is because of chlorophyll. Chlorophyll is a green-coloured pigment and is used by plants to make food. Similarly, other pigments in plants, such as carotenoids and anthocyanins, give fruits, leaves, and flowers their yellowish, reddish, or orangish tinges. When leaves become old, their chlorophyll content drops and hence the green colour disappears, but the proportion of carotenoids increases, and thus we see leaves turning yellow. The interesting part is that before shedding its leaves, the plant absorbs the chlorophyll from the leaves and uses the energy trapped in the chlorophyll molecules. Hence, the green colour disappears and only the carotenoids remain, giving leaves their yellow colour.
When the proportion of anthocyanins is higher, the leaf becomes reddish-orange in colour. Many plants in temperate regions – like maple and oak trees – show vibrant hues of red, orange, and purple. In tropical countries such as ours, this phenomenon of leaves becoming red is rare. However, there are exceptions, such as Terminalia catappa, Terminalia arjuna and some ficus species; the leaves of these trees turn completely red and orange just before the trees shed leaves in the post-monsoon months.
While painting these fallen leaves, I observed that some leaves show vibrant colours ranging from bright yellow to red or even purple, but some turn black after they wilt. I had not encountered leaves turning black very often, and I wondered what gives leaves their black colour. I did some preliminary observations and found a fascinating explanation for this phenomenon. I observed that if a green leaf falls off a tree because of strong winds or some animal plucking it off and throwing it down, it turns black. Such green leaves don’t become yellow or orange because the tree hasn’t absorbed the chlorophyll from the leaves (since the shedding wasn’t scheduled), and this chlorophyll then darkens and turns the leaf dark as it wilts.
Observing these colours is one part, but watching the patterns on leaves gives other insights, such as fungal attack and herbivory. Sometimes, I have seen that leaves that are completely dry show specks of green. Initially, when I would find such leaves and begin painting them, I thought the leaf had not dried completely, and therefore, there was some remnant green color. I then observed that even after the leaf completely dried, these spots were still green. If one pays attention to these specks of green, they look like some fungal attack. I think these are fungal colonies growing on the leaves and hence have a different colour from the leaf. Examining these spots under a microscope might give us the answers.
There are even stranger patterns often seen on leaves – black spots that look like drops of tar, shiny and hard in texture; rusty brown spots that appear powdery on a closer look; or bright green circles that appear like algae. There is more to these patterns than we know and a lot more remains to be discovered.
Let’s take a closer look at the plants around us – the leaves of most plants appear to be damaged. All kinds of herbivores attack plants and feed on them, leaving pieces of evidence that the plant is being attacked. For example, holes in leaves, edges of leaves that are chewed upon, a netted pattern where only the veins remain but the lamina of the leaf is all eaten up, or sometimes two leaves stitched together. Grasshoppers and crickets start eating a leaf from the edges, while caterpillars often bore holes in the center of the leaf, and sometimes, caterpillars of some moth species stitch leaves together to form a protective covering and then eat the leaf from inside. Thus, looking at the damage, one can guess what must have attacked the plant. The leaves that survive these attacks are permanently scarred.
Painting these leaves has given me a chance to be with plants and discover the many secrets hiding behind leaves. This process has taught me about natural history, plant-herbivore interactions, plant biology, and many more exciting things. The goal behind painting these leaves is two-fold for me – one is to highlight plant diversity, and the second is about discovering secrets about the plant world through art and scientific inquiry. My quest for finding different leaves, unusual patterns made by herbivores on leaves, and vibrant colours continues. I hope everyone finds enough inspiration and intriguing stories to tell about plants and leaves on your jungle expeditions, or even from your backyard.