Invasion

Mass murders can happen in front of your eyes without you looking away. Some things are just so hypnotic. Lantana camara was taken by humans and planted in gardens across the world. As a result, this species from the tropical Americas now infests the old world, from China in the north to New Zealand in the south, from Spain in the west to Fiji in the east. The flowers are cheerful clusters of brightness, but it is a beautiful face which hides a murderous heart.

It is a noxious plant. It harbours toxins which are released in the gut and are strong enough to kill small animals. This is bad enough for farmers, and has induced them to spend effort in clearing Lantana from their land. But it is worse in forests, where it can grow unchecked and kill small wildlife. A study found that it can cause great changes in bird communities in forests. It is specially damaging in the bioreserves and protected forests of India because these are places where human intervention should be kept at a minimum, but control of Lantana sometimes calls for large-scale intervention.

It also spreads rapidly, both by seeding and vegetative expansion. It co-opts many local species of butterflies and moths by producing a large volume of nectar and luring them into providing sexual services. That’s why each flower is shaped like a long, narrow trumpet. This fills up quickly in rain, as you can see in these monsoon season shots. When I want to take photos of butterflies, I look for Lantana patches which are partly sunny. But the nectar also attracts robbers which do not serve to pollinate. These include some types of bees and also nectar feeding birds. The birds have learnt to pluck the flowers and suck the nectar out from the wrong end.

But the plant does not seem to care too much about this loss. It has highly evolved sexual strategies. For example, its flowers change colour after they are fertilized, so that pollinators are attracted to the unfertilized flowers. That’s why every bunch of flowers is multicoloured. Also, in each bunch, the outer flowers open first, the inner later, to reduce self-pollination and thereby increase the chances of vigorous offspring. Moreover, it hybridizes readily, which is why you see such a variety of colours in the wild. This ability, and the consequent ease of generating different cutivars is what attracted gardeners in the first place.

Dove or pigeon?

A typical question that I get asked when a stranger finds out that I’m a birdwatcher is, “What is the difference between a dove and a pigeon?” I’ll usually give a facile answer, “They are closely related. Doves are generally smaller.” But the difference is actually more complicated. Take the spotted dove (now called the Spilopelia chinensis). Its name reflects the confusion. It was once thought to have been a dove, and was given the Latin binomial Streptopelia chinensis. Following a multi-species gene study at the beginning of this century, it is now thought to be a small pigeon. It has been placed in a different genus accordingly.

It is such an utterly common bird that I normally ignore it, but just before sunrise inside Tadoba’s buffer zone, the bird strutted in such a wonderful rosy light, that I clicked the two photos you see here. How common is it? I can see records of it being spotted (yes, I will avoid the bad pun) all across Asia, south of Mongolia and east of Aghanistan, except in Tibet and Xinjiang in China, Japan, and Korea. Since the 19th century it has been reported southwards everywhere in Australia from where it spread to New Zealand, into Fiji, and Hawaii.

It has now been reported across the Pacific in California, from as far north as Sacramento, and as far south as San Diego. Why has it not crossed state lines? Could that be because it is a recent arrival in the US? A little search led me to a claim by Audubon that they were introduced in 1917. I’m not sure whether I believe that date. They breed fast, fly well, and manage to avoid raptors in their native range. So in a hundred years I would have thought it would spread further. There’s a small mystery here.

Flower for Friday

My new camera gave me a really close look at this tiny flower. The flower is less than two millimeter long, and the whole cluster that you see above is certainly less than a centimeter across. I was very happy to find that the camera can catch such tiny details. That lovely macro lens and the waterproof body makes it an ideal compact to take with me on monsoon walks. The flower is unusual; I haven’t seen many green flowers.

Focus stacking is an immense help in the field. You take one photo, and your camera catches lots of things around it in beautiful focus. I was fixated on the featured photo, but the camera also gave me part of the surroundings. The stalk and the placement of the flower, the shapes of leaves, everything helps to identify it. It is very likely to be the sessile joyweed (Alternanthera sessilis). Although its present range seems to include most of the world, it is said to originate in the West Indies. So I don’t know who gave it the Sanskrit name Mastyakshi, which means fish-eyed. It was definitely a late naming, because by then the different Indian languages had evolved many different names for the plant. I’m surprised to find that it is edible, and it is even sold in markets in Sri Lanka!

Invader!

New tools need to be tested. I’m not yet familiar with my new camera. So, in Vaitarna I was still playing with focus stacking when I aimed it at patches of growth. The results surprised me over and over again. Once it was these tiny white flowers, each about a millimeter in size. They grew in clusters, and each cluster was less than a centimeter across. If I’d looked more carefully, I would have also tried out a further zoom. As it is, I have to be satisfied with the photos you see here. It took me a while to identify this as the Alternathera tenella.

Why does it not have a local name? Simply because it is an invader. This diverse genus, containing 80 to 100 species, is largely confined to the tropical Americas. In fact, recent genetic studies seem to trace this species to the Galapagos. It is used in Brazilian folk medicine, and has generated a huge literature. The fact that it is not used in local folk medication shows that it is a rather recent arrival. Several species of Alternanthera are persistent weeds, as this one must be (specimens have been collected in Odisha earlier). What are its pollinators? Is each flower perfect? I don’t know. But I’m happy to have a camera which lets me into its tiny world.