When you have a tiny little flower waiting to be photographed, why do you want to ignore it and concentrate on the tinier droplets of water on stalks in front of it? As George Mallory is famous for saying, “Because it is there.” One of my last trips with a Panasonic of many years, was to Kaas Plateau, that unique and very difficult habitat which contains some species of wildflowers not found anywhere else. I’d scratched the lens when I fell off a slippery boulder, and spent a year thinking I would replace it. Also, sensors had become better, and data buses faster, so it made sense to replace the camera.
I dug up this image because in the last few days I’ve been obsessed with figuring out how to do at least a half-way decent job with black and white photos. It is something to worry about, but I’m getting there. The plateau bursts into flower for a couple of weeks towards the end of the monsoon. I’ve never been there when the sun is out. You see marvelous (but tiny) flowers, but you are always wet. It is a job keeping your equipment dry. Doing it in a mask is one thing that I do not want to try.
Kaas plateau is a seven hour drive from Mumbai. The herbs flower in the closing weeks of the monsoon: between September and early October. Many of the flowers you see here are also found in the nearby Mahabaleshwar plateau and in Lonavala, closer to Mumbai. Expect lots of small herbs, few bushes and trees only rarely. Be prepared for long walks in rain and mud, with no food and water except what you carry with you.
Flowers and herbs of the Western Ghats, especially of the Sahyadris, are now well documented. There are many guides for amateur naturalists like me. I was introduced to the pleasures of flowers by Adesh Shivkar and Mandar Khadilkar; google them if you wish. There is nothing available yet for an amateur explorer of the fascinating tiny world of mosses and lichens (see the featured photo).
The bladderwort (called Utricularia by botanists) is the biggest family of carnivorous plants. In the Kaas plateau we saw large fields of purple bladderwort. The plant is aquatic: it floats on the thin film of water trapped above the stone of the plateau. The long stalks of the plants grow leaves at intervals. The bladders, which give the family its name, grow along the leaves and usually stay below the surface of water. Bladderworts are widely known to be carnivorous plants. Their bladders trap tiny invertebrates. I later found that this two hundred year old picture of carnivory may be wrong.
Plants turn to carnivory when the soil is poor in nutrients. However, they do not give up photosynthesis; their leaves are still green with chlorophyll. Carnivory gives the plant nutrients like phosphorus and nitrogen which are in short supply in the soil. The first blow to the idea of purple bladderwort being carnivorous came from careful measurements of the animals found in the bladders. These showed that at most 1% of the nitrogen and phosphorus that the plants need can come from the animals.
Yet more amazing is that each of the bladders seemed to contain a whole live ecosystem of the small invertebrates which were trapped. New bladders did not have them, and older bladders had more animals. So it seems that the purple bladderwort is not a carnivore. It must gain something else by sustaining this ecosystem inside itself. Unfortunately no one knows yet what the plant gains from this. But it seems that the purple bladderwort (named for the purple flowers you see in these photos) may not be a carnivore.
The purple blue flowers of topli karvi (Strobilanthes sessilis) blanketed the plateaus of Kaas and Chilkewadi in September and October of 2015 and 2016. A photo I had taken in the windmill-infested plateau of Chilkewadi last year shows the flowering bushes. Last year the weekend I spent in these high plateaus near Satara was rained out; we did not see the sun at all. This year the threatening skies remained dry, but the topli karvi was not in bloom. It blooms every eight years. The next blooming is expected in 2023. Botanists give the name “mast seeding” to synchronous flowering of many plants of the same species after intervals of several years. The Western Ghats have several species of Strobilanthes which do mast seeding.
You can see one of the round bushes of topli karvi in the foreground of the photo above. I looked closely at it. It was healthy, free of parasites and seemed to be vigorous. As far as I know, these bushes do not die after a flowering, unlike bamboo, which dies out after a mass flowering. Botanists would call the bamboo monocarpic, and the topli karvi polycarpic. Around these bushes you can see other flowers. This patch was full of flowering shoots of the common balsam (Impatiens balsamica). I’ve seen other flowering shoots poking out of the karvi bushes. But it is easy to pick them out. The topli karvi is a low round bush with dark green hairy leaves with serrated edges (see the featured photo for a closer look at the leaves).
I’ve never seen the fruit of the topli karvi, although I was told that it remains on the bush for most of a year. I’m not sure whether this information is correct. This behaviour is attributed to a different species of mast seeding Strobilanthes in a Wikipedia article: the hill karvi or the Strobilanthes callosus. I’d also seen the hill karvi flowering last year, and did not see it this year.
Two years ago The Family had taken the photo of flowers of topli karvi which you can see above. I saw a few scattered bushes in flower this year. The featured photo shows a flower bud developing. If you really want to see karvi flowers, it seems quite possible that you should be able to do this every year. It is mast flowering that you must wait for.
Why did Strobilanthes take to mast seeding, whereas other plants in the same plateaus flower each and every year? Some people say it is because of variable rainfall and heat; some years are just not conducive to flowering. Maybe so, but then other nearby plants flower every year. Some say that these plants could be responding to the weather quickly by flowering, but then the eight-year cycle would not hold, because the monsoon does not have such a predictable cycle. A third set of people say that the karvi has this long cycle because it is synchronized to the long cycle of a pollinator. I haven’t seen a study of the pollinators of the karvi, and in any case this just shifts the problem on to another species. Why would the pollinating species have a long cycle? Since I have not seen the fruit of karvi, I do not know whether this has such large seeds that it is inefficient for the plant to seed every year. Could it be, as some believe, that synchronized seeding serves to produce such a large amount of fruit or seed that animals which eat these cannot possibly eat all the fruits or seeds produced in a mast seeding year? I guess someone has to study the animals which feed on karvi to find out.
Although the topli karvi grows widely, it is a mysterious plant. This is a mystery which I will not be able to solve. The solution will come from a younger person who can see it go through several cycles of bloom and fruit.
The carnivorous sundew which you see in the featured photo is properly called the Drosera burmanii or Burman’s sundew. It is mistakenly called Burmese sundew sometimes. The story behind the name took me back to the origins of modern biology. It was described in detail in a book by the Dutch physician Johannes Burman, who spent a few years in Sri Lanka. His assistant in the production of this book, called Thesaurus Zeylanicus, was Carl Linnaeus. This was 1735, and Linnaeus had just published his own book, the Systema Naturae, which was to change the world by inventing a new way of naming all living creatures. Linnaeus’ naming system is the one all biologists and amateur naturalists follow. Darwin, in his book Insectivoruous Plants, remarked on the common trapping mechanism through the sticky “dew” which you can see in the photo, and classified all sundews into one family, which is still called the Droceraceae.
Darwin was a wonderful naturalist and asked most of the questions which keep drocerologists busy till today. Are the sundews selective about their prey? In the nearly three centuries that have passed since the first descriptions of sundews, all evidence indicates that they are generalized carnivores. They feed on whatever gets stuck in their dewy glue. How large can their prey be? Darwin believed that they feed on fairly small animals. Strangely, there have been no measurements of their prey since 1925; and that was the first one since Darwin himself. So, if you happen to take photos of any sundew with its prey, you will add substantially to the sum total of human knowledge. I scanned about 20 plants quickly, and if they had captured prey, then they were too small for me to see with my unaided eye (the photo here shows a small insect stuck to the plant). Are all carnivorous plants related? Fossils and genetic data seem to say that carnivorous plants evolved six times independently from completely different origins; so the bladderworts and sundews that I saw were not related.
A question that Darwin never asked is why a plant would turn from photosynthesis to carnivory. The general observation that these plants grow in nutrient-poor soil was taken as enough of an answer. However, there are other entirely photosynthetic plants which grow all around the sundew, so this is not a complete answer. Studies show that carnivorous plants grow and spread better once they get enough prey. Notice the bits of green on the leaves of the D. burmanii? These contain the usual chlorophyll that allow plants to use sunlight to make sugar. The density of spiny hairs is much smaller on this portion than in the red part of the leaves. So they also do photosynthesis, but they are less efficient at it. The complete story of carnivory versus photosynthesis is not yet known.
In the same patch of ground where I took the other photos, I also saw several flowering specimens of Drosera indica (one example in the photo above). This was first named by Linnaeus in 1753 based on a drawing of a plant collected in Sri Lanka. A field study in 2013 by Allen Lawrie found that there are actually 11 different species which were conflated into the single species D. indica. Are there several unrecognized species hiding behind this one label in India? I do not know the answer.
While we talk about names, you will notice that I have called these plants carnivorous instead of following Darwin and calling them insectivorous. This is because detailed counts of prey species indicate that sundews feed on anything the right size, without specializing in insects. I’ll not say much more about D. indica because I’ve already written about it in another post.
Are D. burmanii and D. indica in competition when they grow in the same patch of ground? Studies of prey captured by other carnivorous plants which grow together show that they capture the same species, and so may be considered as competing. I know of no studies of prey species among the sundews of the Sahyadris, but there is no reason to believe that they are exceptions. In that case the spreading stalks of the indica with their larger numbers of leaves possibly give it a photosynthetic edge. Maybe that is why they are more common. I wish I knew a professional ecologist who could answer these questions.
“What’s that flower?” The Family asked me as I was stalking a Ceropegia. I looked around at the pentagonal white shapes on a stalk that was about 20 centimeters high. “I don’t know”, I said, as I took a photo for later reference. She soon found that it was not a flower. A flower has sexual organs, and this did not have any. Mandar explained that it was the opened fruit of the Dipcadi montanum. I’d posted about this plant from the Hyacinth family last year after a single sighting.
This year I’d seen it several times. In fact just a few minutes before I’d seen another stalk which had started fruiting. You can see the fruit towards of the bottom of the stalk in the photo here: a dark green knob. The chance sighting I had last year was of the D. montanum plant standing in a field of bladderwort (Utricularia). Each sighting this year showed the same thing. In fact, the purple spots which you see in the featured photo are purple bladderwort. The linkage between the two just got stronger in my mind because of this statistical improvement. Typically the bladderwort grows in poor soil, and gets nourishment from digesting small insects. There is evidence of a rich ecosystem which grows inside the bladder. Does this ecosystem produce benefits to the thin soil around it which are reaped by the bulbs of the Dipcadi? I don’t see anything written about it.
I got a sharp photo (above) of a flowering Dipcadi on the nearby lateritic plateau of Chilkewadi. The spots of white that you see in the photo are of globular pipewort (Eriocaulon sedgewickii). These are known to grow in association with bladderwort. In fact the field had some, although they do not appear in the photo. The triple association of Dipcadi, bladderwort and pipewort is very strong, and cries out for an explanation.
The genus of plants called Ceropegia are pollinated in a very strange way, The Family explained to me. After her first trip to Kaas plateau two years ago, she showed me photos of this strange flower and explained how they trap flies to pollinate themselves. The upright flower opens up and flies come in to look for nectar. As soon as they land, the petals close into the cage shape you see in the featured photo. The frantic fly buzzes about and pollinates the flower. After this the flower droops down and opens up to let the insect out. In the bunch of Ceropegia vincaefolia that you see in the featured photo, two of the flowers are ready, and the droopy one has been pollinated already. These tall bushes were fairly common around the Kaas lake. Apart from the mode of pollination, I found the green colour of the petals rather unusual.
But the most marvelous sight of the trip was this tiny plant on the plateau: Ceropegia jainii. I was lucky to be with two naturalists who knew roughly where to look. This species is a little rarer than tigers. In the photo you see the green egg-shaped base called the crown kettle, and the purple crown tube formed by the five petals. If you look closely, you will see the downward pointing hairs inside the tube which trap the fly. If this flower is similar to that of the C. vincaefolia, then at the narrow bottom of the crown kettle is the hard-to-reach corolla. I was not going to dissect such a rare flower to look inside it. The whole flower is a little less than two centimeters long. You can see that it grows on an unbranched stalk with thick leaves. In the photo above you can see other buds forming on the stalk.
I was so thrilled with the sight that I noticed the caterpillar only after looking at the photo. It will eventually grow into the spectacularly coloured butterfly called the plain tiger (Danaus chrysippus). I don’t know whether there is an association between this and C. jainii. Since host plants of the plain tiger include other known milkweeds (family Asclepiadoideae) it is not impossible. On the other hand, I did not see the typical circular holes that the caterpillar makes in the leaves of its host plant. In any case, this is something to watch for in future.
The region of the Western ghats around Satara and Pune are full of large plateaus and oddly shaped peaks. When you travel through them, the first impression you have of the mountains is that they look like a layered cake. I stood at the Thosegarh waterfall (featured photo) and found that even the monsoon-fed vegetation could not hide this appearance. The layers are a succession of lava flows, laid down in a massive burst of volcanism 60 to 100 million years ago. These successive layers of lava are called the Deccan traps. I found it hard to estimate the thickness of the layers by eye, but going by the heights of trees, perhaps they are between 50 and 100 feet thick. Since each layer of lava covers a considerable area, this means that each burst of volcanism would have lasted long and spewed out immense amounts of rock and ash. Not only would this have killed all life where it flowed, it would have dimmed the sunlight reaching the earth, and contributed to a mass dying of vegetation around the world.
In the 60 million years since it contributed to killing off dinosaurs, the traps have weathered. Today we see them as flat topped hills, cut through by deeply eroded valleys. Some of the waterfalls lead down to rapids extremely suitable for white water rafting. In other places there are very wide valleys. The town of Satara, which you see in the photo above, lies in the extreme western end of the rain-shadowed region of the Deccan. As a result it gets sporadic monsoon rains, enough to keep it green. The urban sprawl gets its drinking water from the river Umboli, which arises in the Kaas plateau, about 25 kilometers away. Traveling in this area, I saw many high plateaus. At one point each of them must have been home to the variety of flowering herbs and bushes whose diversity is now mainly visible in Kaas.
When you reach the top of one of these plateaus you see exposed rock everywhere. This is the volcanic rock called laterite, formed by weathering of the traps. You can see the dark porous rock peeping out from the low cover in the photo of the Kaas plateau above. There is hardly any soil. What little there is forms in little depressions in the rock. This area is covered by tiny herbs: mainly the carnivorous bladderwort (Utricularia) and sundew (Drosera) species, and tiny coexisting herbs. Between such rocky outcrops, there are deeper fissures where a little more soil can collect. There are higher bushes such as the Topli Karvi and arrowroot. There are very few trees on the plateau. What little soil forms is constantly removed by rain and wind. It is a marginal environment where extremely specialized plants grow. Twenty meters below the top, soil can accumulate, and the vegetation changes quite dramatically. It becomes characteristic of the rest of the Sahyadris. As a result, these high plateaus are like islands: the flora of each plateau is isolated from those of its neighbours.
When you walk through the Kaas plateau your eyes take in the evidence that geology determines ecology, that life is shaped by the land.
I’ve written about the world heritage Kaas plateau before. I went back there over the weekend. The volcanic rock barely holds any soil, and what little is there has little nutrient. The plants that one can see here have evolved in this hard environment. As a result, this 10 square kilometer area at an altitude of about 1.2 kilometers is an island mountain: the flora here is isolated from flora in other plateaus in the region. There’s a brief but glorious flowering at the end of the monsoon. By all accounts the flowers change almost every week.
The most famous plant here is the Topli Karvi (Strobilanthes sessilis) which blooms in mass once every seven years. Last year this was in bloom. This year the general view (see photo above) did not show any of the bright blue flowers of this bush. One had to search hard for the few isolated and idiosyncratic bushes of S. sessilis which flowered this year. Instead the landscape was full of patches of white globular pipewort (Eriocaulon sedgewickii) mixed in with the vivid colours of the carnivorous purple bladderwort (Utricularia purpurascens). In other places we patches of the yellow sonkadi (Pentanema indicum) mixed in with the violet rosemary balsam (Impatients oppositifolia). You can see all four species in the featured photo.
This week the balsam outnumbered everything. Most green patches had highlights of violet. Maybe by next week the sonkadi will dominate.
Since this post is about creatures fairly high up on the food chain of the Kaas plateau, I could start with the top predator I saw: the funnel-weaving spider (family Agelindae) you see in the featured photo. This one had laid down a huge sheet of a web covering several Topli Karvi bushes, and was waiting for food to fall out of the sky. When an insect lands on the web, it usually runs very fast to it and engulfs it in silk. Now, with rain drops falling intermittently on the web, I’m sure this guy had his work cut out, trying to distinguish rain from food. Other insectivores on the plateau are plants: sundews and bladderworts. I’ve written about them elsewhere.
This snail is about the largest animal I took a photo of on the plateau. There are birds; the Crested Lark (Galerida crestata) had put in a hazy appearance in the morning mist. After it started raining we saw no birds. The rain does not stop a snail, as it munches the roots of Topli Karvi bushes. This was on its way from one bush to another, when I saw it. It didn’t seem to move as I took the photo, meaning it would take an age and half to get to the next busg. The western ghats harbour a large variety of land snails; I’m not sure which species this is. Any expert comments?
One of the more common animals which inhabit these parts are grasshoppers. Judging by where it was sitting, this one probably feeds on the leaves of Topli Karvi. It has a silly startled look, as it turns its head slightly to take a look at the relatively large camera lens looking at it. I couldn’t get a shot of the three eyes it has on top of its head. Again, I have no idea what species this is, and have to depend on the kindness of an expert to provide the answer.
A very strange animal was this leaf piercer. It stood on this leaf for a long while as people tried to photograph it. The early photos show a little spot of sap on its long snout. By the time the last photos had been taken the sap had disappeared: it had done its version of licking its chops. I have no further idea about the classification of this beautiful and strange beast.
Interestingly, none of these animals are pollinators. This tiny moth which flew on to a Topli Karvi leaf while I watched is also unlikely to be a pollinator. It is quite likely to be another herbivore. Interestingly, the leaf it is sitting on already has been attacked. Usually true bugs (order Hemipteran) attack plants in this way. Unfortunately I didn’t see any.
I didn’t see a single butterfly in my few hours in the Kaas plateau. It was raining, and butterflies don’t like to get their wings wet. More likely, the butterflies had not pupated yet. I had evidence for this soon afterwards when we arrived at a grassy meadow full of caterpillars. I don’t know which butterfly they will metamorphose into, but the complete fearlessness with which they crawled across the ground, and the absence of predators, probably means that they are toxic.
I’m sure I missed a very large number of insects. It was raining hard, so most of them were probably hidden under leaves. Since it was muddy, I was not intent of kneeling or sitting to peer under the low leaves of the Karvi. So I’ll have to leave the job of talking about more beasts of the plateau to someone else.