Waiting for Strobilanthes

I wouldn't be surprised if this turned out to be the Hill conehead (Strobilanthes reticulata)

There are about 350 species of Strobilanthes, and some of them flower only once in several years. Last year I had gone to a plateau near Satara to see the Strobilantes sessilis in bloom; this happens once every seven years. During monsoon this year the Strobilanthes kunthiana will bloom for the first time since 2006. I reached Erivakulam national park just a few months too early for this. I was determined to take photos, so I took a photo of the bush. I’m not going to be mistaken about the flower when I go back in September.

The protected area of Erivakulam is a tiny sliver of land between tea estates, but it has an astonishing variety of Strobilanthes, called Kurinji in Kerala and Tamil Nadu. I photographed several types, and you can see them in the gallery above. Unlike their famous cousins, these flower every year.

The Karvi does not bloom any more

Windmills in the middle of fields

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.

Topli karvi bushes in Chilkewadi

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.

Topli karvi flowering in 2015

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.

Plateau of flowers

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.

Kaas plateau: landscape

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.

The eight year itch

I can’t believe that I wrote a piece saying goodbye to the monsoon on Saturday. On Sunday I was at the Kaas plateau. It rained all morning. The thin layer of soil was saturated with rain. Then other Sunday visitors turned up, and the soil on the road turned to a well-churned slush. The official website says that 3000 people are allowed each day. It seemed to me that there were many more people there on Sunday. People waiting to get into the fenced-off part of the plateau lost their patience. Someone lost their spectacles. I found the featured image.

Karvi in bloom on Kaas plateau

The press has been full of reports about the Topli Karvi (Strobilanthes sessilis) blooming this year after a gap of eight years. We found fields full of flowering Topli Karvi (see the photo alongside). But then there were large patches of these knee-high bushes which did not have any flowers. The Family had visited the plateau last year and come back with photos of Topli Karvi flowering in some patches.

Seeing her photos, I’d speculated that Topli Karvi could bloom once in eight years, but different patches could bloom in different years. Then this would not be a textbook case of mast seeding, such as that seen in the related Strobilanthes Kunthiana (Neelakurinji, which is supposed to flower next in 2018), in which the plants die after flowering. Incomplete synchronization of the flowering of some species of Strobilanthes has been reported from Japan, so this is not a radical idea. It would be nice to see data on this species.

View of a path on the Kaas plateau

I did not see any of the usual pollinators. Perhaps it was raining too hard. The previous evening, near the Thosegarh waterfalls I’d seen Indian honeybees in a stand of the related Strobilanthes callosus (Karvi). Dhamorikar has a very interesting observation about the Karvi: it is pollinated by bees, flies, ants, some moths and maybe even the Oriental White-eye. He speculates that the purple colour of the Karvi has evolved to attract a large number of pollinators.

There aren’t that many flowering cycles of Karvi in a lifetime. More than one life may be required to solve the mysteries of the blooming of the Karvi.