Chasing prickly poppy

Driving back after our last safari, I stopped the car where a patch of kateli (Argemone mexicana) was in flower. I use the common Hindi name for it, although it is not an Indian plant. A less popular name, vilayati datura, is actually more explanatory. It says that the plant is exotic, and also indicates that it is poisonous in some way. Livestock avoid it, perhaps largely because of the thorns. But it can kill if they eat enough of it.

The Encyclopedia of Food Safety sent shivers down my spine with the warning that its oil contains “the toxic quaternary benzophenanthridine alkaloids sanguinarine (approximately 90%) and dehydrosanguinarine (approximately 5%) with lesser quantities of cheletrythrine and coptisine, and small quantities of berberine and protopine, which are isoquinoline alkaloids.” I didn’t understand a word of this, but it sounded menacing. Before cooking oil became available in tamper-proof packaging, there were some incidents of cooking oils adulterated with kateli oil. As you might expect, this resulted in deaths. All plants in the poppy family (Papaveraceae), to which it belongs, harbour toxins.

I’ve grown up seeing this plant in the kinds of degraded land which a city kid finds fascinating: the sides of roads, abandoned half-built houses, even in the cracked concrete of parking lots. Mumbai doesn’t have much; perhaps it is too wet. But across most of the dry Indian planes, even as high up as the lower valleys in Bhutan, the prickly green leaves spread a carpet over wasteland, a carpet which sprouts showy yellow flowers through autumn and winter. Now, with the right tool I could look closely at the flower. Some would hesitate to say it is beautiful, since it has six petals, and six is not a Fibonacci number. But I’m not one of them.

Knowing that it was exotic sent me on an interesting chase. It seems to be found across the tropics; it can be found across south and south-east Asia. I followed its recent progress across Africa: from Kenya to Angola across the continent and up and down the coast. It has been spreading across southern Europe and the Mediterranean basin recently. The genus Argemone contains 24 species, not all of which are equally invasive. The center of diversity seems to be in south-western US, but it is spread across central and south America, including the Andean region. A single species has been found in Hawaii. A study made in the Ngorongo bio-reserve found that seeds traveled hidden in construction material, and then were dispersed in the tyres of vehicles. Perhaps that’s how the invasion of the prickly poppy started.

White bark acacia

The forest department is meant to conserve ecology. Unfortunately, they interpret their job to mean they are supposed to grow forests. As a result, they are changing the desert scrub ecology of the Rann of Kutch by planting white bark acacia (Vachellia leucophloea). These plants have nitrogen fixing nodules in their roots, which are useful when you want to green a desert. That may be part of the reason why the forest department likes it. This acacia also grows naturally in other parts of the Thar desert. So, maybe, this experiment is not as bad as the one carried out in the 1970s, when the desert was seeded by the exotic mesquite Prosopsis juliflora. But the Rann of Kutch is a special habitat, and reduing the space for its distinctive flora and fauna creates a sudden change in ecology which will have effects that we cannot predict. But then, maybe none of this matters. Maybe the rising seas will reclaim the Rann very soon.

On our last evening’s attempt to spot birds in the Rann, I found myself quite distracted by the greenery. We walked gingerly between the trees, but there was little to see. You see a typical stand of white bark acacias here: spindly trunks with white bark spreading out a little above your head. The older bark turns rough and dark as the tree ages. The canopy is full of the typical feathery mimosa leaves. The flowers are very interesting, as you can see in the slideshow above. The dense round collection of white flowers are called glomerules, and they grow in a multiply branched stem called a panicle. That picture does a good job of explaining the words.

But there were too many trees, and the birds were avoiding this place. We moved away into the open land and were immediately rewarded by multiple sightings: silverbills, larks, warblers, robins, flycatchers. A single bird came and sat on a branch of a tree right at the edge of the open scrub. It was the grey-necked bunting (Emberiza buchanani) that you see in the photo above. In the setting sun and against the bright green background its drab brown plumage looks red.

Desert flowers

Aak (Calotropis procera), named rubber bush, is the typical dry area plant. You won’t find it deeper in the Thar desert, but the bushes were visible around rocks everywhere we went. In the Rann of Kutch they seem to be usually less than two meters high. Usually they attract ants, so I keep a watch on the small purple five-petalled flowers to see what kinds of ants I can spot. In Kutch, as the featured photo shows, I didn’t manage to get the flowers with any ants at all.

The succulent called Thor (Euphorbia caducifolia) is the commonest plant in this region. I spotted lots of birds sitting on a projecting stem of the bushes. You can see an Indian Robin in the photo on the left above. They can grow well above a man’s height, 3 meters often, taller sometimes. It flowers in late winter. If you want to see what the local insects are, keep a watch on its flowers at that time. They attract many of local insects wherever they grow.

Another succulent that is widely found in the desert is the Aak Thor (Cynanchum acidum). It has attractive tiny six-petalled white flowers (6 is not a Fibonacci number) which were budding from the ends of the stem; you can see them most of the year except in the winter months. It seems to be a climber. I saw stems trailing on the ground when there’s nothing else growing nearby.

The Rann of Kutch is full of many different kinds of grass or millets growing wild. I find myself completely unable to identify grasses. I’ll have to spend time learning more about this group. Many of them were in bloom at this time, immediately after the monsoon.

The low bushes of Kana (Commelina benghalensis) were very visible even from speeding cars, because of the attractive three-petalled blue flowers. There was a variant in purple which was also quite widespread. The flowers are large, petals can be half a centimeter in size. It seemed that a plant can either have blue or purple flowers, but they can grow quite close to each other. That makes me suspect that the colour is determined by genetics rather than soil.

Thorny nightshade (Solanum virginianum), Kateli in Hindi, is again a plant that is common in most dry areas in India. I’ve seen it deep inside the Thar Desert as well. Here you see the five-petalled flower poking out from under a different bush. Kateli is a spreading herb, and this particular plant was spread along the ground below this other bush. You can see it flowering around the year, except in the monsoon months.

Perhaps the commonest tree that I saw was the Khair (Senegalia catechu). It happened to be in flower. It is a typical mimosa, with the feathery leaves (called pinnate by botanists), flowers with wire-like petals, and thin gnarly trunks. They grew up to a man’s height, and spread out thorny branches which were exactly at the wrong height for me. if you add the Kair (Capparis decidua, bare caper), which I’ve written about earlier, I think I’ve listed the most widespread plants which I noticed in this area.

Bare caper

North of the great Rann of Kutch, in the center of the Thar desert, one of the daily staples for dinners are made from the branches and berries of kair. “Common names” used by amateur nature watchers are odd. In the anglophone world there is an attempt to systematize descriptive names in English, whether or not a plant or bird exists in the geography where the English commonly come across it. So the “common name” given to kair ignores the Hindi word altogether, or the Gujarati cognate kerdo, and translates the Latin binomial to get bare caper. The same plant also grows in the Arab desert and arid parts of east Africa, where, no doubt, it has other common names. I can live with using the Latin binomial as a trans-cultural name, since the system recognizes the inventors of modern systematics. So, I’ll give up on the silly name bare caper, and call the plant Capparis decidua or kair.

I’d first met the plant served up on a plate in Jodhpur, then seen it in the Rao-Jodha Desert Park in that town. After that I’ve seen it in many places in the Thar desert. But this was the first time I’d come across it in the flowering season, just after the monsoon. The plant is a climber, but when it grows alone in the desert or a clearing in a forest it looks like a bushy man-high tangle of branches. As you can see, a stalk in the bush above has adapted to circumstances by becoming thicker and growing vertically.

The capers (family Capparis) are found in Africa, Asia, Australia, and Europe, and also in north, central and south Americas. This indicates a truly ancient genesis. Molecular evidence shows an old split between the old world and new world groups of this family. The old world (including Australian) species seem to originate from Africa.

The succulent is mostly leafless. Small leaves can be seen sometimes on young branches. This time around I didn’t see any. The paired thorns are pretty well spaced on the stalks, and do not discourage human manipulation. I suppose they are still sufficient to deter browsing. The red flowers seemed to grow in bunches of three, or, rarely, in singles. I suppose they will turn into the red berries in a couple of weeks, and ripen into black in a month. Someone mentioned an achar made of the berries. We found one in a shop in Bhuj, and brought it home.

The next day I found kair vines used by farmers to make hedges around their fields. They grow dense, support other vines, deter cattle from feeding in the fields, and can be harvested for food when needed. The Sanskrit words for the plant include nishpatrika, meaning without leaves, and tamprapatraka, which could refer to the yellow colour of the leaves. But quite as interesting are alternate names like granthika and granthila. Could the reference to books mean that you can obtain a fibre from it which can be used to make paper? Extracts from the plant seem to have the potential for several pharmacological uses. What a wonderful plant!

Rao Jodha Desert Park

Ranisar lake, Mehrangarh, the blue city, and red welded tuff

We hadn’t heard of the Rao Jodha Desert Park before we looked at a map of the area around Mehrangarh. Nor, it seems, had the auto driver. We had to coax him along the well-marked road to the visitor’s center. An enthusiastic young man called Denzil then marked out a short route for us on a map of the park and explained what was special about the place.

The 700 acres within the old city wall of Jodhpur was painstakingly freed of an invasive species of plant, and local species were planted into the holes left by the deep roots of the invader. Repairs to the city walls were completed in 2005, and the process of recovering the desert ecology was started the very next year. The unlikely banker behind this army of eco-warriors was the Mehrangarh Museum Trust.

Mehrangarh, the fort which Jodhpur grew around, stands on a hill of volcanic rock made of hard rhyolite, the mineral which also forms the volcanic plugs called the mesas of Arizona. Here, they stand in flat slabs which you see everywhere. Around this is a softer rhyolitic rock called welded tuff, which is made of volcanic ash pressed together while still hot. There is a red coloured welded tuff which is commonly known as Jodhpur sandstone. Our walk took us down an ancient aqueduct quarried out of the crack which formed between a face of the welded tuff and the hard rhyolite, so we got a good look at both (see the two photos above). You can easily see the difference in the photos here. The path led down to Ranisar lake (featured photo). Very logical for an aqueduct to drain into a lake, I thought. The blue city and the fort can share this water. Wonderful planning against sieges which seldom happened.

We passed many different kinds of trees and bushes. Over the next few days I learnt to recognize the cactus-like bush of thhor (Euphorbia caducifolia), the leafless spurge. This was also my first view of the tangle of leafless stalks called the kheer khimp (Sarcostemma acidum) or rambling milkweed. The kheer is added to the name because of the milky sap it exudes from a broken stalk. There were stands of geedar tambaku (Verbascum chinense) and many other shrubs and herbs which I still cannot recognize. You can see some of them in the photos (do let me know if you can help me identify them). Many of these can also be found deeper in the Thar desert.

The desert park behind Mehrangarh with red welded tuff

Later on our walk we met Denzil again, when he showed us one of a pair of vagrant Eurasian Scops Owl which had nested in a thicket of trees. Walking back with him we learnt a little more about the effort involved in restoring the ecology of the area. That’s a story which newspapers have carried, so I won’t tell it here.

Camels’ delight!

The desert of full of spiny leafless green bushes. Leaves present a large surface to the sun and are great organs for photosynthesis, but they also lose a lot of water through transpiration. Green stalks can carry on photosynthesis while minimizing water loss. Of course, they also present a smaller surface to the sun. So this is a thorny problem (yes, I meant that) which plants have to solve: more photosynthesis or less water loss?

The local name for the green bush full of upright stalks which you can see in the photo above is khimp. The plant grows along the extreme arid zone which crosses from Mauritania to India through the Sahel, the Arabian desert and the Thar desert. A search for the origin of the botanical name Leptadenia pyrotechnica led me to this book, which claims that the name pyrotechnical comes from the observation that Bedouins use tinder to set alight the fibrous stems of this plant. Later compilations noted that the high fiber content of the stems has been used by people across its geographical range in various ways. Some have used it to make ropes, others in diet to cure anything from constipation to obesity. Although I never thought of breaking off a stem to look at the sap, I’m told that it gives a clear sap. This is probably one of the reasons why camels are said to be fond of it.

There is a claim that extracts from plant was found to be mildly damaging to liver cells in a lab. On the other hand it is said to be eaten. Browsing the net, I came across a recipe for cooking khimp. Here is a translation: “Cut the stems and boil them. Remove them from water and press to drain the liquid. Separately cook spices in oil and add the boiled stems. Add a little buttermilk to cook further, thickening it with besan (chickpea flour) as needed.” The double cooking of the stems probably serves not only to tenderize the material, but also to denature toxins. The pressing and draining may also remove any toxins.

They grow along with phog on dunes and other dry sandy places. In various countries around the world people are experimenting with using L. pyrotechnica as a biological barrier to the spreading of dunes. But when I stood on top some dunes and took the photo above, I did not know that this could also be a weapon against cancer.

Winter phog

The tall bush which you can see on the right hand edge of the featured photo is called phog in Hindi, and Calligonum polygonoides by botanists. Other clumps can be seen on further dunes. Each thicket can grow about as tall as a human, and spreads out in a circle. Unfortunately, I visited the Thar desert in winter, when one does not get to see the flower or berries of the phog. The flowers and buds are eaten as a raita, the shoot is used as feed for livestock and the root is used to make charcoal. The deep tap roots and lateral root system together contain a larger biomass than shoots.

As you can see from this panoramic shot, the plant grows very well in the extremely arid habitat of dunes where little else grows. As a result, it serves to stabilize the dunes. Over-exploitation of the plant to produce charcoal used by goldsmiths and local ironsmiths has begun to endanger the phog. There are attempts to propagate the plant through cultivation and replanting, but this has not been uniformly successful. Studies of competition between the phog and other varieties of desert grass shows that in more moist conditions the phog loses out. Consistent with this is the fact that growth of C. polygonoides changes soil properties less than other plants do.

Of more than 80 species of Calligonum recorded worldwide in arid areas of southern Europe, northern Africa, west and central Asia, only this one species grows in the Thar desert of India. A recent study found very high degree of genetic diversity in the phog population in Rajasthan. However, there was no geographical clustering of varieties. When I talked to an expert, I was told that the confused state of this first study makes this subject worth a second look. After reading the scant literature on this plant, I would be willing to do such a study if I had the expertise and the means.

Desert Hyacinth

I stumbled down the slip-face of a sand dune and heard Adesh call out to look to my right. There, poking out of the sand was a colourful spike: red with yellow flowers. “That’s a root parasite”, Adesh told me. Indeed it was a parasite, there was no green anywhere on it, so it could not possibly be synthesizing its own food. Since it was standing far from any visible plant, I was willing to take Adesh at his word. Later, when I read about the parasitic plant, the Desert Hyacinth or Cistanche tubulosa, I found that it is widespread, growing as far away as the Taklamakan and parts of the Arabian desert. It is said that the seeds are extremely hardy, and can remain alive for years, being triggered into growth when some root wanders nearby.

What was this one parasitizing? Looking around I could see only one tree nearby. You can see it in the photo above, behind the Desert Hyacinth. This is the ubiquitous Capparis decidua, the tree called ker. This bears the sour berry which is one of the ingredients of the desert food called ker sangri. The tree is highly branched. The branches are green, and there are seldom any leaves. I’d been very excited to spot a leaf emerging from a split in a stem earlier in the day. You can see that in the photo alongside. In any case, this was very likely to be the tree that the parasite was feeding upon. It makes sense that the roots of the ker tree range far in search of water, and therefore are vulnerable to parasites.

It seems that the Desert Hyacinth is used in traditional Chinese medicine as a cure for erectile dysfunction. I guess any upright and unbranched plant looks like it could be a cure for such matters. Since they are often in the mind, the “cure” could even work in a significant number of cases. A quick look at Google Scholar shows that several chemicals extracted from this parasite have interesting possible effects: from protecting the liver, slowing the onset of Alzheimer’s disease, to helping with diabetes.

Adesh pointed out another interesting thing which you can see in the featured photo: there is the track of a beetle which circles the parasitic plant before burrowing into the sand at the base of the flowering stalk. It was clearly after food. I wonder whether it was the host or the parasite which would become the beetle’s food. When you look closely, the desert is alive.