Just back from the moringa collection to collect leaves for genetic analysis and seeds for micro-RNAs. Here are some photos of flowers, fruits, and other things from June and August in the collection.
Lots of collection maintenance this month- planting new plants, erosion control moving grumpy plants to locations we hope they will like better. Hopefully lots more flowers and fruits to report next blooming season!
In addition to trying to understand the relationship between wild Moringa oleifera and the domesticated M. oleifera, unraveling the taxonomy of the oleifera complex involves understanding what is going on with Moringa concanensis. I had collected M. concanensis in Tamil Nadu years ago, and it was now time to start visiting other localities throughout the range of the species. This will be crucial to help determine whether M. oleifera truly has a wild oleifera ancestor or whether it was domesticated from some M. concanensis population. The populations in Rajasthan are about as far away as you can get from Tamil Nadu in the range of M. concanensis and are fairly close to the type locality in Baluchistan, in present-day Pakistan (though work remains to figure out where the type material actually comes from; my Pakistani colleague Wasif says he does not know where the "Lus Hills" are, so it may not be a name in current common usage).
Even though the species is fairly widespread in the Indian subcontinent, Rajasthan sticks out in the Moringa literature as being an area where M. concanensis occurs, possibly because there are two or three localities with very precise location information that have been repeated in the literature. For example, in Verdcourt's 1985 paper on the family, he cites "100 km from Jodhpur on the road to Pokharan," which has an appealing ring of precision to it.
In my 1998 field work in India, I ended up not having time to look for the species in Rajasthan and so it had always remained as a question in my mind as to what kind of habitat M. concanensis grows in in NW India. This is because the area between Jodhpur and Pokhran is very dry, with 300-200 mm rain per year. This in itself doesn't disqualify it as Moringa country-- Moringa habitats range from 100–1100 mm or so, with an average of about 500 mm annual precipitation (see Olson et al. 2013). But the vegetation and soils seem unlikely- open Acacia woodlands on very sandy soils, and even dunes. True, northeast African Moringa longituba and sometimes M. rivae are found on sandy soils with Acacia but there they are in rich tropical dry forest and even savannah and not such open and disturbed vegetation. What is clear is that the habitat of Moringa concanensis that I had seen in Tamil Nadu (see my photos here) was very different- dense deciduous tropical forest. The Rajasthan lowlands have been inhabited for millenia, so it's also hard to tell quite what the native vegetation would be. So, while the Pokhran Road locality is an often-repeated one, it seemed like an unlikely place to find Moringa concanensis. Indeed, Bhandari, in his very nice Flora of the Indian Desert gives more detail on the Pokhran Road plant: "A rare plant... A lonely very large tree was seen... 100 km from Jodhpur, along Jodhpur-Pokaran Road." The first edition of the Flora was in 1978; by the time we got to the locality, the moringa was long gone. There were none to be seen on the dunes and sandy flats, and locals assured us that there were none growing in the area. Pradip Krishen, author of the outsanding Trees of Delhi and Jungle Trees of Central India, has written a very nice booklet called The Small Plant Guide to Rao Jodha Desert Rock Park." The park is just below Jodhpur's spectacular and much-visited Mehrangarh Fort. It is a first-rate native botanical garden and should be on every visitor's list. His Guide says that Moringa concanensis is "capable of taking you completely by surprise when you see it in unlikely places in the desert." Neither Bhandari nor Krishen's descriptions make M. concanensis sound like a normal inhabitant of the deserty lowlands to the west of Jodhpur. We admittedly looked for only three days, but we were unable to find any between Jodhpur and Pokhran and around Jaisalmer. So we decided to look elsewhere, to see if we could find dry tropical forest more similar to that in which I had seen Moringa concanensis in Tamil Nadu.
Below are some photos of the common plants we saw in western Rajasthan.
From Google Earth, the best bet that we had located before heading into the field were woods in the Aravalli Hills. This very long range runs SW-NE through Rajasthan, visible as the tan swath below.
The Aravalli Hills have steep slopes that are difficult to cultivate and so still appeared to have some lowland tropical woodlands. So we spent a few days crisscrossing the range on small dirt roads, and what is immediately striking is that all of the towns in the hills without fail have Moringa concanensis trees growing both among the houses, and even more commonly, fringing millett and other agricultural fields.
This pattern was really conspicuous- no trees in the woods on the flats, and no M. concanensis trees in the towns of the flats either. In searching for the fragments of remaining forest, we found two kinds.
The first was disturbed Boswellia serrata woodland. Boswellia, the Indian cousin of frankinscence from the Horn of Africa and the Arabian Peninsula, seems to tolerate a fair amount of disturbance, and was very common on the lower slopes of hills and wherever people grazed their goats at moderate intensities. There were always plenty of Boswellia seedlings of all stages in these woods, showing that they are reproducing.
There were never Moringa concanensis in these Boswellia woods. So, we started looking for hillsides with forest but no Boswellias, and this proved a perfect indicator for M. concanensis. Just as in Tamil Nadu, we found it in relatively undisturbed dense tropical dry forest, usually on steep rocky slopes, but always where grazing was relatively light or absent because of inaccessibility or just distance from towns. This seeming intolerance for disturbance is similar to the putatively wild Moringa oleifera trees in Punjab, which also seemed to grow only in the areas of least disturbance. Below are some photos of M. concanensis in Aravalli woods.
Here are some images of the plants that grew with Moringa concanensis:
The leaves of Moringa concanensis are distinctive for their relatively large leaflets, long petiolules, and for having much longer stretches of leaf nodes with leaflet pairs (rather than pinnae) than M. oleifera. It is not true, as is often repeated, that M. concanensis is bipinnate and M. oleifera is tripinnate, but it's close. Moringa concanensis is often bipinnate and always has much fewer tripinnate elements than M. oleifera. Moringa oleifera is often 4-pinnate and always has lots of tripinnate elements on large leaves.
As compared to Moringa oleifera, M. concanensis almost always has distinctive patterns of pitting on the seed testa. This is uncommon in domestic M. oleifera though there is a lot of variation within the species.
Moringa concanensis definitely seems to make up a natural part of the dense tropical dry woodlands in the Aravalli Hills. Areas with sufficiently low disturbance for Moringa concanensis aren't hyperabundant, but we were able to find them dependably in the area we searched, between Pushkar and Deogarh. We didn't make it as far south as we would have liked, but they seem to grow all the way down the Aravalli. For example, they are reported in the hills in Gujarat, just over the border from Rajasthan: www.eastgfd.com/
Whether Moringa concanensis ever grew in large stands on the flats is anyone's guess. Given reports of occasional trees on the flats, it seems possible. These might just be occasional waifs, and it's striking that they are never grown in the towns and fields of the flats, but always in the hills. With their dense and long standing human habitation, these uncertainties are just a part of biology in the dry tropics.
Bhandari, M. M. 1995. Flora of the Indian Desert. MPS Repros, Jodhpur.
Olson, M. E., J. A. Rosell, C. León, S. Zamora, A. Weeks, L. O. Alvarado-Cárdenas, N. I. Cacho, and J. Grant. 2013. Convergent vessel diameter-stem diameter scaling across five clades of New- and Old- World eudicots from desert to rain forest. International Journal of Plant Sciences 174: 1062–1078.
In the flurry of exploration of the early 1800s, botanists often named interesting variants as new species, not necessarily because they were convinced that they are real species, but to flag them as worthy of further study. Such seems to be the case of a taxon called Moringa sylvestris.
In 1826, in the Memoirs of the Wernerian Natural History Society, Scottish physician and talented natural historian Francis Buchanan-Hamilton scoffed at the descriptions of what we now call Moringa oleifera by Linneaus and others. In the late 1700s and early 1800s, there were so many new plants being discovered and described, often from such fragmentary material, that it was often hard to know to what plant a given name applied. Buchanan-Hamilton got so exasperated with the errors of previous authors -- like Linneaus's mistaking Moringa for a legume, and misinterpretations of the staminodes of Moringa as damaged anthers -- that he regarded all previous moringa names, including M. oleifera, as so ambiguous as to be useless. To provide what he saw as order to the situation, he described two taxa, M. domestica and M. sylvestris. Neither names are used today, and both are regarded as M. oleifera.
But he did succeed in highlighting an intriguing situation. First, his "Moringa sylvestris" is morphologically distinctive- with its uniformly pale seeds with spongy seed coats, it's unlike the usual domestic M. oleifera, which has dark seed bodies and thin seed coats. It is more like the putatively wild M. oleiferas from Punjab, and from what we heard people in Punjab and Uttarakhand refer to as "inedible" moringa. You can see the pale seeds on the specimen below.
Even more intriguingly, Buchanan-Hamilton notes (p. 369) "I have... seen two kinds of this tree, one growing near villages, and the other in woods," the former being his M. domestica and the latter M. sylvestris, and the area being that around Patna, in the central northern Indian state of Bihar. Seeming to corroborate the idea of wild moringas in the area, almost a century later, Henry Haselfoot Haines, in his generally excellent Flora of Bihar and Orissa notes that Moringa oleifera is found wild "along riversides" in the lower valleys of the Sameshwar Hills (in Part I, from 1925), which are in Bihar about 200 km northwest of Patna, and that it grows "Wild in the valleys of the Ramnagar [Sameshwar] Hills, along river beds !" (in Part III, from 1922). The exclamation point isn't because he was astonished; it's a botanical convention that means that the author saw something for himself, usually a given herbarium specimen, but in this case living plants.
It is for these reasons that, after Punjab, Bihar has had the reputation of being special as far as moringa is concerned. From the Buchanan-Hamilton specimens, it does seem that there is an interesting morphological variant in the area (his "M. sylvestris") that seems not unlike the putatively wild plants from Punjab, and from his report as well as that of Haines, it seems that there might even be wild plants in Bihar. The Sameshwar Hills, moreover, are part of the great Shivalik range, on whose low slopes is where the wild moringas of Punjab are found, making it seem possible that wild M. oleifera might reach this far east. The rainfall -- 1500 to 2000 mm -- seemed awfully high for any moringa species, but in botanical exploration there is no alternative- you need to go and have a look.
So, with this in mind, we hopped on a plane from Delhi to Patna, and we weren't disappointed.
As soon as we got to Patna, Garima and I took to the streets to see what moringas were being cultivated around town. We found some typical domestic oleifera, but then found some very robust plants, with pale apple green, pubescent leaves, an aggressively bitter taste, large leaves on thick terminal twigs, and pale, concolorous seeds with spongy testas: we had rediscovered Buchanan-Hamilton's "Moringa sylvestris" variant nearly 200 years after he described it from the vicinity of Patna. Now the question was whether it did indeed grow wild in the Sameshwar hills, as Haines assured.
On the day-long drive north to the Sameshwar Hills, it was clear that both variants- what Buchanan-Hamilton would call both the sylvestris and domestica variants- were cultivated in all of the towns and villages. Practically no house was without at least one tree, and almost all of the rice paddies and millet fields had at least a few moringas fringing them.
Having convinced ourselves of the presence throughout NW Bihar of what Buchanan-Hamilton called the "sylvestris" sort of Moringa oleifera, we then headed into the lower valleys and forests to look into Haines's report of wild plants on riversides. We found plenty of them, but always on the edges of cultivated fields, like those in the photos below.
There weren't any Moringas in the forest proper. We saw three forest types in the lowlands. One was tall deciduous or subdeciduous tropical forest with trees 20 m or so tall, like Haldina (Rubiaceae), big-leaved Terminalias (Combretaceae), lots of Wrightia (Apocynaceae), Aegle (Rutaceae), Ficus, etc., and some areas with Shorea (Dipterocarpaceae). I was excited to see Leea (Leeaceae/Vitaceae) in the understory- one of the few self-supporting taxa in a generally lianescent lineage. Pretty forest and very interesting, but way too tall and shady for moringas.
In some places, the forest was even moister and taller, with lots of rattan palms (Calamus). Really interesting but even wetter and shadier, even less appropriate for moringas.
The third forest type was an open, savannah-like woodland with Buchanania (Anacardiaceae) and a small pinnate leaved palm on hard laterite. Adding a savannah like touch, this was the only vegetation type where we saw termite mounds here. The black trunks of the plants suggest that the area burns, and moringas aren't fire resistant. These fires might not be natural, of course, but there again weren't any moringas in sight.
So, there were definitely no moringas in the woods. That left the riversides mentioned by Haines. Maybe the moringas were on eroded riversides. So, we took a good look at the riversides and steep eroded slopes in the lowland river valleys.
We found plenty of riverside eroded slopes, open and sunny the way a moringa might like. But whenever forest would establish on these slopes, it was the tall jungle. Not only were there no moringas anywhere, there were no habitats for a dry loving plant like moringa to survive in.
So, to summarize, moringas were everywhere in the villages of the Samewshar Hills, but definitely not in the wild habitats. Our conclusion: Haines's riverside plants were associated with humans. Given that they were often on the edges of fields, often fallow ones or ones invaded with weedy trees, it would be easy for someone not paying all his attention to moringa (Haines was, after all, assembling the flora of two whole vast states) to take away the impression of their being wild. But even the riverside habitat would be fishy; no moringas are dependably riparian or even prefer to grow on floodplains (M. arborea does grow in a dry, rocky gully but probably doesn't see water very often). So, we were convinced that there are no wild moringas in the area. Where Buchanan-Hamilton's "Moringa sylvestris" comes from is anyone's guess- perhaps imported long ago from Punjab? Garima's data should shed light on the issue.
This year's July India trip began with a visit with collaborators and talented geneticists R. Geeta and Priya Panjabi-Massand from the Botany Department of the University of Delhi. They have just recruited Garima, a PhD student who is working on genetic variation in Moringa oleifera worldwide, but with emphasis on India.
This is the way it should be: M. oleifera is an Indian plant, and though there is a lot of research on genetic and morphological variation, features of applied interest, etc. in many parts of the world, the fact is that India is where the really important research will take place. This is because the genetic diversity there is almost certainly higher than anywhere else on earth. Think of the situation this way. If moringa breeders wish to maximize some feature of interest, like protein content or anti-cancer activity, where is the best place to do so? You could start with the moringas in Ghana, or in Mexico, or in the Philippines; you will be starting with a very narrow range of variation. This means that the response to artificial selection will be slow and possibly limited. But if you start with a much wider range of variation, such as might be found in parts of India, then response to selection will be faster and possibly even exceed what could be accomplished elsewhere.
So, Garima will be sampling from across India and using the samples in the International Moringa Germplasm Collection to generate the first rough scale map of the genetic variation across Moringa oleifera. This is where all of our moringa research needs to begin. It will be a privilege and a pleasure to work with her over the coming years. As a first step, we headed out into the field, as I'll describe in subsequent posts.
In addition to the fieldwork, Julieta designed a very fun course on plant functional traits and the fate of carbon in forests, that we gave together in the Botany Dept at U. of Delhi, to about 50 master's and Phd students in their large and active postgraduate program. As you can see from some of the photos below, it was a blast.
In a recent article that you can read here, Rachel Cernasky looks at "superfood" fads and asks whether they can have benefits, especially to the people who live where they are being produced.
People in rich countries already have an abundance of nutritious foods and access to the most scientifically supported nutraceuticals. So a lot of the "superfoods" fads might simply be superfluously bringing things that they already have in exotic packages.
But there are two possible exceptions. One is a situation in which a food brings nothing really novel to the diet but its consumption helps support needy communities. The other is one in which the food is "super" in that it really does bring something novel. Moringa, with its nutrient and nutraceutical profile, might be such a novel plant, mainly for the tropics but maybe even for the temperate world as well. And there might be situations in which it meets the first situation as well, when its sale to rich countries provides a useful cash supplement to tropical communities.
The jury is out on both accounts, but Cernasky's article is an interesting look at the issue. She interviewed me for the article, and getting me in a rare lucid moment, she reproduces my rule of thumb for the validity of a moringa product: the closer it is to real, fresh, unadulterated, unprocessed moringa leaves, the better. From this point of view, moringa products are on a spectrum: on one end, fresh leaves, followed by frozen ones. Then come dry leaves and ground, dried leaf. At the other, bogus, end, are tinctures, extracts, pills, and all manner of other untested and unstudied and maybe even harmful preparations that are maximally far from a plate of fresh moringa leaves.
The debate continues regarding how, and even whether, to commercialize moringa, and Cernasky's provides food for the debate.
I keep some seedlings that I want to baby here in Mexico City. But growing them outside is out of the question because it's way too cold and dry here for moringas. Mexico City is at 2000 meters above sea level, which means that it's a very pleasant climate for humans but leaves moringas struggling.
So, I grow them under lights in a heated growth chamber. The temperature oscillates all the time between 28 and 29 degrees celsius, a good toasty moringa temperature. The lights are on 14 hours a day, and I have never bothered to change the photoperiod between the wet and the dry season. Even so, the plants are just coming out of their end-of-the-dry-season semi-dormant rattiness, or even full dormancy. How they know what time of year it is is frankly amazing.
Five months after Hurricane Patricia plowed directly over the Moringa collection, the plants are looking good. We lost about 30% of the plants that were planted out in the botanical garden, mostly the smaller ones. Some of the larger plants went dormant and are still leafless. Though they have never done this before, and have kept their leaves through the dry season sans hurricane, in general leaflessness is normal for this time of year, which is the height of the dry season. And like many plants of tropical drylands, Moringa species flower at the height of the dry season and shed their seeds just before the rains come. Despite the battering they took back in October, some plants are flowering for the first time here. Moringa oleifera, M. drouhardii, M. concanensis, M. stenopetala, M. rivae, and M. longituba have flowered before, but it’s the first time that we’ll have more than one M. longituba and more than one M. rivae in flower at the same time. I will be in the field when they open, but I am trusting humminbirds and bees to do the right thing. It would be the first time we get seed from these species from our own plants.
Just as exciting, it’s the first time that M. borziana flowers in the collection (they nearly did in October/November, but Patricia blew all the buds off). Not only that, but it looks like three plants will bloom at the same time, so again fingers are crossed for seeds.
Also, here are what as far as I know are the first photographs ever of Moringa hildebrandtii flowers, which I had never seen before. They are described in the literature as being slightly bilaterally symmetrical, but this is not really evident in these flowers. What is interesting and unique in the family is the long “claw” (the petal “stalk”), and the very short “limb” (the “petal” part of the petal). Not only is the limb short, but it withers and turns brown almost immediately after opening. The result is a vivid combination of yellows and browns in the floral display of Moringa hildebrandtii.
Alberto’s Moringa oleifera experiment on the relationship between plant size, leaf area, and stem length got flattened in October and has come back nicely. He and Diana have started harvesting plants and have made excellent progress. Hopefully we’ll have a manuscript by the end of the year.
Finally, a few photos of the plants in the collection plus some local animals, in this case an anole lizard Anolis nebulosus I think, which is common in the collection, plus some ibises, which I had seen in the area but never in the collection itself.
The Malagasy moringas M. drouhardii and to a lesser extent M. hildebrandtii put up fairly well with cool weather and as a result are sometimes grown to good ornamental effect in temperate areas like southern California. The first photo is of Moringa drouhardii and Moringa hildebrandtii in the Madagascar Spiny Forest section of the Los Angeles County Arboretum.
The others are from The Huntington, a magnificent botanical garden in San Marino, CA. What got me was that their Madagascar section is heated by outdoor gas heaters. This struck me as a bit excessive--- taking plants from the dry tropics where the people are poor and bringing them to a rich but cold country where to keep them alive they require a massive energy investment, all so the rich folks can admire them. Is this really the way we should be burning off our irreplaceable heritage of fossil fuels?
One month after the hurricane, the biggest and the smallest plants are sprouting back. Practically everything in the stem diameter range of about 1-3 cm was ripped out of the ground or was so thrashed back and forth by the wind that the root-stem junction was destroyed and the plants died. At this point we have lost about 15% of the plants planted out in the botanical garden. Everything in pots survived because they rode out the storm safe inside a sturdy house.
Moringa wood makes great kindling to get a fire started. This is a good thing because we have a hell of a lot of it on the ground. Here are some photos of trees resprouting, moringa kindling, and a moringa pizza cooked in a moringa wood-fired oven.
I had high hopes for the "First International Symposium (entitled "Moringa: A Decade of Advances in Research and Development") in Manila, Philippines November 15-18, 2015. My hope was justified because conference brought together Moringaphiles from 50 countries around the world as was associated with serious global organizations like the International Society for Horticultural Science and the AVRDC- World Vegetable Center. And it was indeed great to meet so many moringaphiles, many of whom I had known for years via email but had never met in person. But scientifically the conference wasn't quite what I had hoped.
My hope was that I would be able to drum up a bunch of collaborative efforts to study the diversity in the moringa germplasm collection. The point of the talk that I gave was that with modern communication technology, to say nothing of the ability to travel so easily, it is time for moringa research to become global. What I mean by global is that it is time to survey the full genetic diversity across Moringa oleifera and the genus at large and time to stop carrying out local little studies of whatever moringa material happens to be growing outside the lab. This is just what the International Moringa Germplasm Collection is designed to do. Now that the plants are big enough to harvest plenty of leaves from, it's time to use them to their full potential. Let's do it, was the invitation of my talk.
And in response I got... virtually nothing. I got two requests of the "please send me all of your 20 years of work no strings attached and for no real reason" type, but no interest in producing high quality moringa science for publication in reputable journals. To be fair, a lot of the people attending the meeting were not scientists but farmers and people interested in commercializing Moringa, but still I expected at least some scientific discussion.
So, let me reiterate my invitation: please, let's use the material in the Collection to drive moringa research with a truly global scope and relevance. Let's publish moringa research in the best journals we can, to bring moringa out of its regional-journals-with-low-or-no-impact-factor obscurity and into the mainstream. Get in touch, let's design a study, and I can send you material immediately!
In the meantime, here are a few photos from the meeting...
Dr. Mark E. Olson is a researcher at Mexico's national university and an expert on the biology of the genus Moringa