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.
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.
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.
References
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.