Tuesday, February 16, 2016

Moving Plants

All humans move plants, most often by accident and sometimes with intent. Humans, unfortunately, are only rarely moved by plants. 

The history of plant movements have often been difficult to establish. In the past the only way to tell a plant's homeland was to look for the number of related species in a region to provide clues on origin. This idea was firmly established by Nikolai Vavilov before being sent off to his unfortunate death in Siberia. Today, genetic relatedness of plants can be examined by comparing the similarity of chosen DNA sequences and among individuals of a species those sequence locations that are most variable. Some recent studies on individual plants and their relatedness have provided some very interesting glimpses into human history. A study on baobabs in India and their geographical origins in East Africa established by a study in 2015 and that of coconuts in 2011 are hopefully just the beginnings. These demonstrate ancient human movements which have never received much attention in story-tellings of history. 

Unfortunately there are a lot of older crank ideas that can be difficult for untrained readers to separate. I recently stumbled on a book by Grafton Elliot Smith, a Fullerian professor who succeeded J.B.S.Haldane but descended into crankdom. The book "Elephants and Ethnologists" (1924) can be found online and it is just one among several similar works by Smith. It appears that Smith used a skewed and misapplied cousin of Dollo's Law. According to him, cultural innovation tended to occur only once and that they were then carried on with human migrations. Smith was subsequently labelled a "hyperdiffusionist", a disparaging term used by ethnologists. When he saw illustrations of Mayan sculpture he envisioned an elephant where others saw at best a stylized tapir. Not only were they elephants, they were Asian elephants, complete with mahouts and Indian-style goads and he saw this as definite evidence for an ancient connection between India and the Americas! An idea that would please some modern-day cranks and zealots.

Smith's idea of the elephant as emphasised by him.
The actual Stela in question
 "Fanciful" is the current consensus view on most of Smith's ideas, but let's get back to plants. 

I happened to visit Chikmagalur recently and revisited the beautiful temples of Belur on the way. The "Archaeological Survey of India-approved" guide at the temple did not flinch when he described an object in one of the hands of a carving as being maize. He said maize was a symbol of prosperity. Now maize is a crop that was imported to India and by most accounts only after the Portuguese sea incursions into India in 1492. In the late 1990s, a Swedish researcher identified similar  carvings (actually another one at Somnathpur) from 12th century temples in Karnataka as being maize cobs. It was subsequently debunked by several Indian researchers from IARI and from the University of Agricultural Sciences where I was then studying. An alternate view is that the object is a mukthaphala, an imaginary fruit made up of pearls.
Somnathpur carvings. The figures to the
left and right hold the puported cobs.
(Photo: G41rn8)

The pre-Columbian oceanic trade ideas however do not end with these two cases from India. The third story (and historically the first, from 1879) is that of the sitaphal or custard apple. The founder of the Archaeological Survey of India, Alexander Cunningham, described a fruit in one of the carvings from Bharhut, a fruit that he identified as custard-apple. The custard-apple and its relatives are all from the New World. The Bharhut Stupa is dated to 200 BC and the custard-apple, as quickly pointed out by others, could only have been in India post-1492. The Hobson-Jobson has a long entry on the custard apple that covers the situation well. In 2009, a study raised the possibility of custard apples in ancient India. The ancient carbonized evidence is hard to evaluate unless one has examined all the possible plant seeds and what remains of their microstructure. The researchers however establish a date of about 2000 B.C. for the carbonized remains and attempt to demonstrate that it looks like the seeds of sitaphal. The jury is still out.
I was quite surprised that there are not many writings that synthesize and comment on the history of these ideas on the Internet and somewhat oddly I found no mention of these three cases in the relevant Wikipedia article (naturally, fixed now with an entire new section) - pre-Columbian trans-oceanic contact theories

There seems to be value for someone to put together a collation of plant introductions to India along with sources, dates and locations of introduction. Some of the old specimens of introduced plants may well be worthy of further study.

Introduction dates
  • Pithecollobium dulce - Portuguese introduction from Mexico to Philippines and India on the way in the 15th or 16th century. The species was described from specimens taken from the Coromandel region (ie type locality outside native range) by William Roxburgh.
  • Eucalyptus globulus? - There are some claims that Tipu planted the first of these (See my post on this topic).  It appears that the first person to move eucalyptus plants (probably E. globulosum) out of Australia was  Jacques Labillardi√®re. Labillardiere was surprized by the size of the trees in Tasmania. The lowest branches were 60 m above the ground and the trunks were 9 m in diameter (27 m circumference). He saw flowers through a telescope and had some flowering branches shot down with guns! (original source in French) His ship was seized by the British in Java and that was around 1795 or so and released in 1796. All subsequent movements seem to have been post 1800 (ie after Tipu's death). If Tipu Sultan did indeed plant the Eucalyptus here he must have got it via the French through the Labillardi√®re shipment.  The Nilgiris were apparently planted up starting with the work of Captain Frederick Cotton (Madras Engineers) at Gayton Park(?)/Woodcote Estate in 1843.
  • Muntingia calabura - when? - I suspect that flowerpecker populations boomed after this.
  • Delonix regia - when?
  • In 1857, Mr New from Kew was made Superintendent of Lalbagh and he introduced in the following years several Australian plants from Kew including Araucaria, Eucalyptus, Grevillea, Dalbergia and Casuarina. Mulberry plant varieties were introduced in 1862 by Signor de Vicchy. The Hebbal Butts plantation was establised around 1886 by Cameron along with Mr Rickets, Conservator of Forests, who became Superintendent of Lalbagh after New's death - rain trees, ceara rubber (Manihot glaziovii), and shingle trees(?). Apparently Rickets was also involved in introducing a variety of potato (kidney variety) which got named as "Ricket". -from Krumbiegel's introduction to "Report on the progress of Agriculture in Mysore" (1939) 

Further reading
  • Johannessen, Carl L.; Parker, Anne Z. (1989). "Maize ears sculptured in 12th and 13th century A.D. India as indicators of pre-columbian diffusion". Economic Botany 43 (2): 164–180.
  • Payak, M.M.; Sachan, J.K.S (1993). "Maize ears not sculpted in 13th century Somnathpur temple in India". Economic Botany 47 (2): 202–205. 
  • Pokharia, Anil Kumar; Sekar, B.; Pal, Jagannath; Srivastava, Alka (2009). "Possible evidence of pre-Columbian transoceaic voyages based on conventional LSC and AMS 14C dating of associated charcoal and a carbonized seed of custard apple (Annona squamosa L.)" Radiocarbon 51 (3): 923–930. - Also see
  • Veena, T.; Sigamani, N. (1991). "Do objects in friezes of Somnathpur temple (1286 AD) in South India represent maize ears?". Current Science 61 (6): 395–397.