Volume 108 1999 > Volume 108, No. 4 > Maori gourds: An American connection?, by Michael K. Burtenshaw, p 427-433
MĀORI GOURDS: AN AMERICAN CONNECTION?
Maori varieties of hue, the calabash or bottle gourd, share some morphological characteristics with the American subspecies, Lagenaria siceraria ssp., suggesting that some varieties can claim American parentage. With the resurgence of interest in growing the plant amongst crafts people and other gourd enthusiasts, the danger of crossing and contamination with imported varieties increases the risk of losing genetically true Māori varieties and other ethnic varieties. It is important that genetic analysis of the remaining varieties occurs before this evidence of a possible American connection is diluted or lost. A comparative DNA analysis of archaeological remains with present-day Māori varieties could also help determine the extent to which these are related and shed some light on early post-European plant introductions.
Lagenaria siceraria is thought to be one of the first plants domesticated by humans in tropical areas (Heiser 1973a:121). Its usefulness as a food and medicinal plant, as well as multiple uses for the hard shell of the dried fruit, ensured the plant's continued cultivation for thousands of years by different peoples throughout the world. The hollow hard shell of the fruit has been used for a wide range of domestic containers, fishing floats, musical instruments, masks, phallocrypts and for many other purposes. The cultivation of the gourd has even been postulated as progenitor of more elaborate agricultural systems (Lathrap 1977).
Like the kumara, the gourd is honoured in Māori myth with a personified form. The gourd is believed to have originated with Pu-te-hue, who was one of the offspring of Tane (Best 1976:245).
There are two recognised subspecies of Lagenaria siceraria (Heiser 1973a:127). Heiser based this classification of subspecies on morphological differences in leaves, flowers and seeds. Lagenaria siceraria ssp. siceraria have leaves entire, crenate or round-lobed; flowers generally small to medium sized, calyx lobes usually short and broad; seeds generally less than twice as long as broad, with or without corky wings; longitudinally lined or smooth, lines seldom pubescent, with or without ears, generally dark in colour. This subspecies originated in Africa before spreading to the Americas.
Lagenaria siceraria ssp. asiatica from Asia has leaves rounded-lobed or laciniate-lobed; flowers usually large, calyx lobes long and narrow; seeds generally more then twice as long as broad, with or without corky wings, longitudinally lined, lines sometimes pubescent, usually eared, gray, gray-brown, or white in colour.
Heiser (1973a:123) does not use an earlier classification feature based on fruit colour and thickness of the fruit wall (Kobiakova 1930) because his examination did not show significant differences between the subspecies he examined. A variety of different fruit shapes occurs in both subspecies and, while this feature is not useful in separating the two subspecies, certain fruit shapes tend to predominate in different world regions (Heiser 1973a:123).- 428
Interestingly, present-day Māori varieties I have grown can be distinguished by the shape of the fruit produced. These varieties appear to have been selected on the basis of the fruit shape and to a lesser extent size. The varieties produce fruit shapes typical of the museum huewai illustrated by Maingay (1985:193), although I am yet to grow Māori gourds large enough for use as a tahahuahua found in museum specimens. Of the six present-day Māori varieties grown by me to date, two were obtained from Māori friends and four were obtained from Koanga Garden's heritage seed collection. All are genuinely believed to be original Māori varieties.
Heiser classed the Polynesian and New Zealand gourd as nearest the Asian subspecies but points out that this is based on only two samples from Niue and New Zealand (Heiser 1979:97). New Guinea gourds presented an anomaly because the small sample of gourds examined were more similar to the gourds from Africa and America (Heiser 1973b:318).
In her comprehensive study Te Hue: People and a Plant, Maingay (1985:269) suggests that further research could add to the understanding of prehistoric technology, agriculture and early contacts between Pacific peoples. This study of existing Māori varieties and surviving archaeological evidence indicated the possibility that New Zealand and other Eastern Polynesian gourds were not descended from purely Asian stock, and that American or New Guinea gourds could have been involved (Maingay 1985:103-4).
The two archaeological seeds of prehistoric provenance examined by Maingay (1985:102-3) had the broad short dimension of L. siceraria ssp. siceraria while - 429 differing considerably from each other with respect to surface lines and ears. Maingay (1985:101) found the dimensions of most New Zealand seed were most typical of L. siceraria ssp. asiatica with two exceptions that exhibited L. siceraria ssp. siceraria features. Leaf lobes and leaf margin serration appeared to fall between L. siceraria ssp. siceraria and L. siceraria ssp. asiatica. Flower size was quite large approximating L. siceraria ssp. asiatica but calyx lobes were small, more in the L. siceraria ssp. siceraria range (Maingay 1985:102).
Six present-day Māori varieties grown by me have leaf lobes more closely resembling L. siceraria ssp siceraria, but with slightly serrated margins. So far I have been unable to authenticate their origin as true Māori varieties, but the leaf shapes of my six Māori varieties were remarkably similar to leaf tracings of New Zealand gourds by Maingay (1985:282-83), suggesting genetic continuity in these Māori varieties at least in respect of leaf shape. They were distinctly different to the “Italian Edible” variety where the leaf was laciniate and lobed, typical of the Asian subspecies. It was not until I saw these varieties growing together that the obvious difference in leaf shape registered. Disregarding the serrated rather than crenate leaf margins, my present-day Māori varieties are typical of L. siceraria ssp. siceraria. Maingay's (1985:284) Polynesian and Hawaiian specimens showed leaf shapes most closely resembling my L. siceraria ssp. asiatica “Italian Edible”.
One of my Māori varieties had crenate margins as well as seed features of brown colour, ears and pubescent surface lines which classes it as L. siceraria ssp. siceraria. The seed colour and dimensions of my other varieties were more typical of L. siceraria ssp. asiatica. It is worth noting the difficulty I have had so far in making judgments when analysing some of the morphological features. This may affect the validity of comparisons. I have had only one season of practice. Maingay (1985:90) notes a similar difficulty with reference to scoring leaf lobes and leaf margins; fortunately she has left a clear record of how she conducted morphological measurements. The judgment difficulties inherent in establishing reliable measurements for morphological comparisons is one reason I am keen to see DNA analysis of the subspecies and varieties occur.
A comparative DNA analysis of present-day Māori varieties with pre-European archaeological remains might also give some clues on the genetic continuity in these varieties. It is possible to sequence DNA from museum gourds with minimal damage to specimens. While there is no guarantee comparisons would necessarily be meaningful (P. Garnock-Iones pers. comm.), any successful comparisons would provide valuable information on the extent to which genetically true Māori varieties have survived. Wider analysis might also give general indications as to the origin of varieties introduced in the early years of European contact.
Archaeological evidence, usually in the form of gourd fragments, has been found at a number of cave and swamp sites in New Zealand. Maingay (1985:227-46) has described archaeological evidence of gourd sherd and seed remains from New Zealand sites. Dates range from 13th to 14th centuries at Kohika in the Bay of Plenty to 17th to 18th centuries at the Waihora rock shelter. Many of the gourd sherds are of the peduncle or stalk ends which tend to be thicker and were often discarded when a bowl was made from a gourd. Gourd nguru or nose flutes made - 430 from neck of gourds were recovered at Kauri Point Swamp. Mäori gourds are also well represented in New Zealand museum collections.
On the matter of cultural diffusion and migration of peoples, much has been written about plants and their relationship with people. Whether the gourd floated by natural means from Africa to America or whether it was carried there by people has been widely debated and is well summarised by Heiser (1979:99-117). In Polynesia, ethnobotanical clues to the possible settlement of Eastern Polynesia by American Indians are still being reported (Langdon 1996:185-200). The northwestern South American origin of the Polynesian kumara is accepted as fact (Yen 1974, O'Brien 1972). O'Brien (1972:356-61) also makes a case for the pre-European transfer of the sweet potato from Polynesia to Melanesia then to New Guinea. It is possible that Lagenaria siceraria ssp. siceraria accompanied the kumara on the journey to New Guinea and this may explain the African and American features evident in the New Guinea plants (Heiser 1973b).
Possible scenarios for the occurrence in Māori varieties of some morphological characteristics similar to the African and American subspecies, Lagenaria siceraria ssp. siceraria, mirror some of the prehistoric hypotheses Yen (1974:2-3) gives for the kumara. Scenarios to be considered are as follows:
Transoceanic dispersal by natural processes remains a strong contender for both gourds and kumara. On the one hand, possibly kumara seed was spread by birds, but the size of gourd seeds prohibit this as viable explanation for its arrival. On the other hand, gourds float very well and the seeds remain viable long enough for it to drift considerable distances. Kumara seed remain viable for a considerable period of time and are impervious to salt water. While the seeds themselves do not float, the seed capsule does (Sauer 1993:41). Consequently, the argument for natural dispersion from America to some point in Eastern Polynesia or Hawai'i is a strong one.- 431
Buck (1938:314) suggests that the gourd could have been introduced to South America from Polynesia on same journey that procured the kumara from South America. This supposition is not supported by the evidence available today that dates archaeological gourd remains on the Peruvian coast in South America from 4000 B.C. and from Mexico at about 7000 B.C. (Sauer 1993:52).
Whistler (1991:43) has suggested that Lagenaria siceraria was misidentified in Western Polynesia and confused with the wax gourd, Benincasa hipida. As a result of this evidence he suggests that Lagenaria siceraria was instead introduced into Eastern Polynesia via South America at the same time as the kumara (Whistler 1991:52).
Yen (1971:340) says the strongest indication of American contact is found in the blood group genetics study by Simmons (1966) which concludes that the present-day Polynesian blood groups have resulted from contributions derived from Indonesia, Western Polynesia and South America. Yen (1974:264-67) points out that theories postulating Peruvian voyages to Polynesia do not account for the absence of important South American food plants such as maize and Phaseolus beans. One might argue that Polynesian visitors to western South America would be more familiar with root crops such as kumara. Yet, Polynesian visitors would have certainly recognised the gourd and have known its usefulness.
As the years go by enthusiasts have continued to grow and save seed of present-day Māori hue varieties, but with each season the chances of crop failure or cross pollination increases the risk that these varieties may disappear. Concurrently the proliferation of Internet sites belonging to gourd growers, gourd artists and gourd forums, to name but a few, indicate increasing contemporary interest in this ancient plant. Ironically, as seed is swapped and traded by these present-day enthusiasts the danger of losing the original indigenous varieties increases.
Today DNA “finger printing” techniques are well developed and a number of different methods are available. The simplest is DNA sequencing, but this requires finding a DNA sequence that differs between a range of populations. There are several less direct methods such as RAPDs (Random Amplified Polymorphic DNA), microsatellites, restriction enzyme fragments, ISSRs and allozymes. Allozymes are cheapest but DNA has the advantage of requiring only small amounts that can often be obtained from herbarium sheets (P. Garnock-Jones pers. comm.).
RAPD fingerprints of nine kumara cultivars, including three pre-European cultivars, revealed that two of the pre-European cultivars were closely related while the third was distinct (Harvey et al. 1997:484). This suggests a separate introduction for at least one kumara pre-European cultivar.
Similar results might be expected for Māori gourd varieties. While Māori have different names relating to gourd fruit and size (Best 1976:247), there is no clear historical evidence that the plants themselves were regarded as different varieties. DNA analysis could also throw some light on the relationships between present-day Māori varieties and archaeological remains. As a referee has commented “detection of ‘genetically true’ Māori varieties of hue is a difficult task because there has been over 200 years of crossing and contamination through the introduction of bottle gourds from across the globe” (Anonymous referee, pers. comm.). However, - 432 unless a start is made this important botanical evidence relating to Māori history may never be unravelled.
In conclusion, it is my hope that this short communication may inspire interest in and support for research into DNA analysis of Māori gourd varieties. The results may show these varieties have definite connections to Asia or South America. The data could well reveal the incidence of separate introductions of Lagenaria siceraria. Genetic comparison of archaeological evidence and present-day Māori varieties may show if hue varieties have remained genetically true and the extent to which the gene pool has changed as a result of European introductions. At the least this will increase our understanding of the origin of Māori gourds. By association the results may help improve our understanding of the origin of kumara and may perhaps offer some further contribution to our knowledge of the origins and migrations of prehistoric Polynesians.
I would like to acknowledge the assistance of Jenny Quilliam of Otaki for helping grow gourd varieties I have collected. Thanks also to Phil Garnock-Jones, Professor of Plant Science, School of Biological Sciences, Victoria University of Wellington for technical advice on aspects of DNA analysis.