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Carlos Magdalena, RBG Kew, Photo

The Australian Form of
Nymphaea nouchali -
Is it a unique species?

by Andre Leu, Queensland, Australia
Click images to enlarge

This article questions the current taxonomy on this plant and proposes that it is either an undescribed species or a distinct subspecies of N. nouchali.

Nymphaea nouchali is the only waterlily in the subgenus of Brachyceras that occurs naturally in Australia. The majority of endemic Australian waterlilies are in two subgenera, Anecphya and the recently described Confluetes. These are unique to Australia and its near neighbours.

N. nouchali is found in a very small area of Australia. Its distribution is limited to the coastal strip of northeast Queensland between latitudes 15 to 18 degrees south. This is many thousands of kilometres from the nearest Brachyceras relatives that occur in Asia. Due to its isolation from other species in its subgenus this population has to be genetically very pure.

It can be abundant where it is found though there are not a lot of locations. It grows in very shallow water usually no deeper than 30 cm (12 "). Some of these locations are ephemeral, drying up in the dry season. However N. nouchali tends to go dormant in the cooler months where it grows in permanent water. 

The Australian form of N. nouchali is unique in that it tends to grow in brackish/saline water. It has been collected from tidal mangrove areas where the seawater meets the fresh water. These environments are unsuitable for the other species of Nymphaea that occur in Australia.


Map provided by Dr. Barre Hellquist
For a long time it was believed that it needed to be grown in saline water, that the only way it could be kept alive in pond cultivation was by adding seawater or sea salt. There are rare populations that grow in non-saline water. These have proved to be adaptable to pond culture and are now in cultivation.

N. nouchali has been found growing with N. violacea in two locations -- both non-saline. Sadly one of these locations was filled in by the owner and no longer exists. No natural crosses with other Australian Nymphaea have been recorded.  
The Australian form of N. nouchali is a miniature plant with four sepals and eight petals. It is a classic model of a primitive flower with the petals and sepals showing very little differentiation from bud sheaths. The stamens are smaller versions of the petals. The flower gives a good illustration of how the bud sheaths of plants progressed into flowers. It could be considered as one of the oldest living examples of when flowering plants first evolved from Gymnosperms (cone bearers) into Angiosperms (flowering plants). It might be what the first waterlilies looked like before they evolved into more complex forms.  


Carlos Magdalena, RBG Kew, Photo 

The area of Australia where it is found has the highest number of primitive flowering plants in the world because it has been relatively geologically and climatically stable since the end of the Permian period. It was long after this geological period that the first flowering plants evolved over 100 million years ago. These primitive flowering plants are relics that have survived from that time. Ice ages, climate change, volcanoes, upheavals, droughts, flooding and other events have led to their extinction in most parts of the world.

It might be assumed that, because N. nouchali is the only example of a Brachyceras in Australia, this plant was introduced to Australia. However, it could be that this plant is a surviving relic of the first waterlilies that evolved on the ancient super continent of Gondwana before it split into Africa, Madagascar, South America, India, Australia and parts of Southeast Asia. It may be no accident that it survived in the area of this super continent with the geological and climatic conditions that has enabled the survival of so many primitive flowering species.

The Australian form of N. nouchali is distinctly different from the forms of N. nouchali in cultivation. They are so different in size, flower shape, petal numbers, petal shape, and stamen shape it is difficult to see how they can be called the same species. Morphologically the cultivated, and even "wild", forms of N. nouchali look more like N. capensis. It has been suggested by Dr. John Wiersema of the GRIN Taxonomy Database that the Australian nouchali is the true ancient form and that the others may be hybrids.

Looking at pictures of what is claimed to be N. nouchali, they look like hybrids and they come in every colour apart from yellow. Some look like 'Director George T. Moore' in different colours. It is likely that many of the plants that grow in Asia are of hybrid origin.  


The Australian form of N. nouchali is more closely related to N. minuta than to the forms of nouchali that are currently in cultivation. The similarities are:

Both are tiny.
Flower shape, sepals, stamens and petal count seem to be the same.
They both flower sparsely, one or two blooms every now and then.
Both shed pollen the first day and are cleistogamous.
Flower petioles curl and sink to the very bottom.

However there are enough difference to justify them being two different species:

The main difference is the seed, which is quite large for a Brachyceras in minuta (elipsoidal) and very small in nouchali (spherical).
Spotted sepals green in colour for nouchali, reddish, no spots for minuta
Very different leaf undersides 

N. minuta - Kit Knotts Photo


N. nouchali
Carlos Magdalena, RBG Kew, Photo

 

 

N. nouchali
Nan Bailey & Carlos Magdalena, RBG Kew, Photos
 

N. minuta
James Knock & Carlos Magdalena, RBG Kew, Photos

     

N. nouchali
Carlos Magdalena, RBG Kew, Photos
 

 N. minuta
James Knock Photos
         
There is a need to compare the original type specimen of N. nouchali and other herbarium specimens with the Australian specimens to see if they are identical. Just as importantly there is a need to look at DNA from herbarium specimens, the Aussie nouchali, native Asian nouchali and cultivated plants of nouchali. This will help clarify what is a very confused taxonomy. However, it is clear that the current forms of cultivated plants named as N. nouchali and the plant of the same name found in Australia are very different and need to be separated taxonomically.   

The Miniature Tropicals
Introduction & Index
Articles by
Ivan Nozaic | Andre Leu | Carlos Magdalena | Walter Pagels

John Wiersema | Barre Hellquist | Nan Bailey | David Curtright
New Miniature Hybrids by
Carlos Magdalena | Rich Sacher

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