In the first installment of this story of a small population
of Nymphaea lotus growing in Eastern European hot springs,
I asked whether the population is substantially distinct from
N. lotus elsewhere. Results are in.
Molecular data (nrITS-sequencing) obtained by Dr. Gábor
Sramkó showed no distinction between samples of N.
lotus collected by Mr. Lukács from Petea, Romania,
and the Nile Delta, and others received from South Africa. This
is still work in progress. A summary by Gábor Sramkó
of the early results gives a taste of the start:
The nrITS sequences of two plants from each of the three
geographic regions were 676 bp long, and they could be aligned
unambiguously. Additionally, no indication of intra-individual
sequence paralogy in this biparentally inherited marker was observed,
which could have undermined the direct comparison of nrITS sequences.
The direct comparison of the aligned matrix showed the sequences
were identical, so this DNA region does not separate the accessions
from the three locations.
This information alone would only allow us to draw limited
inferences about this similarity. But if we regard the fact that
nrITS exhibits one of the highest known substitution rates among
plants [II] and we also take the results of Löhne et all
[III] into consideration (as extrapolated from their molecular
clock calibrated phylogram in Fig. 5., the isolation of Nymphaea
petersiana from the N. pubescens N. lotus sister
species can be dated back to approximately 5.1 Mya), we can conclude
that the absence of differences in this fast evolving marker
serves as hard evidence that the Oradea plant was not isolated
from the rest of the populations long ago. Certainly not as long
as the onset of the Quaternary era (approximately 2.5 Mya), when
the glaciations swept through the subtropical vegetation of the
Central European region.
Moreover, if we compare our sequences to the nrITS sequence
of N. pubescens retrieved from GenBank, we find notable
dissimilarity in terms of sequence divergence (31 point mutations
separate N. pubescens (FJ198406) from our samples). Thus,
if so many mutations have accumulated after the isolation of
N. pubescens from N. lotus, the lack of difference
between N. lotus samples might be indicative of recent
intra-specific isolation and/or recent expansion of the species.
So, this preliminary result of molecular phylogenetic study suggests
the relatively recent introduction of Nymphaea lotus population
into the thermal springs of Oradea.
In order to test the scenario, albeit unlikely, that
introduction [I] was recent by migratory animals during the Holocene
or human introduction in historical times, more samples of N.
lotus would need to be analyzed with high resolution molecular
It must be said that the familiar appearance of the plants
and the track record of pre-war academic debate -- alternatively
proposing and doubting their identity as a distinct variety of
N. lotus, is accommodating the present result all too
The small size and isolation of the population may have had
slowed its changes over time, at least while such conditions
persisted given climate and geologic conditions. While
it may be easy to prove that this has been isolated there for
many years, writes Carlos Magdalena, it may be impossible
to disprove it. What about this plant propagating itself clonally
]? Low variability in a population that is isolated and
has no external pressures may lead to not a great deal of change?
Such questions are about to be addressed, and the results
will add to the interest of the small ecosystem and its floating
showpiece. On the side, there is the story of how science was
made and minted around these plants, and thats bound to
be worth telling these days. Overall, tropical waterlily pads
amid winter snow make their own stories on sight. And where there
is curiosity, questions tend to come out
It may be worth mentioning at this point that one taxonomic
revision is not necessarily big news. Although getting names
right might appear as an essential foundation of just about any
further work, the task of getting ALL names right is anything
but [IV] and its assignment provides a fair share of interesting
twists to the history of science. Only a few large scale studies
find practical need for such a broad perspective [III], and even
those may not feel the sting of slight imperfections in the big
picture such as this case of taxonomic uncertainty. Unless they
If what does happen to an isolated, self-sustaining population
of a few thousand N. lotus has any significance, there
is still work to be done around Petea lake.
Certainly, the possibility remains that Petea is holding not
the last N. lotus to have cheated its way out of the last
European Ice Age, but the oldest water garden around those parts.
Even as the unintended consequence of some ambitious gardening
cca. 1740 [V], the place beckons. What is a good recipe to make
a water garden keep itself interesting for two hundred years?
[I] Geologic dating suggests an age of the
geologic formation supporting the lotus population of less then
twenty thousand years. Sources cited in the first installment
of this story: Water Gardeners
International, Vol.3, No.4, November 2008.
[II] Calonje M, Martín-Bravo S, Dobe
C, Gong W, Jordon-Thaden I, Kiefer C, Kiefer M, Paule J, Schmickl
R, Koch MA (2009) Non-coding nuclear DNA markers in phylogenetic
reconstruction. Plant Systematics and Evolution 282: 257280.
[III] Löhne, C., Yoo, M.-J., Borsch,
T., Wiersema, J. H., Wilde, V., Bell, C. D., Barthlott, W., Soltis,
D. E. & Soltis, P. S. (2008): Biogeography of Nymphaeales:
Extant patterns and historical events. Taxon 57 (4): 1123-1146.
[IV] For an example of how and where this
argument is made, see:
C. Löhne & W. Berendsohn, Priorities for the development
of a European taxonomic information system, a presentation
delivered to the EPBRS forum [European Platform for Biodiversity
Research Strategy], Pruhonice 19-22 May 2009. [http://www.epbrs.org/PDF/Löhne_Berendsohn.pdf]
And one example of how taxonomy gets occasionally
Löhne, C., Wiersema, J. H. & Borsch, T. (2009): The
unusual Ondinea, actually just another Australian water-lily
of Nymphaea subg. Anecphya (Nymphaeaceae).
Willdenowia 39(1): 55-58.
[V] Some cases of ornamental plants spread into the wild from
initial use as garden plants are known the Roman garden
roses and some types of Middle-Eastern crocus are such examples.
To date, I am not aware of any such story for an ornamental water
plant in Europe. The use of N. lotus as such when the
population near Oradea has been documented, first, remains to
be clarified. Records of the local administration predate this,
but have not been searched for this article.
[VI] Citing an e-mail comment to the article.