There is a great curiosity within Nature. Even the most familiar of organisms has an unexpected side to it when you probe deeper. In this section we will be looking at plants, rare
and common, that we have come across in our explorations around Ireland. Typically, this information will draw on good photography. If there is not a good image available then
the topic or species can wait, with the sole exception of a very rare species in an inaccessible place — where we may use a less than perfect image to record its presence. BUT, this
happens more often among animals and insects. Plants, after all, normally stay in the one place and often can be relied on to re-appear year after year…
‘Beau’
Slieve League, Co. Donegal
This species is well known in Ireland, sometimes barely surviving, other times occurring in large dispersed
populations as shown here in the Lough Conn/Cullin areas. These plants under good conditions will emerge and
flower within a week in July and may grow tall and endure for up to 2 months if the weather is good. However, in
recent years such weather has been missing with early heavy rains leading to flooding as early as August.
Fertilisation does take place and ovaries have been seen to swell but normally wither as cold wet weather
becomes dominant. This area still has a healthy population though. Vegetative reproduction has been shown and
individual plants persist for at least 4 years.
“Only occasionally are new colonies [of plants] attributed to natural long-
range dispersal, for example, the arrival of an orchid, Spiranthes
romanzoffianum, in the British Isles in the nineteenth century by wind-
borne seed from North America.”
…..
“An even rarer orchid in Britain is Spiranthes romanzoffianum, native to
wet meadows and bogs scattered widely across North America. Its dust
like wind-borne seeds evidently cross the Atlantic only rarely. It appeared
in a few wet meadows and bogs in Ireland in the nineteenth century and
at a few others in Scotland and England since 1900”
Sauer, Jonathan D. Plant Migration: the dynamics of geographic patterning in
seed plant species. (ISDN 0-520-06003-2)
We used to call it ‘our theory’ — that Spiranthes romanzoffiana populations in Ireland were derived from North
America by wind dispersal — as we had become convinced of this by observing germination patterns on the
shores of Lough Allen that seemed to follow shoreline contours.
This is a rare orchid mainly found in the west of Ireland. It is a spectacular species and, though hard to find, easy
to identify. It is quite characteristic and is found always near water and mainly, though not invariably, west facing
lake shores. It is a late flowering orchid and certainly in recent years it seems rarely to set seed. Fertilisation may
occur but it is rare to see this species bearing seed. Also, changing weather patterns have led populations of this
species to be frequently inundated by Summer/Autumn rains.
So where do these plants come from? Several characteristics of the species may provide the answer…
1.
This species is always (in Ireland) found on lake shores, though the original (1810) record
was from a seashore.
2.
It seems more regular and more abundant on west facing shores. i.e on the east or north
east sections of lakes.
3.
It often occurs at the water’s edge or even partly or totally submerged. On lakes with
great variation of long term water levels, such as L. Allen in Leitrim, it may also appear a
long way from the shore.
4.
However striking flows and curves of plant distribution have been seen in Lough Allen,
perhaps representing a former shoreline where the seed was first deposited.
5.
We believe such seeds land on the lake surface and are then blown to the nearest shore,
in some quantities, where they get absorbed into the mud and start their complex life
cycle.
6.
It is said that seed from this species ‘may take up to 5 years to produce a plant’. Orchids
in general form a mycorrhizal association with soil fungi which provide nutrition to the
orchid to develop a large swollen root from which the first above-ground appearance of
the plant may issue as a suddenly appearing shoot which goes on rapidly to produce the
typical large white spiral flower.
7.
These flowers are hardly ever known to release seeds in Ireland.
As we were starting to put our observations together and form a concept (or a story) to reflect the characteristics
of the species investigated here, we were aware of many traditional theories that circulate about the rare plant we
are investigating today and its ‘sudden appearance in Ireland’ two centuries ago! That the roots were carried by
Geese… not likely as the geese mainly fly from Greenland to Ireland and the roots would in all probability be lost.
That they were brought to West Cork initially by human transplantation as the family had North American
connections. There is no record of this and the first specimens were found on the sea shore. That the plants were
always here! Unlikely as they would probably have been observed in either Scotland or Ireland or in western
Europe where they have never been found… As you can imagine it was a considerable relief when, after a deep
search of online literature, Sauer’s wonderful book was discovered and bought. This is a little known source which
seems to coincide perfectly with our own thinking!
Conn/Cullin complex, Mayo, 23 July 2016
Same groups of plants, 9 August 2016
The Lough Allen population
which has been studied for
over 10 years has been very
unpredictable with numbers
varying from 300 - 1. They
vary from year to year and
whereas there may be a
tendency to lose numbers
the species has been able to
re-occupy sites from which it
has been missing for up to 5
years. Lough Allen is a
recreational lake with water
level controlled for navigat-
ional purposes. This has
restricted the shore zone
available for Spiranthes to
c. 1m in height but this can
mean up to 40m horizontally
on flat silty shores. On such
shores when a good
population of this orchid is
present a ‘shoreline pattern’
of emerging plants can be
discerned. i.e. they follow
contours reflecting, we
suspect, the water level at
the time they landed on the
lake and were then washed
ashore with a prevailing SW
wind?
These two images taken 17
days apart shows the same
specimens in good condition
with no sign of withering or
fertilisation. This reflected a
good dry period which
ended shortly afterwards, as
the plants became flooded.
This probably ended any
possibility of seed
production and dispersal.
Proof of any successful seed
dispersal among the resident
Irish community of this
species is scarce or absent.
Source of New stock:
This Mayo site has consistently large stocks. Plants re-emerge for at least 3 years. But, after that, where does new stock come from? These lakes are nearer to America than Lough Allen! Does more seed bearing rain fall here? The distance is marginal in terms of the width of the Atlantic but the rainfall may be a significant factor. We have one stunning piece of evidence…
It seems plausible that the distribution of c. 100 specimens at Lough Cullin in a broad bay facing south west and
all at very close to the same height requires water based seed deposition. The plant is tolerant to a range of
conditions and elsewhere grows happily further away from the present water level. Most specimens recorded at
Lough Cullin seem to be at roughly the same ‘altitude’. This is hard to judge, and there is small local variation, but
when the Autumn floods start many of these specimens were in 10 - 20cms. of water on one particular day.
The pictures above are of one of the finest displays of Irish Lady’s Tresses in the area — taken about 2 weeks
apart. Fertilising insects are not common on Spiranthes and flooding of the plants in flower is common. They do
not seem well adapted to our climate? In these circumstances can they provide seed to populate the next
generation of plants?
This study area has a total of 135 flowering specimens. This is a ‘wet’ lagoon. i.e. most of the area has flowing
water. On either side of this lagoon are older locations where the lake in the past forced an entry during earlier
winter storms? These quickly dry and trees start to grow.
We believe that in the short period while this lagoon has been open seeds have been carried in through the
narrow entrance to the lake. These flow into all the channels and ponds in the lagoon and settle where they land
forming an association with mycorrhizal fungi only emerging several years later to flower. Our evidence for this is
the pattern of distribution at the same height above water and following the course of present or previous drains!
This implies that lakes in the west of Ireland at certain times carry a lot of Spiranthes seeds floating on their
surfaces? This is, nonetheless, more plausible than seeds casually landing on ideal terrain! Where do these seeds
come from…
Might we suggest… America?
S. romanzoffiana does not occur in continental Europe or Asia and apart from Ireland is only found in Scotland.
West of Mayo the next stop is the America. We don’t see how there can be a sufficient stock of plants here in
Ireland — they were never common — to provide abundant seed? However, this species is widespread in America
as Sauer points out. They occur in all the eastern States and in Canada. The nearest population to Ireland would
be in Newfoundland and Labrador, just where the Jet Stream often passes.
The Jet Stream is a strong upper-atmosphere wind now thought to affect our climate very dramatically. If it
moves south we get rain, if it moves north we get warm weather. If you look at maps of the Jet Stream it will
frequently be seen to travel from North American coasts directly to Ireland and Scotland. Scotland seems to be
getting a good stock of these plants in recent years; has the Jet Stream been moving north? There are mechanisms
whereby light seeds can be lifted into the upper atmosphere and if the upper wind is strong they could be in
Ireland in a day and brought to ground in the Summer rains often associated with the Jet Stream.
The site image (Below) shows one of the Habitats for this species
within the Conn/Cullin complex. It is a microsite of about 2.7
hectares with complex erosion and settlement processes at play.
These processes clearly provide an ideal nursery — we have never
seen so many Spiranthes in such a small area. It is exciting and
does bode well for one of Europe’s rarest species. It is an adaptable
species — a curious plant — and as long as some shorelines are left
natural it can cope and survive.
An exploration of wild & interesting places in Ireland and their western European/American flora and fauna…
Jet streams are fast flowing, relatively narrow air
currents found in the atmosphere around 10 kilometers
(a very common altitude for airplanes) above the
surface of the Earth. They are a purely natural physical
phenomenon forming where masses of air at different
temperatures meet. Hence the connection between
global warming and a greater awareness of Jet-streams
and their impact on our weather.
NetWeather.tv provide beautiful animated maps of the
Jet Stream for up to 14 days ahead. (See Map HERE.)
Archival data is harder to find, i.e. what way was the Jet
Stream 5 years ago between Labrador and Ireland? But
current images show common wind-speeds in excess of
200 km/hr. How long does that take to cross the
Atlantic? (19 hrs?)
Iconic image courtesy of
Wikimedia Commons
This collection of photographs show more of the habitat and some other specimens from the site. Image (ABOVE)
attempts to show the character of the place. This was quite a unique habitat and a fascinating place to explore and
understand. At the time the photograph was taken there was a very slight slope to the main lake, as can be seen
by the gently flowing water. However, it seems unlikely that this site was at risk of drying out in the near future.
Indeed it would have become submersed in the rains that followed.
All specimens were GPS’ed. This data can be superimposed on Open Source mapping and does reflect the
observations recorded here. However the records are much too cluttered to reproduce here. We have found that
using a GPS is also a very convenient way to quickly count large numbers of randomly dispersed plant species. We
use it as a routine nowadays. Also, with care and time, accuracies of close to 2 meters can be obtained — which is
truly amazing!
The remaining 4 images show the variety of habitat from bare to lush vegetation and the variety of specimens we
encountered from stunted to splendid, though none as splendid as the group at the top from a mature colony.
Saxifrages
Saxifragaceae
The nice thing about Saxifrages is that they grow in nice places. The tough thing about them is that they are variable and inter-breed and some are hard to identify. We have raided the archive again and most of these pictures come from the Sligo uplands with two species that grow at lower levels. Pride of place in the Saxifrages must go to the elegant simple and stalwart Alpine Saxifrage (Saxifraga nivalis) shown LEFT. This is a rare plant in Scotland and very rare plant in Ireland. It is found solely in the highest mountains in most circumpolar countries, Ireland being the most southerly. The National Botanic Gardens (Glasnevin) have studied its distribution; this species seems to occur here as ‘an ancient refuge of arctic plants?’ [MORE…] These photographs were taken in June and the stem goes on to be 10 - 12 cm high with up to a dozen large white flowers with two bright red styles (starting to emerge in picture on Left) which are fertilised by other plants.
The beautiful Yellow Saxifrage (Saxifraga
aizoides) This one was photographed on a
limestone pinnacle in north Leitrim
This is Mossy Saxifrage (Saxifraga
hypnoides) with elongated linear leaves
many with 3-pointed as they mature.
The 5 petaled blooms are big and
intensely white yellow centres and
bright yellow pollen.
Rue-leaved Saxifrage (Saxifraga tridactylites).
Recent photo (April 2017) as this hardy annual
starts to appear scattered over an abandoned
quarry. This is one of two low altitude
saxifrages listed here. Common, sticky and
reddish with 3-lobed leaves.
The very modest and another low level altitude is the
carpet forming creeping perennial of wet broadleaved
forest floors — the Golden Saxifrage (Chyrsoplenium
oppositifolium).
This is an intriguing plant being almost missed in the early
Spring broadleaved forest where it forms a widespread
mat under many types of woodland, often only being
replaced as Bluebells and Wild Garlic take over.
Its success in rapidly covering a forest floor must be
something to do with it being a perennial plant and the
speed with which secondary flowering stems develop from
earlier flowers. (More details later…)
THAT’S ABOUT IT for the moment. Undoubtedly we will be
updating this page or adding further articles as 2017’s field
work gathers pace.
WildWest.ie
BACK to TOP
- Caryophyllaceae -
Fringed Sandwort
(Right)
Arenaria ciliata
Not a Saxifrage but, like the Alpine Saxifrage (Above), possibly an Ice Age survivor. A plant with stunning association to this part of the world as can be seen from an interesting article The Gorey Guardian published in 2012 [MORE]. It claims that this is another species that may have survived glaciation on a Sligo upland near the Atlantic that remained exposed during the Ice Age 20,000 years ago. This photograph was taken 8 years ago… a mere minute in the history of this species. An amazing story — do have a read of it — but this is also a very beautiful plant, as are all these arctic survivors. It is a member of the Pink family with larger more perfect flowers than the saxifrages. It is also of the same family as the Moss Campion (see below) which is also a specialty of these mountains. Apparently DNA testing indicates that these species have been present in this location in the Darty Mountains for up to 150,000 years!
Moss Campion
(Below)
Silene acaulis
Another handsome member of the Pink family, this very attractive high mountain Campion is found only in NW Ireland and Scottish Highlands. The flowers are quite delicate and appear from a cushion of fine pointed leaves. Can be a plant of very high mountains but seems to thrive at a lower level near the sea as in Sligo.
A: Trans-Atlantic Plant migration…
B: Saxifrages and other Alpine plants…
Curious PlantsB: Saxifrages et al
A particularly healthy vegetatively reproducing group of Spiranthes — why don’t
they set seed!
We have withdrawn Map formerly published here for
copyright reasons and for updating. BUT our evidence has
been strengthened and, as of Autumn 2017, we feel we have
Proof of Spiranthes Migration across the Atlantic…
www.WildWest.ie/spiranthesmigration.html
For an update on our S. romanzoffiana research please read our
2017 Report on this topic, HERE