Earlier this week I wrote about plants at the National Botanic Gardens of Ireland which would be pollinated by beetles, geckos and lemurs in their natural habitats. There were too many fun facts to fit into one post! Here are a few more plants which deserved a special mention…
Many of the orchids in the palm house were in bloom when my Dad and I visited at the end of February. Each one is perfectly evolved for pollinator-specific relationships. They have landing platforms for bees, pungent odours to attract flies, or they imitate insects like our own native bee orchid.
This is where the National Botanic Gardens boasts another pollination wonder from Madagascar – Angraecum sesquipedale. In 1862, Darwin theorised that this long-nectaried orchid could only be pollinated by a moth with an equally long proboscis, which would have co-evolved with the plant. In 1907, more than 20 years after Darwin passed away, that very moth (Xanthopan morganii praedicta) was found in Madagascar.
Finally, we were treated to some real pollination in action. We spotted a queen Bombus terrestris/lucorum fuelling up on the flowers of a Pieris sp.
Queen bees emerge early to begin searching for nest sites in places such as the lovely untidy, tussocky bases of hedgerows. Early flowering plants are essential to their survival, so let those dandelions and other “weeds” bloom! Don’t mow, let it grow!
My dad and I were late season visitors to the National Botanic Gardens of Ireland’s Hidden February Blossoms tour at the very end of last month. Despite our tardiness, the tour guide diligently sought out each and every plant species that was still in flower, and had something equally fascinating to say about every non-blooming thing in between.
As someone who gets a kick out of plant-animal interactions, all my favourite facts were about pollination. Did you know that Magnolia is such an ancient plant it predates the evolution of bees, and is pollinated by a wide range of beetle species instead? Pollination researcher Beatriz Moisset describes the relationship perfectly:
“Beetles are very clumsy at their task; sometimes they get carried away and eat parts of the flowers along with the pollen they find there. Their mouth parts are made for chewing…so they can’t be blamed for their sloppiness. The flowers, in turn, are adapted to this rough treatment…”
The excitement on my face following this revelation ensured that the subject matter of our tour veered towards pollination as much as towards the original theme of winter flowers!
Moving along into the curvilinear range, designed by Robert Turner and constructed in a mere quarter of a century, we were introduced to the rare Nesocodon mauritianus. Its blue, bell-shaped flowers drip with nectar as orange as cough-syrup. The pollination of this species remained a mystery until 2006 when researchers discovered that two other plants with coloured nectar on its island home of Mauritius were pollinated by Phelsuma day geckos. Hansen, Beer and Müller (2006) demonstrated that Phelsuma ornata geckos prefer coloured nectar to clear nectar (which most other flowers contain).
“In flowering plants, coloured nectar could additionally function as an honest signal that allows pollinators to assert the presence and judge the size of a reward prior to flower visitation, and to adjust their behaviour accordingly, leading to increased pollinator efficiency.”
In other words, coloured nectar allows the geckos to spot and choose their lunch and tells them where to pay. But not all geckos are such honest nectar customers. Here is a paper featuring stunning shots of a Phelsuma stealing nectar from mangrove flowers in Madagascar, bypassing the pollen entirely! Unlike Nesocodon mauritianus, the mangrove Sonneratia alba has white flowers which bloom at night so it can also attract the more helpful bats and moths.
I can’t mention day geckos without showing you a photo of Phelsuma antanosy, a species I was researching with SEED Madagascar. I have observed them licking clear nectar from small flowers. I wonder how useful they were being in terms of pollen transportation!
After paying homage to the rhododendrons, azalias, andromedas and witch hazel, all brightening up wintry grey Ireland with their dazzling colours, we entered the palm house. And there stood the plant which takes me back to Madagascar most nostalgically of all. The Traveller’s Palm.
Cue the compulsory discussion about the origin of its common name: Stab it and out flows water to quench your thirst on a long journey. It might be stagnant and full of bugs, but as a last resort it could probably save you from death by dehydration. You can also use its leaves as an umbrella or a parasol, or for covering food on the long journey from the mountains to the market. The leaves grow east to west so you can use them like a compass. Or is it north to south? Or do they actually at all? Because I’ve seen them do both, so maybe I’ve misunderstood something, but I would not like to count on it if I was lost in the bush. This is where the facts always start to become a bit alternative. Can anyone shed light on this mystery?
Our guide then revealed the pollinators of the Traveller’s Palm: lemurs! The plant co-evolved with ruffed lemurs, whose fluffy faces make the perfect pollen brush! How I lived in Madagascar for 16 months without learning this is a mystery. Too busy with my nose in the undergrowth looking for insects and frogs, perhaps!