Duckweed on the loose?

January 2nd 2018

Most botanists when visiting Assynt tend, predictably, to make for the limestone, hills or coast.  However, for us locals, engaged in the ‘serious’ business of recording, it is the relatively built-up areas that tend to yield the longest lists.  Gardens and ‘waste ground’ can often house species that are found across much of the British Isles, but may be rare up here, and occasionally there are real surprises.

There was one such surprise on 8th October 2017, when Gwen Richards and I were recording the 1km square NC 0822, which stretches west from Inverpark to Baddidarrach.  At the bottom of Inverpark there is an area of no-man’s land where people tend to deposit their garden rubbish, but which abuts onto an unspoilt stretch of saltmarsh and other coastal vegetation.  Slithering down a bank, through a sallow thicket, we came across a pool just above high tide mark completely carpeted with a tiny floating plant which was instantly recognizable as one of the duckweeds Lemna spp.

No species of duckweed had been recorded from the North-west Highlands until 2014, when I happened upon two in a garden pond at Drumbeg (NC1232) belonging to the late Teresa Weinburg, ivy-leaved L. trisulca and fat L. gibba.  I have since found the latter species in other garden ponds at Clachtoll, Kinlochbervie and Rhue near Ullapool.

Duckweeds are not the most charismatic of plants.  Four of the five species now found in the British Isles consist just of rounded floating fronds adhering in small groups, with few distinguishing characters.  However past experience did enable me to identify the Inverpark example as fat duckweed, probably the first time it has been found ‘in the wild’ north of the Central Belt.  It must have escaped, or been accidentally transferred, from someone’s garden pond, and seems to be thriving.

Ian Evans

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Recent Sightings

Kittiwake

c100 adult and 1st-winter birds feeding off Clachtoll (DAH) (24/09)

Tufted Duck

two male birds on Loch Drumbeg (DAH) (22/09)

Merlin

single bird near Stoer Village Hall (DAH) (21/09)

UPDATE on colour-ringed Oystercatcher

we have heard back from the Icelandic Wader Group regarding the colour-ringed Oystercatcher spotted at Bay of Culkein on Tuesday. It was ringed, as an adult, near its nest while it was territory-guarding on 19th May this year; the location was Eskifjorour which is on the east coast of Iceland. We will post a short article on the Field Club's website in the next few days regarding other sightings of colour-ringed birds recorded in Assynt (DAH) (20/09)

Pink-footed Goose

c225, in four skeins, heading east over Culkein Drumbeg (DAH). Oh boy, it's autumn! (20/09)

Wigeon

single male in eclipse plumage Loch Inver (DAH) (20/09)

Manx Shearwater

young bird rescued from a garden at Inchnadamph (Chris Rix/Andy Summers). The bird, which was well off-course, was successfully released at Stoer the next day. (18/09)

Oystercatcher

four birds resting on rocks Bay of Culkein (DAH). One of these birds, an adult, had a combination of coloured rings on its legs. The details have been submitted to the appropriate ringing scheme, which appears to be the International Wader Study Group, and we will report back once we hear from them. (18/09)

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