Field Trip Reports 2010Field_Trip_Reports.html

Birdsfoot Trefoil (Lotus corniculatus)

Lesser Trefoil (Trifolium dubium)

Saturday 22nd May - Mornington Dunes, Drogheda 


Declan Doogue


Members of the Dublin and Belfast Naturalists’ Field Clubs reassembled from various directions at the mouth of the Boyne for an afternoon of sunny botany led by Declan Doogue of DNFC.


Declan showed us 2 precious books - a 1726 edition of Caleb Threlkeld’s Flora and a facsimile of another edition (see opposite)– both mentioned finds of Sea-rocket (Cakile maritima) and the parasite Dodder (Cuscuta epithymum), used “to purge melancholy” , being found at the Maiden Tower, a reputedly Elizabethan light-house, where we had met.  We saw neither of these plants but we did see many others and learnt a great deal from Declan about the nature of sand dunes, appropriately on World Bio-diversity Day.

We watched Little Terns diving into the estuary from their nest site on the northern shore. Declan explained that sea walls had been built along the estuary to improve navigation and, as at Bull Island in Dublin Bay, dunes and sea marshes had formed.  These dunes were on ridges of gravel so did not have moist slacks.   Sand Sedge (Carex arenaria) with its far-creeping  rooting stems helped to anchor the sand. Plants of the Pea family fixed nitrogen in the sandy soil and we identified 6 in one small area – beautiful swathes of Birdsfoot Trefoil (Lotus corniculatus), Lesser Trefoil (Trifolium dubium), worn as Shamrock, “Common” Vetch (Vicia sativa ssp angustifolia), Kidney Vetch (Anthyllis vulneraria)  and the more familiar Red and White Clovers (Trifolium pratense and repens).


A diversion was made to investigate a tall plant at the edge of the dune area – it was a Hellebore in seed, presumably a garden escape.  

A plant new to many northerners was Field Mouse-ear (Cerastium arvense) similar to Snow-in-summer (Cerastium tomentosum).

On other parts of the dune area we found Weld (Reseda luteola), maritime Wild Pansy (Viola tricolor ssp.curtisii), Common Milkwort (Polygala vulgaris) and Bulbous Buttercup (Ranunculus bulbosus) with its turned-down sepals as well as 2 other members of the Pea family – Black Medick (Medicago lupulina) and  Rest-harrow (Ononis repens) which “arrests harrows” with its woody tough stems. The photographers were busy when we were shewn 2  beautiful  small grasses -Sand Catstail (Phleum arenarium) and Crested Hair-grass (Koeleria cristata).


On the shore Lyme Grass, brought in to stabilise sand, was becoming dominant and creating steps up from the shore.  Decaying seaweed provided nutrients on the shore so that Oraches (Atriplices) and Sea  Sandwort (Honkenya peploides) could become established. So valuable had seaweed been that in the past there were seaweed wars at Rush and Malahide.


We made our way back past human bodies being toasted in the hot sun while listening to the deafening noise of car radios to make a brief visit to the unspoilt tidal mud flats and salt marsh.




Declan was thanked for giving us a most informative and entertaining afternoon and we said good- bye to the Dubliners after a pleasant day beside the Boyne.      Margaret Marshall

 

Field Mouse-ear (Cerastium arvense)

Lyme Grass

Ranunculus bulbosus

Wild Pansy (Viola tricolor ssp.curtisii)

©All images on this website are copyright

Home        Events        Programme        Membership        History        Contact        Field Trip Reports        Links     Archive