Mibora minima (Early Sand-grass) on North Bull Island, Dublin – second record for Ireland MELINDA LYONS
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n the course of ecological fieldwork on behalf of Dublin City Council, I found Mibora minima (Early Sand-grass), a tiny annual grass of sandy coastal habitats, growing on sand dunes on North Bull Island, Dublin Bay (v.c. H21), on 3 April 2019. Prior to this find, it was known from only one location in Ireland, the Cannawee dune system at Barley Cove, West Cork (O’Mahony, 2006). Species nomenclature throughout this account is in accordance with Stace (2019) for vascular plants and Hill et al. (2008) for bryophytes. Despite its small stature, flowering plants of M. minima are distinctive in appearance, with racemes of reddish spikelets set against narrow, bright green leaves (Plate 1). On North Bull Island, they occur in sparse, low-growing vegetation along the edges of sandy tracks through the dunes, often amongst mats of the moss Syntrichia ruralis var. ruraliformis (Plate 2), and sometimes extending beyond the moss mat onto otherwise bare sand (Plate 1). The most frequent accompanying species are Valerianella locusta var. dunensis (Cornsalad), Arenaria serpyllifolia (Thymeleaved Sandwort), Erophila verna (Whitlowgrass),
Plate 1. Tiny flowering plants of Mibora minima, just a few centimetres tall, in partially stabilised sand on North Bull Island, Dublin Bay, February 2020. Photographs by the author.
Festuca rubra (Red Fescue), Brachythecium albicans and Bryum capillare, along with occasional Aira praecox (Early Hair-grass), Anthyllis vulneraria (Kidney Vetch), Cerastium diffusum (Sea Mouse-ear), C. semidecandrum (Little Mouse-ear), Galium verum (Lady’s Bedstraw), Hypochaeris radicata (Cat’s-ear), Leontodon saxatilis (Lesser Hawkbit), Myosotis ramosissima (Early Forgetme-not), Taraxacum officinale agg. (Dandelion), Trifolium arvense (Hare’s-foot Clover), Veronica arvensis (Wall Speedwell), Viola tricolor (Wild Pansy), Ceratodon purpureus, Didymodon fallax, Homalothecium lutescens and Peltigera didactyla. Vicia lathyroides (Spring Vetch), Viola canina (Heath Dog-violet) and Phleum arenarium (Sand Cat’s-tail) are present in small amounts. This assemblage belongs to the Tortulo-Phleetum ephemeral sand dune community (Moore, 1977). This low-growing vegetation forms a narrow band between the exposed sand on tracks and the taller, Marram-dominated vegetation of the dunes (Plate 3). BSBI NEWS 146 | January 2021
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