11 June 2013

Orchid confusion in Northumberland: 7 June

This week I've learned that Dactylorhiza orchids are 'fracking' hard to ID! And I'm not talking Reed/Marsh Warbler hard here, more like Alder/Willow Flycatcher hard! Not only do Dactylorhiza species look incredibly similar, but there is a huge amount of variation within species and hybridisation is very common. Even Kew struggle to put a name to them (see here), so as a notice botanist what chance do I have?

At Lindisfarne on Sunday we found quite a few orchids growing in the sand dunes at The Snook and in the dunes along the north shore of the main island. I identified several as Northern Marsh-orchid Dactylorhiza purpurella but noted a large variation in flower colour and shape. But after a little online reading I started to doubt my identification, so back on Lindisfarne this morning I took a closer look at them.

Dactylorhiza orchids, The Snook, Lindisfarne. Note the variation in size, shape and flower colour.

I think both the pale pink and darker purple orchids we found here are Northern Marsh-orchid Dactylorhiza purpurella. Both have similar shaped flowers with a similar pattern of deeper purple lines and spots on the lip (lower petal) and a whitish throat, as well as unspotted leaves (although apparently some purpurella can have dark spots on the leaves too).

Northern Marsh-orchid Dactylorhiza purpurella, The Snook, Lindisfarne

Northern Marsh-orchid Dactylorhiza purpurella, The Snook, Lindisfarne

Note the similarity in the flower shape and pattern of deeper purple lines and spots in this pic and the pic below

Maybe the flowers become lighter as they age?

Animalia were easier to name but thin on the ground at Lindisfarne today. Lepidoptera were keeping their heads down in the cool easterly wind, with just a single Wall Lasiommata megera butterfly and a few The Cinnabar Tyria jacobaeae moths seen, and still no sign of any Dark Green Fritillaries. 3 Common Swift over north and several Ringed Plover, 5 Dunlin and a few Common Eider were picked out on the estuary were the only birds of note.

Wall Lasiommata megera, The Snook, Lindisfarne. These butterflies have declined severely over the last several decades and are
now found mainly in coastal areas. Northumberland lies at the northern edge of their range.

The Cinnabar Tyria jacobaeae, The Snook, Lindisfarne

A quiet hour or so this afternoon at Newton Pool logged 1m Yellow Wagtail, 2m Common Teal, 4 Ringed Plover, several Pied Wagtail, 1 ad. Kittiwake, 4+ Sand Martin, 1 Sedge Warbler, 1 juv Stonechat, a juv Robin being fed by an adult and a couple of Willow Warbler (H). No sign of yesterday's Barnacle Goose though.

Today was our last day in Northumberland and we're really sad to leave. Northumberland is teaming with wildlife and we've had a great week taking in the seabird spectacle and wild flowers. We're really looking forward to coming back - maybe in the autumn for some east coast migration?

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