landgirl's picture

Fern

Observed: 2nd July 2013 By: landgirllandgirl’s reputation in Plantslandgirl’s reputation in Plantslandgirl’s reputation in Plantslandgirl’s reputation in Plantslandgirl’s reputation in Plants
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Description:

Growing on brickwork of railway embankment.

Identifications
Species interactions

No interactions present.

Comments

landgirl's picture

Stems

Chris, do the stalks darken later in the season?

lavateraguy's picture

Stace says that ...

... the petioles (not rachises) are reddish-brown to blackish. But looking at my photographs of this, they have green petioles, as do many (but not all) photographs online.

Chris Metherell's picture

Asplenium adiantum-nigrum

Technically the stem below the frond is called a stipe in ferns - not that it matters. Most descriptions refer to the stipe in this species as being red-brown or nearly black. But as has been noted, many seem to have this character missing. Often the stipe is only dark at the very base and it's necessary to dig about in the centre of the fronds to see what's happening. I don't know, I'm afraid whether the stipes darken with age. Quite possible. This species is extremely variable however and perhaps the lack of darkening is typical of some populations. Sounds like some research might be undertaken....

Chris Metherell
BSBI VC Recorder
North Northumberland

landgirl's picture

Thanks

I'll look for this next time I see this fern.