Blechnum chilense or cordatum. Which is correct?

Horticulturalists and botanists have for some time had conflicting views in regard to the correct name of this commonly cultivated species of Blechnum originating from temperate South America. Botanists call the plant Blechnum cordatum while gardeners insist that the correct name is Blechnum chilense and that B. cordatum is a different, tropical species differing in many ways from the cold-hardy cultivated plants. It is a member of a difficult group that botanists treat in a variety of ways, mostly as a single variable species.

Part of the confusion results from the ambiguous collection details recorded on the type specimen of Lomaria cordata (= B. cordatum). This specimen resembles the plants cultivated as Blechnum chilense. The type locality is given as Perou-Concepcion. However the collector, Joseph Dombey, did not visit this area but did travel from Peru to Concepcion in Chile where he apparently collected the type specimen.

As the type of Lomaria cordata (published 1811) was collected in Chile, where it is the only member of the complex, the correct name under the rules of priority is Blechnum cordatum. The basionym of B. chilense, Lomaria chilensis, was not published until 1824.

I am sure that the complex includes more than a single species, however we will have to wait until detailed molecular, cytological and morphological studies have been carried out before a more complete understanding is achieved.

Meanwhile, irksome as it is to gardeners, it does appear that botanists are correct on this occasion and the name that should be used is Blechnum cordatum.

1. Blechnum cordatum, Cornwall 2013
Usual form found in UK gardens
2. Blechnum cordatum, Belgium 2014
Different form with less undulate pinnae seen in Belgium

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One thought on “Blechnum chilense or cordatum. Which is correct?”

  1. Hello
    Thank you so much for your interesting information on B. cordatum.
    May I ask you: where was the picture in Belgium taken?
    Thank you for your reaction.
    Best regards
    (Mrs.) Sonja Deneve

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