Isle of Wight records of Hard Shield Fern (Polystichum aculeatum)

Dr Bromfield (1856), in ‘Flora Vectensis’ recorded Hard Shield Fern, (now P. aculeatum) as P. lobatum :-

“On hedgebanks, in moist woods, &c.; very rare with us.

East Medina – A single root on a bank of a lane close to Cooper’s, near Bembridge, Dr Bell-Salter, 1841-42!!!

Bank on the left-hand side of the road going from the lodge at E. Cowes castle towards Whippingham, Miss G. Kilderbee!

Bromfield’s description of Hard Shield Fern matches our present concept of the species and he confirms that he has seen (!) the plants concerned. He was familiar with it through a correspondent, who probably sent samples, rather than by personal experience in the field.

Bromfield left the Island in 1850 and died in the following year. Bell Salter and Hooker edited and published his manuscript of Flora Vectensis and it is dated May 1856. They added more records from the interval, mostly those of Bell Salter who was a resident on the Island. An editorial comment, presumably by Hooker, says Bell Salter “considers…(the Whippingham record)…to be the lonchitidiform var. of A. angulare” but goes on to disagree convincingly by reference to a “non-fruiting” specimen from Miss Kilderbee which is said to uphold the identification.

From Bevis et al., (1978) the Flora of the Isle of Wight, we learn the identity of Bell Salter’s sample. On enquiry of Kew Herbarium, the response was elicited “The single frond is clearly referable to Polystichum setiferum (Forsk.) Woynar, and not to P. aculeatum (L.) Roth.”, which is to say it was Soft rather than Hard Shield Fern.

All this suggests that Bell Salter was not clear about the division of the two species, though his colleagues were in concurrence. Miss Kilderbee’s sample, he says, is a variety of Soft Shield Fern (P. setiferum), which indeed is what his own turns out to be. We have proof that Bell Salter’s record ID was mistaken but we also know that his plant differed from that of Miss Kilderbee and that Hooker believed her plant to be P. aculeatum.

As a record from the editors there is one further record, “[In the lane and copse by Little Smallbrook, a few plants only, A.G.More, Esq., Edrs.]”. At the time (1852-6) Alexander More was in his early twenties and a protégé of Bell Salter’s and this will have been one of his early records.

Bill Shepard, one of the authors of the Flora of the Isle of Wight (1978), published in 1983 a list of records new since the publication of the Flora in which he reports –
Polystichum aculeatum (L) Roth. Hard Shield-fern
In the Flora it was stated that the species was unacceptable owing to lack of supporting evidence. In the meantime the existence of two herbarium sheets has been communicated to me:

‘Herb. Brit. Mus. P. “aculeatum” Roth. Ex. Herb. F. J. Hanbury. no. 1383. Hedge near church at Westover, Isle of Wight. 15.8.1871.’, and from the Druce Herbarium at Oxford, ‘hedge opposite the Sun Inn at Calbourne, Isle of Wight. Fred Stratton. 15th August, 1871.’

As the dates of both sheets correspond it is reasonable to suppose that the botanists were together and that only the one plant existed. A section of the hedge in front of the Sun Inn has been removed to give greater visibility at the crossroads.”,

a conclusion which is clearly very likely.

Miss Kilderbee was an excellent field botanist, with a knack for finding new sites and plants. None of her samples of Hard Shield Fern seem to have survived in herbaria but, taken with Bromfield’s and Hooker’s agreement on its identity, it seems likely that hers was the first actual record of the fern on the Island.

A man of exact mind; it is surprising that More should have left his record uncorrected if he subsequently doubted the identification and this might also have been Hard Shield Fern.