Plants of Skye, Raasay & The Small Isles

The talk seemed to go down well and the audience was surprisingly numerous. Local ceramicist Patricia Shone was able to tell me that the Cephalanthera longifolia (Narrow-leaved Helleborine) at Fairy Glen, Calligarry was still present in 2011. This is something I have looked for and in the absence of a precise location, failed to find. The distribution map now looks like this:

Cephalanthera longifolia

The remaining red dot is for a 1977 record at Armadale Castle. (Corrected from earlier version of this post.)

From Sandy Masson I learned that the Peltaria alliacea (Garlic Cress) at the top of the shore at Rubha Phòile was planted by an itinerant Irishman in, I think, 1988, and that it seeds up onto the area above.

Roger was inspired to send me further Aspen and Early-purple Orchid records today – but we still have no EPO record for Sleat since before the year 2000.

There seemed to be some enthusiasm to look out for plants not recorded recently in Sleat.  I am, of course, always delighted to receive records or queries – or images for identification…..

Elsewhere, members of the Skye Botany Group are stirring, and apparently concentrating on aliens. Linda reports Cortaderia richardii (Early Pampas-grass) from a new 10km square near Greshornish  so that the distribution map now looks like this:

Cortaderia richardii

Watch out – this pest may be heading your way…..

Meanwhile Steve reports Cotoneaster simonsii (Himalayan Cotoneaster) from NG52, the first record for that 10km square for forty years.

By myself Wednesday 26th February Ardvasar Village Hall 19:30.

I have found yet another reference to aspen as being scarce on Skye. It isn’t. It is a common plant here:

Aspen Distribution Map

Jim Bevan has sent me his database containing over 10,000 records, nearly all from the Small Isles and before the year 2000. Nearly 6000 of these are records he was involved with during the 1990s, either alone or more commonly with others.  What makes them so valuable is that  they are mostly at tetrad or better resolution – making a huge difference to the appearance of the history of recording in the Small Isles as shown below for Potentilla erecta (Tormentil).

Records ex-Bevan

Records pre-Bevan

When I combine the two sets of data there will be a lot of red dots behind the black ones.

Many of the remaining records in the database are from other published or unpublished sources and in many cases I already have them in some form.  However, I am importing nearly all of them as in many cases there is more detail than I previously possessed. For example, a number of records I received from the BSBI Distributional Database for Hyskeir were anonymous and with a wide date range of 1987 to 1999. I now know them to have been made by D. Miller on 7/6/1992 and 30/4/1993.

Jim’s database contains records for 136 taxa that are included in the Rare Plants Register. In general these records are not going to significantly affect the distribution of plants recorded in the RPR, but it is now going to be much bigger task to update it than I had been planning.  This may wait for next winter now.

Andy Amphlett has very kindly produced a map of vice-county 104 showing land above 300m, native woodland, other woodland, lochs, and A and B roads which I have imported into MapMate and can now use as a background to my distribution maps:

I think this works rather well…..

Terry has been monitoring orchids on his Skye croft for some time and managing the land for their benefit. Orchid numbers have increased considerably and over the past six years he has been measuring and counting assiduously. He has sent me his results re Greater and Lesser butterfly-orchids and, to summarise a lot of material rather briefly, the data that he has gathered show the following statistically significant differences:

a) Lesser Butterfly-orchids (Platanthera bifolia) flower 7 – 9 days earlier than Greater Butterfly-orchids (P. chlorantha).

b) Height of the flower spike: Lesser average 17.2 cm, Greater average 25.3 cm

c) Width of the lower of the 2 basal leaves: Lesser average 2.4 cm, Greater average 3.2 cm

d) Spur length: Lesser average 1.6 cm, Greater average 2.5 cm

So overall, Greater Butterfly-orchids are more robust than Lesser Butterfly-orchids, a finding that is not always recognised in the literature, though is perhaps implicit in the vernacular names.

It remains a mystery as to whether they different species or as the molecular evidence purports, an example of morphological polymorphism.

Terry says “Morphology would suggest they are [different species], and my data shows that there are differences in the physical size of the two orchids as well as the pollinia positioning differences.   But I am not so sure, and it may be that one is just a bigger version of the other, adapting to different habitat conditions.”

Excellent stuff and the work continues. He also gets some fine hybrid orchids.  Much of the above is taken directly from Terrys’s notes – many thanks for sharing!

P. bifolia       Photo T Swainbank

P. chlorantha     Photo: T. Swainbank