Wednesday, 24 July 2019

Cicerbita at Clapham

Friday was the last day of the BSBI Summer Meeting and the rain finally returned. On route home I thought I would stop in Clapham to check out a Pirri-pirri-bur (Acaena) record that need a second look. Perhaps more on that later.

I had not visited Clapham in summer before, so I thought it a good opportunity to poke around the village for other plants of interest. Of course the Common Blue-sowthistle was in full bloom, so an easy tick for Cicerbita macrophylla subsp. uralensis. After all, all the Floras will tell you that this is our plant.

Cicerbia macrophylla subsp. uralensis

A little further on I found a new stand, but it didn't sit right. Huge plants towering over my head, stupidly large terminal lobes on the basal leaves and altogether too robust. It was also very glandular in the inflorescence which I did not remember noticing before in this species. So back again I went to the first stand for a second look, and yes half the height, more flimsy, smaller foliage and scarcely hairy in the inflorescence. Quite a different jizz. So what was it?

I was expecting one of the other naturalised species, but the leaves were wrong. So next stop with an alien is to visit the excellent Alien Plants of Belgium website, and lucky for me I was straight to an answer. Cicerbita macrophylla subsp. macrophylla. Key below.

  • Terminal lobe of basal leaves up to 40 cm long. Lowermost inflorescence branches 2-3,5 mm wide at base. Glandular hairs in inflorescence very dense, unequal in length (0,5-2 mm long). Stem up to 300(-350) cm tall === subsp. macrophylla
  • Terminal lobe of basal leaves up to 25 cm long (often less). Lowermost inflorescence branches 1-2(-2,5) mm wide at base. Glandular hairs in inflorescence often less dense, subequal in length (ca. 1 mm long). Stem up to 200 cm tall === subsp. uralensis

This seems to be the first record for Britain. Is it likely to prove more widespread? Perhaps. It is probably no coincidence that it is naturalised in Clapham, given it was the home of legendary plant hunter and collector Reginald Farrer. Still, one to look out for elsewhere regardless of received wisdom.

Cicerbita macrophylla subsp. macrophylla

Friday, 19 July 2019

New for Yorkshire

Just back from an enjoyable week at Malham for the BSBI Summer Meeting. More on this to follow soon, but also see the daily accounts on the main BSBI blog.

The first good find of the week didn't take very long. With a little time to kill on the first day, while I waited for everyone else to arrive, I had a stroll round the grounds of Malham Tarn House. Examining the rock cutting by the driveway I found what looked a very odd Caucasian-stonecrop (Sedum spurium - conscious use of the old name here as the database is yet to catch up with Stace 4). The plant looked far too delicate, and the leaves a little too petiolate. So into the pocket it went to look at later.

It didn't take too much effort later to get it to Lesser Caucasian-stonecrop (Sedum stolonifera). The obscurely* papillose leaf margins providing the final confirmation. A first for VC64 and Yorkshire. Surely a species to actively search for elsewhere, as it is probably overlooked.

*correction from original post, stolonifera is obscurely papillose i.e. small raised bumps. In comparison spurium is obviously papillose with long papillae (longer than wide). You can feel them with your finger towards the tip of the leaf.