Advent Botany at Bix

Large shuttlecocks of Dryopteris affinis growing toward the bottom of a wooded valley on the Nettlebed Estate

Atlas 2020 recording stops for nothing! The first weekend of December saw local botanists taking up their clipboards and setting out into the mist to record vascular plants around Bix (SU78H) in the Chilterns. There wasn't exactly a throng of us, just myself and an extremely keen companion, but we covered a lot of ground, getting together a list of over 220 taxa. Winter can be surprisingly rewarding if you've never looked for plants outside of what is usually considered 'the season' — one just has to be prepared to identify things vegetatively and from dead stuff ('dead-getatively' I call it). Some of the plants usually considered vernal species, such as Erophila verna (common whitlowgrass) or Ficaria verna (lesser celandine) actually start to reappear in autumn and early winter if you know what to look for (the forked hairs on the tiny leaf rosettes of the former are quite lovely!), so you needn't wait until spring!

The Bix area is similar to much of the rest of the Oxfordshire Chilterns, in that woodlands figure prominently and it is under-recorded. One of the things I find interesting in the Chilterns is the mix of geology, with acid clay-with-flints capping the chalk, allowing calcicolous and calcifugous species to grow right next to one another. The woods also often support particularly interesting assemblages of ferns (who cares about the helleborines!), and would be just the right habitat to re-find Oreopteris limbosperma (lemon-scented fern), not seen in Oxon for many decades. As it was, we didn't find it but spent quite a lot of time examining ferns belonging to the Dryopteris affinis aggregate (scaly male ferns), some of which were impressively enormous.

Stadhampton Square Bash

Puccinellia distans along the A329

Last Sunday was another square bash, when we moved on to Stadhampton (SU69E) from our previous visit to Little Milton (SP60A). Sorry it has taken me so long to write the meeting up! Let's see if I can make it a short one for a change.

As last time we started off with coffee and cake — may this become an established tradition, especially as the weather begins to turn cooler! Many thanks to Fay Banks and her granddaughter for baking delicious brownies for the four of us. After this pleasant diversion from the task of the day we headed out recording. When botanising any village a priority will always be the churchyard and this is where we went first. It was the usual disappointment, ruthlessly mown, but sported Galium verum (lady's bedstraw), Pimpinella saxifraga (burnet saxifrage) and Plantago media (hoary plantain),  a typical assemblage of hangers-on in over-managed churchyards. We did find Epilobium x limosum in a weedy patch, the hybrid between the broad-leaved and hoary willowherbs — no surprises to learn on getting home that this hasn't been much recorded in the county.

Two buckler ferns: the broad Dryopteris dilatata (left) and the narrow D. carthusiana (right). The latter used to be called D. spinulosa on account of the long drawn-out points to the pinnule lobes, and it lacks the distinctive black-marked rachis scales and convex shape of the pinnules seen in D. dilatata.

Stadhampton pond infested with Myriophyllum auqaticum

Square bashing is mostly about gathering as many records as possible from a square, and in settled places this usually consists of alien species, but one seldom fails to find something of interest. Along the A329, for instance, we had a couple of decent and probably under-recorded grasses: Puccinellia distans (reflexed saltmarsh grass), a colonist of salted roads whose natural habitat as the name indicates is on the coast; and Polypogon viridis (water bent) a grass that been expanding in range very rapidly in urban places over the last decade or two but as yet has few Oxon records. Other aliens were in plentiful supply, particularly the invasive Myriophyllum aquaticum (Parrot's feather) which had taken over the pond on the village green.

Returning to natives, the limestone walls of the village had the usual Polypodium (polypody fern), unidentifiable at this time of year. However, a little later on once we'd got out in more semi-natural habitat we came upon a nice big stand of well-behaved Polypodium growing on a concrete bridge over a stream and which was clearly P. interjectum. As I've commented in previous posts this would seem to be our commonest Polypodium species. A little further on we came upon some lovely alder woodlands that had developed over a series of medieval fish ponds. Often getting good records is a matter of knowing what to look for in particular places, and here we managed to find the wet woodland fern Dryopteris carthusiana (narrow-leaved buckler fern), a pretty scarce plant in Oxon. Interestingly, the few recent records come from Chiltern beechwoods, an atypical habitat.

The woodlands served us well and were a nice contrast for a square that mostly comprised artificial habitats. The total for the square is now 250 taxa, a considerable improvement from the 9 it had stood at. Many thanks to those that attended.

Somerton and the Oxford Canal

Botanists botanising by the Oxford Canal. Remark the use of modern technology. Image by Fay Banks

Recording for Atlas 2020 in Oxfordshire continues. The target of this Sunday's meeting was the county's most under-recorded 10km square, SP42. Earlier in the spring I wrote about a recording outing of mine in SP42 at Tackley, and this week the venue was the parish of Somerton in SP42Z, further north along the River Cherwell/Oxford Canal. There will be another meeting in SP42Z on 8th July at Bestmoor SSSI, when we will survey the huge population of the nationally scarce Oenanthe silaifolia (narrow-leaved water-dropwort).

Sporangia of P. interjectum x100, with few thick-walled (indurated) cells forming the annulus and two basal cells between this and the stalk

The five of us who met at Somerton were blessed with wonderful weather and some fabulous plants. We started at the churchyard of St James’ which was a tidy disappointment, however. An exhibitor at the church exhorted us to come in afterwards for coffee and artwork, but we conveniently forgot and instead went to the Bell Inn in Lower Heyford! The only interesting native species in the village was a large amount of the fern Polypodium interjectum (intermediate polypody) on a shaded wall. Contrary to previous records I am finding that this is a common fern of limestone walls in Oxfordshire. I’d be grateful if other recorders would check any Polypodium they find microscopically, or record it as P. vulgare sens. lat. rather than attempt an identification based on frond morphology as this is not reliable.

We left Somerton southwards across bright green agricultural grassland and wheat fields infested with Alopecurus myosuroides (black grass). At this point I began to worry about our species list. A short detour out of SP42Z into SP42Y gave us Senecio viscosus (sticky groundsel) by the railway, from where we looped back into our tetrad and picked up the Oxford Canal. From here our fortune turned.

Lower Deans Wood & Watlington Park

Four botanists met at Watlington Hill (SU79) on a cold but bright morning last Sunday, 22^nd January, to explore the nearby Lower Deans Wood. The focus of the meeting was bryophytes, but vascular plants were also recorded. This is an account of what was found.

Recording highlights from 2016

As the miserable weather settles on us and we enter the season of armchair botanising (at least for higher plants), I offer my reflections on what has been a very rewarding season. These highlights are based on exciting plants I've seen this year and range from new county records and new sites for county rare plants, to re-finds of plants thought potentially extinct in the county. I can think of many further delights I'd have liked to have included, but at least that leaves plenty of material for other posts. Do let me know if there's anything you'd like to share.