BBS Field meeting, SE and Southern group joint meeting
Harting Down is a large area of rolling downland with well grazed chalk grassland and mixed woodland with mature scrub. There are a fair few previous bryophyte records including the rarities, Rhodobryum roseum, Dicranum bonjeanii, Loeskeobryum brevirostre and Thuidium assimile but it is a huge site and some areas are unexplored territory.
A group of 12 bryologists assembled in the car park and set off at a brisk pace across the top of the north scarp with stunning views down to the village of East Harting. We weren’t quite as speedy as a border collie who tore past us having been spooked by an electric fence but a sprint in mossing terms and some of the group overshot the first interesting stop.
The path dropping down to Whitcombe Bottom and wound through grassland dotted with anthills. The mosses mentioned above had been found in the next valley, Bramshott Bottom, but that was full of cattle on our recce so we took a chance on Whitcombe Bottom.
Bryums filled gaps in the short grass on the mounds and we noted Bryum rubens with large red tubers visible at the stem base and in the earth, Bryum dichotomum with green bulbils between the leaves and Bryum ruderale with rough, purple rhizoids. As well as emerald green moss some patches were pink tinged and I checked one sample, hoping to identify B. pallens which is characterised by salmon-tinged leaves and has been found near here before. Large, red tubers and pear shaped bulbil-like leaflets appeared when the sample was soaked. I sent it to Tom Ottley who identified it as just more B. rubens.
John Norton had spotted the orange fungus Octospora gemmicola growing on more typical Bryum rubens on our recce and he re-found this to show the group and discovered another two colonies on neighbouring anthills.
These anthills weren’t particularly varied so we carried on down the valley, checking a small Elder with hairy armpits of moss in all the branch axils where damp collects and the branching offers some protection from the elements. The epiphytes included four Orthotrichums including O. pulchellum with capsules just emerging. Along the branches Metzgeria violacea grew with gemmae clustered on the tips of its thalli.
A pair of Cherry trees were also well checked and a nice selection of epiphytes including Zygodon conoideus, Microlejeunea ulicina, Radula complanata and Ulota bruchii were found.
The valley of Whitcombe Bottom curved between three tetrads and there were hundreds of anthills in the turf which needed checking. Some areas were dominated by coarse grasses so we gave these a miss but much of the area is closely cropped. The National Trust graze the grassland with sheep and handsome Belted Galloway cattle and a healthy population of rabbits help out too.
We all ranged across the area until someone yelled “Rhodobryum” and we all converged, scampering up the hill to have a look. Rhodobryum roseum is an attractive moss of grassland and always a delight to find and this was a new site and tetrad for it. It likes to grow on and around anthills and the large leaves of its terminal rosette is distinctive and striking. Now the task turned to counting anthills with colonies of Rose Moss rather than keeping count of free range bryologists. Nestled in the turf were small tufts of Dicranum bonjeanii with its transversely wrinkled leaves, another of the rarities that we had hoped to find. John identified Weissia controversa var. controversa from an anthill, the capsules just mature enough to check the peristome. On the recce we had found Weissia longifolia var. angustatum with immersed capsules but didn’t spot it this time.
Lower down, nearer the path and sheltered by trees a group of anthills supported a different community of mosses. The long-leaved moss here was Pleuridium subulatum and it was growing with Ceratodon purpureus. Pete Flood took some Pleuridium home and found tiny shoots of Ephemerum minutissimum hidden beneath. He checked the spores had hyaline membranes and the leaves had some recurved teeth.
The group fanned out again, looking for Loeskeobryum brevirostre below the tree line but none could be found and we converged again to eat lunch, sitting on more anthills and noting a single Harebell flower.
We had resisted the woodland to the right but a large Beech tree drew everyone away from the path. The roots were wrapped in Isothecium myosuroides or Mousetail Moss, much of it fruiting. John checked the leaf bases of a swathe of fruiting Brachythecium on a rotten log and they had the decurrent base of B. rivulare. Anna picked up some Rhynchostegium confertum, bristling with capsules, from a tree base. Another common epiphyte, Hypnum andoi was also fruiting with mammillate capsule lids.
The woodland floor was carpeted in Eurhynchium striatum, Thuidium tamariscinum and the odd patch of shiny tipped Cirriphyllum piliferum.
Zygodon conoideus was frequent on trees and some of it was fruiting.
At the edge of the scrub a slim Ash tree had a frill of Orthotrichum lyellii emerging from a disc of the leafy liverwort Frullania dilatata.
David Streeter handed me a tiny pleurocarp found growing on flint in the woodland. It was Heterocladium heteropterum var. flaccidum with leaves measuring just .25mm just visible with a hand lens. This moss is familiar from dry stones in gill woodland on the Weald but I hadn’t seen it growing on flint before.
We still hadn’t reached the prime bit of grassland and there was one last distraction in the form of a dewpond. A few of us climbed the fence and recorded sturdy Bryum pseudotriquetrum, fruiting Tortula truncata and Pseudocrossidium hornschuchianum with its recurved leaf margins, all frequent in the damp pond margin.
We eventually got to the area where we had found swathes of Rhodobryum roseum on the recce, (also a new site and tetrad), but crying Rhodobryum didn’t work immediately the second time. When we did all reconvene, our numbers had grown as a pair of teenagers out walking with their dad were curious as to what we were doing and were thrilled to be shown a rare moss. Maybe they will be inspired to join us on future trips! John noticed a black fungus or rust on Rhodobryum leaves when he looked at his photo at home, (see top image) but we failed to find this again in the fading light despite checking many colonies of the moss. We did find both common Dicranum scoparium and rare D. bonjeanii this time, having just found D. scoparium before.
There were still a few typical mosses of chalk grassland that we were missing. Rhytidiadelphus triquetrus eventually turned up but just in small quantities. Homalothecium lutescens, usually abundant in this habitat was recorded by Francis Rose in 1990 but it wasn’t found on this field meeting. We only found small colonies of Fissidens dubius but one clump was fruiting which we don’t often see. Plagiomnium affine was frequent throughout the shorter grassland.
The sun was dropping fast so we headed for a narrow track through the woods. We didn’t anticipate finding much to slow down our progress but a large moss ruff on a small tree trunk brought us to a halt. It was unusually vigorous Fissidens adianthoides with shoots measuring nearly 6cm. We had only found the similar F. dubius in the grassland where we might have expected to find F. adianthoides too so this was a welcome find.
Another moss that was absent from our list from the grassland, Ctenidium molluscum, appeared on the roots of a tree, in sculptural, feathery form.
We found a few chalk rocks covered with tiny leaves of Tortella inflexa growing from a dark protonemal mat, it’s thin, dark green leaves upright in the damp. When dry the leaves curl tightly and look quite different.
On the home stretch, walking through woods parallel to the road a huge upturned tree created a wall of bare chalk on which Steve Lemon found both Seligeria calycina and the rarer S. calcarea.
Pete F. noted a range of fungi: Clitocybe metachroa, Lycoperdon pratense, Hygrocybe virginea and Rickenella fibula in the grassland and Scutellinia scutellata, Cylindrobasidium laeve, Peniophora quercina and Clitocybe geotropa in woodland.
We had crossed three tetrads during our trip. The first two, SU71Y and SU71Z were already well recorded but hadn’t been surveyed for about 20 years. SU81D only had 18 previous records and we were able to add a good few new species to this area including magnificent colonies of Rhodobryum and a few other notable bryophytes. We didn’t touch on SU81E where most of these rare mosses and a few more have been found previously. There is plenty more work to be done across the whole site.
Many thanks to John for co-leading, Brad, David, Steve, Pete H, Pete F, Nick, Liz S, Liz T, Marcus and Anna for their good company and help with identifications and photo contributions and to Tom Ottley for help with tricky identifications.