For botanists, the West Sussex town of Henfield is a significant spot since it is where William Borrer (1781-1862) was born and lived for most of his life. Developing an interest in plants from an early age, he collected widely as he travelled around the county on farming business for his father, and built up an extensive correspondence network with people like Joseph Banks, William Hooker, James Smith, and Dawson Turner. His garden was filled with a huge number of interesting plants, many of which can still be found today in the vicinity, as attested by the field meeting reports of the Sussex Botanical Recording Society and the fact that over 500 vascular plant taxa have been recorded in his home tetrad (TQ21C).
His expertise was not just limited to the larger plants, either; his knowledge of marine algae, lichens and bryophytes was also considerable, and he submitted numerous observations to Sowerby and Smith for their English Botany, to Turner and Dillwyn’s Botanist’s Guide, and to several of William Hooker’s works. However, apart from a few minor pieces and a book on lichens, he wrote nothing, and we only know of his expertise from contemporary accounts and from his surviving letters and specimens. Furthermore, few of his records are currently in our data, though we are working on a project to identify them in the nineteenth century literature.
Considering how well his local, surviving vascular plant flora has been recorded, it was surprising that our data for TQ21C only had 11 bryophyte species recorded in it, mostly from the west of Henfield Common, plus a few from Broadmare Common. Intriguingly, our data did include one Borrer record, that of the very rare Tortula wilsonii, which was reported by William Mitten in the 1850s as being “On a sandy bank at Barrow Hill, Henfield, where it has been known to Mr. Borrer for many years”.
So, that was the context and easy justification for a SBRS field meeting to Henfield to focus specifically on the bryophytes, and to use it as a training and refresher session for members less familiar with this group. It was gratifying then that fifteen people turned up in very windy conditions for Sue and I to lead a short walk through one of the Henfield monads.
A good range of species seemed likely, with the route covering several habitats, and varying geology. Starting on the Folkestone Formation of the central part of the town, the route took us south, down the hill on the Greensand, finally ending up by the stream and on Broadmare Common, which is on Wealden Clay.
As it was billed as an introductory session, the last thing we wanted to do was to start off with looking at tiny tufts of miniscule urban bryophytes, so we briskly set off along Cagefoot Lane, until we came to a luxuriant patch of green around a bench on the pavement. This kept us occupied for quite a while, first talking about the larger species, Brachythecium rutabulum, Hypnum cupressiforme var. cupressiforme, and Scleropodium cespitans, and also disentangling the acrocarps, Didymodon insulanus, D. luridus and D. rigidulus. A few yards on and an old brick wall detained us for nearly as long, with its typical community of Bryum capillare, copious Homalothecium sericeum, Tortula muralis, and Rhynchostegium confertum.
At the end of the lane a large house caused us to pause, since that was the birthplace of Borrer, and is now the site of a blue plaque, though it doesn’t mention his bryological activities. At least it mentions that he lived there, unlike the plaque outside Mitten’s house in Hurstpierpoint.
Across the lane from the house is the Tan Yard, a meadow area where cattle hides were processed in the past, which was a good location to introduce everyone to a different range of species. As expected, the grass was accompanied by good quantities of Calliergonella cuspidata and Rhytidiadelphus squarrosus, with a bit of the very common Kindbergia praelonga. A Hazel by the pond gave us our first common epiphytes of the day, Metzgeria furcata and Orthotrichum affine. On the way out of the gate, Sue and I noticed the bright green patches of Pseudocrossidium hornschuchianum on the soil, too, but kept quiet about that in the interests of not overloading everyone too soon with very long names for very small plants.
The Red Oaks care home is also at the end of the lane, and we explored the gardens for some time, first to show the common thallose liverworts of pavements, Lunularia cruciata and Marchantia polymorpha, and then to explore the lawn and flower beds. The latter were surprisingly productive, giving us a cluster of quite different (and identifiable) Bryums: dichotomum with its gemma, the silvery argenteum, and rubens, with its small red tubers. Patches of the lawn also harboured Polytrichum juniperinum, with its spiky, red-brown-tipped leaves.
Sensing that the party was beginning to feel cold, and a bit weary of the new botanical universe we were throwing at them, the time finally came to head down the lane at a reasonable pace, noting a few other typical urban species on the way, such as Didymodon nicholsonii on damp tarmac, Grimmia pulvinata on a wall, and Syntrichia montana on mortar.
This route took us down Spring Hill, where we crossed from the Folkestone Formation to the Greensand and were now in a truly rural space. Keen to explore the banks, we were slightly diverted by an arable field, which was an opportunity to whip out Ron Porley’s book and talk about rhizoidal tubers, while at the same time stressing that, though not especially tricky to determine, the small arable bryophytes are not exactly beginners’ material. Even so we did find Dicranella staphylina, Tortula truncata and Phascum cuspidatum while the cold wind did its best to encourage us to move on.
Now, finally, we reached territory containing a nice range of bigger, common bryophytes that were known to some of the group, and which are easier to identify. The banks at the bottom of Spring Hill were home to Amblystegium serpens, Fissidens taxifolius, Atrichum undulatum, Thamnobryum alopecurum, Mnium hornum, and Oxyrrhynchium hians, and Sue also found a bit of Plagiothecium nemorale. By now it was past one o’clock and we had worked the group quite hard so it was time to stop for lunch, which coincided with a break in the clouds, some sunshine and a diminution of the wind.
Suitably refreshed we now headed east along the stream, quickly stopping to look at the strong-nerved pleurocarp on the rocks, which was Platyhypnidium riparioides, and James scraped a small acrocarp off the stone from just above the water; this turned out to be an untoothed version of Dichodontium pellucidum.
Along the stream-side there were numerous flushes and boggy patches, often with Willow, Ash and Elm. The wet land gave us Leptodictyum riparium with its drawn-out leaves, and Brachythecium rivulare, with its leaf bases running down the stem. The trees here and along Dagbrook Lane were a good source of epiphytes, enabling us to compare Radula complanata with Frullania dilatata, and point out the field characters of other taxa such as Orthotrichum lyellii, Cryphaea heteromalla and Metzgeria violacea, and explain how easy it is to observe the gemmae of Zygodon viridissimus and its relatives.
A staddle stone kept us busy for quite a while, covered as it was in a wonderful mosaic of Grimmia pulvinata, Syntrichia montana, Tortula muralis, and Schistidium crassipilum with its reddish cylindrical capsules. Right next to it, a tarmac drive was carpetted with an amazingly luxuriant coat of Scleropodium cespitans.
Now briskly heading back up Barrow Hill (possibly near the site where Borrer found Tortula wilsonii) we paused on Borrer’s Bank, a managed green space in front of the site of the house Borrer lived in for most of his life, now sadly demolished and replaced with more modern building. Here we observed the distinctively chunky Pseudoscleropodium purum, and Sue also found the rather more refined Pleuridium acuminatum.
Then, up the High Street, and we had to stop again, this time to observe more acrocarps of damp tarmac, this time Syntrichia ruralis with its hair points, and Syntrichia latifolia, without.
And that was it. A fine end to a very intensive bryophyte day, during which we did our utmost to observe that, when you start learning to identify these small plants, it can get overwhelming very quickly. Nevertheless, going out regularly with other people who can show and explain is vital, and it doesn’t need to take that long before you get familiar with the 100 or so common species, and start to develop a nose for the variety of places and habitats to look in, and the subtle shifts in texture and colour that can indicate the presence of something different.
It would be interesting to know how many of the species we saw would have been known to Borrer; a few were certainly not described until many years after his death, though the majority were in the major botanical works on the early nineteenth century. Pleasingly, over the course of the day we recorded 64 taxa, bringing the tetrad total up to 69, which compares well with the tetrad to the south, which includes Woods Mill and has 81 species recorded in it. Since we only covered one of the monads of TQ21C, and even there I am sure we could find other plants, I suspect we can still add a good number of species to the known list from the Borrerlands.
Huge thanks to Sue, and to the very engaged party of botanists who came along. I hope we can see you on future bryophyte outings.
 Some of Borrer’s reports from in and around Henfield in the early literature include Brachydontium trichodes, Tortula modica, Calliergon cordifolium, Leskea polycarpa, Campylium stellatum, Straminergon stramineum, Calliergonella lindbergii, Orthotrichum sprucei, Syntrichia latifolia. Herbarium specimens for some of these may exist, though none are yet included in our Sussex dataset.