FIG 33. Peninnis Head is a jumble of extraordinary granite tors. May 2005. (Rosemary Parslow)
so a different range of arable weed species is found among the crop: these include some of the goosefoots Chenopodium spp. as well as the ubiquitous corn marigold Chrysanthemum segetum, docks Rumex spp., shepherd’s-purse Capsella bursa-pastoris and sow-thistles Sonchus spp.
Above Hugh Town is the high, rocky promontory of the Hugh, almost completely surrounded by the granite walls of the early fortifications of the Garrison. Here the long history of the Garrison is marked by an array of buildings, defence works and other structures. English Heritage manages most of the historic buildings and walls that form the Ancient Monument. There are some areas of semi-natural vegetation within the fortifications managed by the Wildlife Trust, mainly areas of bracken and bramble thickets, rough heathland and mown grassland. Some of the windbreaks of Monterey pine have died but there are still more pines and other trees on the eastern flank of the promontory. On the slopes of the hill Babington’s leek and balm-leaved figwort both grow among the bracken and bramble. And a few stands of the Nationally Scarce wild leek Allium ampeloprasum can also be found here, probably overlooked because they were assumed to be the commoner Babington’s leek variety. On the exposed southern side of the Garrison there are more maritime habitats from below the walls to the rocky shore (Fig. 34). There is also a row of tiny abandoned gardens perched on the edge of the cliffs. The thin soils on top of the massive granite walls often support a therophyte community (therophyte plants overwinter as seeds and germinate in spring) of dwarfed species of grasses and forbs similar to that seen on natural granite outcrops around the coast. Where they are permitted to flourish, small ferns such as sea spleenwort lodge in the mortar between the granite blocks, as do other plants that are usually found in rock crevices on the cliffs: Danish scurvygrass Cochlearia danica, pearlworts Sagina spp. and thrift Armeria maritima are frequent examples.
Other interesting species of ferns and other plants grow on both sides of the high granite walls. Between the ramparts are mown lawns that in some places are still typical of coastal grasslands with a tight sward of fescues Festuca spp., buck’s-horn plantain Plantago coronopus, sheep’s sorrel Rumex acetosella, small-flowered catchfly Silene gallica, western clover, rough clover Trifolium scabrum and other clovers. Besides the usual resident birds, the coastal area and the shelterbelts are good venues at bird migration times to look out for species such as wheatear, wryneck Jynx torquilla and black redstart Phoenicurus ochrurus. One section of wall near the Woolpack Battery is remarkable for the hundreds of autumn lady’s-tresses orchids Spiranthes spiralis that flourish there just at eye level in late summer.
FIG 34. Exposure to southern gales restricts growth on the seaward side of the Garrison walls to lichens, tiny ferns and a few other plants. November 2002. (Rosemary Parslow)
QUARRIES
There are a number of former quarries on St Mary’s. Most are overgrown or incorporated into fields, and many are unlikely to be noticed. One you cannot miss is on the side of Buzza Hill. Rising up from Porth Cressa beach, the hill is a popular vantage point to look out over the town and beach below. The quarry at the foot of the hill is mainly used as an informal picnic or rest area and has a mixture of scrub and rough vegetation as well as grassland in the base. Among the plants that have colonised the walls of the quarry are Hottontot fig and another South African succulent, lesser sea-fig Erepsia heteropetala. Another unusual alien grass, rough dog’s-tail grass Cynosurus echinatus, also grows all along the sides of the track up the hill, usually with greater quaking-grass Briza maxima and tall stands of yellow and occasionally white sea radish Raphanus raphanistrum maritimus. Further up the hill yet another unusual alien called wireplant Muehlenbeckia complexa scrambles over the walls, covering most of the vegetation and even the ground with dense wirelike growths so it becomes a kind of mad sculpture. Once at the top of the hill you reach Buzza Tower (a former windmill restored to commemorate a visit by King Edward VII), surrounded by scrub, tall grasses and herbs. The shrubs include broom (probably native here) as well as gorse and bramble.
At the top of Buzza Hill you will find you are on the edge of Hugh Town again and there are many houses, some of which are guesthouses. Inland at Carreg Dhu (pronounced, and sometimes written, as Crake Dew) is another former quarry. This has now been developed as a garden open to the public (see Chapter 13). There is also the former quarry on the Garrison, which has now vegetated over and is probably generally passed unobserved. Other small quarries exist all around the island, and may have just been used very locally to produce building stone or ram.
PORTHS AND BAYS
Because part of St Mary’s straddles a sand bar there are two bays with sandy beaches, Porth Cressa on the south and Town Beach on the north within the Pool (harbour). Porth Cressa lies between the two headlands of Peninnis, the long promontory stretching to the south, and the Hugh, the hill surmounted by the Garrison with the town creeping up its flanks. Porth Cressa is one of the most accessible and popular bays with families and visitors staying locally, because of its proximity to the town and local amenities (Fig. 35). Although it is usually a sheltered bay, the area has proved extremely vulnerable when there are storms from the south. In the past the sea has broken through on a number of occasions and threatened to wash away the buildings (which are virtually only perched on the former sand dune) and eventually cut through into the Pool on the other side of the island. In recent years major defence works have been carried out along Porth Cressa beach to reinforce the sea bank and protect the town. There is perhaps little of great interest yet along the beach, due to the landscaping when the bank was restored, although arable weeds are reappearing in the flowerbeds and some of the sand-dune plants such as sea radish and yellow horned-poppy Glaucium flavum are colonising the beach defences. Town Beach has slightly more muddy sand, and is where all the mooring lines from the smaller boats in the harbour are stretched ashore.
There are several bays on the east coast of St Mary’s. Old Town Bay is quite rocky but with clear channels into the harbour, sheltered from all directions except southeast. The harbour is only accessible at high tide. Near the narrow sandy beach are patches of tree-mallow Lavatera arborea, smaller tree-mallow L. cretica, sea radish, white ramping-fumitory Fumaria capreolata and other plants
FIG 35. Porth Cressa, July 2006. (Rosemary Parslow)
that flourish in the disturbed sandy ground. The sea wall was rebuilt