Allolee to Walltown facts for kids
| Site of Special Scientific Interest | |
| Area of Search | Northumberland |
|---|---|
| Coordinates | 54°59′45″N 2°29′25″W / 54.99581°N 2.49037°W |
| Interest | Biological |
| Area | 33.9 hectares (84 acres) |
| Notification | 1991 |
| Location map | DEFRA MAGIC map |
Allolee to Walltown is a special natural area in Northumberland, England. It is called a Site of Special Scientific Interest (SSSI). This means it's a very important place for nature. It is protected by law because of its unique plants and geology.
This SSSI follows a part of Hadrian's Wall. It is famous for having many different types of grasslands. These grasslands grow on thin soil. This soil sits on top of a special rock formation called the Whin Sill. The Whin Sill is unique to the Northern Pennines area.
Where is Allolee to Walltown?
Allolee to Walltown is in the north-east of England. It is about 1.6 miles (2.6 km) east of Greenhead. It is also about 2.2 miles (3.5 km) north-west of Haltwhistle.
The site is a long strip of land. It stretches for about 1 mile (1.6 km) along Hadrian's Wall. It goes from Milecastle 45 (Walltown) in the west. It ends near Turret 43B in the east. This is close to the old Roman fort of Aesica (Great Chesters). Milecastle 44 (Allolee) is roughly in the middle of this special area.
The Whin Sill and its Plants
The land here sits on the Whin Sill. This is a type of igneous rock called dolerite. Igneous rocks are formed from cooled lava. The Whin Sill forms tall, rocky cliffs. The Romans used these cliffs for strategic defense when building Hadrian's Wall.
The rock of the Whin Sill makes the soil here special. It is less acidic than other similar rocks. The soil on top is thin and a bit peaty. This creates a perfect home for certain plants. These plants can handle dry conditions. A notable plant here is wild chives (Allium schoenoprasum). Wild chives are rare in Northumberland, except on the Whin Sill.
Different Grasslands and Flowers
The thin soil at Allolee to Walltown supports many interesting plants. Besides wild chives, you can find biting stonecrop (Sedum acre). There is also hairy stonecrop (S. villosum) and wild thyme (Thymus praecox). Other plants include parsley piert (Aphanes arvensis) and common whitlow-grass (Erophila verna).
The grasslands around the drier areas have different grasses. These include red fescue (Festuca rubra) and common bent (Agrostis capillaris). You might also see sweet vernal-grass (Anthoxanthum odoratum) and heath grass (Danthonia decumbens).
On the rocky cliffs and north-facing slopes, you'll find other plants. These include bilberry (Vaccinium myrtillus) and heather (Calluna vulgaris). Fir clubmoss (Lycopodium selago) and parsley fern (Cryptogramma crispa) also grow here. Green spleenwort (Asplenium viride) is found on limestone outcrops.
Some areas have more calcareous soil. This means the soil has more lime. These areas support grasslands rich in herbs. Here you can find meadow oat-grass (Avenula pratensis) and quaking grass (Briza media). Other plants include dyer's greenweed (Genista tinctoria) and common rock-rose (Helianthemum nummularium).
One part of the site, east of Allolee, has poor drainage. This area has a very unusual grassland. It is mostly purple moor-grass (Molinia caerulea). But it also has many other species. These include quaking grass, meadow oat-grass, and several types of sedge. You can also find lady's mantle (Alchemilla filicaulis), lady's bedstraw (Galium verum), and cowslip (Primula veris).
