A collection of wildlife photographs

Tuesday, 5 August 2014

A botanical excursion to Fulbourn Fen

On 29th June, I went to Fulbourn Fen to look for Orchids. Although this Fen is currently owned by the Wildlife Trust, it previously supported the large Dunmowes Manor in the Medieval period. This manor had a moat, used either for defence, keeping out wild animals, or the projection of high status. The Fen is now home to a high diversity of plants because the grassland on this site remains unimproved by fertilisers, pesticides or livestock.

Woodruff Galium odoratum
The entrance to the site is through some woodland, where abundant Woodruff Galium odoratum grew. Woodruff is an ancient woodland species (see Rose, 1999 for comprehensive lists), and so this piece of woodland is likely to have been growing here for at least 400 years. However, the presence of multiple ancient woodland indicators are generally required to unequivocally classify a habitat as ancient woodland. Woodruff can be identified by its whorls of 6-8 elliptical-lanceolate (lance-like) leaves growing outwards from a single point on its stem. These leaves have pointed tips, as shown in the photograph to the right, and are 25-40mm in length. When the leaves are bruised they release a vanilla scent, and when mature, the plant is between 15 and 45cm in height.

Field Scabious Knautia arvensis
The path then spilled out into a calcareous grassland, indicated to by the abundant Field Scabious Knautia arvensis. Its distinctive lilac flower make it a conspicuous member of calcareous grassland communities. The leaves on its stem usually unlobed but sometimes have blunt lobes. Its leaves are opposite and coarsely hairy. Additionally its stem is densely covered in hairs, as shown in the photograph to the right.

Meadowsweet Filipendula ulmaria
Also in this grassland was frequent Meadowsweet Filipendula ulmaria. Its leaves which are shown in the photograph to the right, are divided into 2-5 pairs of main leaflets, with tiny leaflets of 1-4mm length between these. Its leaf stalks smell strongly of germolene antiseptic creme when freshly broken. The flowers of Meadowsweet are creme in colour and arranged in a similar way to umbellifers (plants from the carrot family), despite this species being from the Rose family. This herbaceous perennial grows best in damp ditches, meadows and riverbanks.

Meadowsweet Filipendula ulmaria flower

Hogweed Heracleum sphondylium also grew in this calcareous grassland. It has distinctive basal leaves, which are once-pinnate (i.e. each leaf is divided just once into opposite leaf lobes and each lobe is not divided a second time to contain another set of opposite lobes) as shown in the photograph below. Hogweed is roughly hairy on its stems and produces white or pinkish umbel flowers. This species is commonly found growing on  roadsides, hedgebanks, grasslands and woodlands.

Another species, Giant Hogweed Heracleum mantegazzianum, appears similar to Hogweed apart from being larger, growing to 3m in height, and having red spots on its hairy stems. However, Giant Hogweed is highly invasive and can cause rashes and blistering, by causing the skin to become overly sensitive to UV rays, so should be avoided. If found growing, Giant Hogweed should be removed by an invasive species specialist, as it is listed as an invasive non-native species under Section 9 of the Wildlife and Countryside Act (1981).

Hogweed Heracleum sphondylium

White Bryony Bryonia alba
After going on up to Fleam Dyke, an enbankment previously used to divide two separate Anglo-Saxon territories, I discovered numberous climbers amidst the hedgerow. The first I noticed was White Bryony Bryonia alba which has bristly stems which are angled as shown in the photograph to the right. This perennial has spirally-coiled tendrils, which are used to grip on things to help the species climb, growing from the side of its leaf stalks. The leaves of White Bryony are palmately lobed (i.e. five lobes like the palm of  hand). Its flowers are pale green, with both male and female parts. The male flowers have 5 sepals as shown in the photograph below, however the female parts of the flower are oval, dark green and have 3 stigmas (the extensions which trap pollen and stimulate them to germinate). This species is typically found on hedgebanks, scrub, the edges of woodland and appreciates calcareous soils.

Traveller's Joy Clematis vitalba
The next climber I spotted was Traveller's Joy Clematis vitalba. As shown in the photograph to the right, the compound leaves are arranged in pairs of opposite leaflets, which are narrow, oval and pointed. The leaves can be toothed, although those in the photograph are not extensively so. The flowers are fragrant and have 4 creme-green sepals (the whorl of floral leaves below the petals), with hairs on their upper and lower sides. The flower supports many long stamens from its centre, and often the petals drop, so that the flower is comprised primarily of these extensions. Although originally introduced to the UK as a garden plant, its seeds soon escaped the gardens and now this species is found frequently on chalk and limestone soils.

Black Bryony Tamus communis
Further along the embankment I found frequent Black Bryony Tamus communis. This perennial climber twines clockwise and lacks the tendrils of White Bryony. Its leaves also differ from White Bryony; the leaves of Black Bryony are cordate (i.e. with a heart shaped base), pointed, and very glossy as shown in the photograph below. The flowers of Black Bryony are yellow-green in colour, bell-shaped and have 6 perianth lobes (perianth being the collective term for sepal and petal segments, when they are indistinguishable in colour and form). The male parts of its flower are on stalks and the female parts are more or less stalkless. Black Bryony produces poisonous red berries, so do not go near it if foraging. It has also been introduced to the UK, and is typically found in open woodlands, scrub, hedgebanks, particularly on calcareous soil.

Then finally, after arriving at the Marshy part of the grassland, there were several Orchids. At this stage in late June, most of them, such as the Southern Marsh Orchid Dactylorhiza praetermissa and Early-purple Orchid Orchis mascula had gone over, and their flowers had wilted. However, some Bee Orchids Ophrys apifera, were still in vibrant flower. This species produces large several conspicuous flowers per plant, positioned up the stem. The sepals of its flowers are rosy pink to whiteish and slightly pointed, as shown in the photograph below. The lip of its flowers is reminiscent of a bee, being furry and rich-brown in colour, giving this species its common name. A pale-yellow U or W-shaped area is superimposed onto the rich-brown lip. The Bee Orchid grows to 10-40cm in height, with grey-green leaves which are elliptical-oblong in shape. Bee orchids tend to grow on calcareous grasslands, dunes, disturbed ground and quarries, and are an attractive botanical addition to all habitats in which it is present.
Bee Orchid Ophrys apifera
This was a species-rich grassland, and the careful management by the Cambridge Wildlife Trust made sure that it lacked improvements through fertilisers, pesticides and the excrement of grazing livestock which would alter the soil and act to reduce botanical diversity. The protection of some areas from such 'improvement' is vital in conserving some species, which only grow in unimproved grassland.

Rose, F., 1999. Indicators of ancient woodland: the use of vascular plants in
evaluating ancient woods for nature conservation. British Wildlife. 241–251.

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