Sedges are perennial plants that belong to the Cyperaceae family. The so called ‘true’ sedges are in the Genus Carex and typically have solid three angled stems. The flowering heads are arranged in male and female spikes. Typically they have solid three angled stems.
Pendulous sedge forms a large striking plant with drooping flower heads. A closer view shows the male flower spike at the top with the females strung below. This sedge has edible seeds and fibrous foliage. It has been widely used since Neolithic times as a source of food, since the seed heads are not subject to ergot (Claviceps) infection.
Wood Sedge ( Carex sylvatica) also has a single male flower at the top with three to five stalked female spikelets underneath. I have only ever seen one specimen of the plant in Armstrong Park.
Brown sedge (Carex disticha) prefers damp marshy ground.the flowers are dense and untidy with an unusual arrangement. The terminal spike is female, followed by a male spike then another female.
The Common bluebell (Hyacinthoides non-scripta) is a classic plant of ancient and semi-ancient woodlands. It is a bulbous perennial with a drooping habit, one- sided inflorescence and six strongly recurved tepals. Vivid violet/blue in colour sweetly scented, it has three to six linear shaped leaves.
Flowering under the still -to -leaf trees it can form a massed carpet of deep blue. Although Jesmond Dene is not a famous Bluebell Wood it still provides a good show. Since Bluebells take five to seven years to flower it is a good indicator of ancient woodlands.
Identifying a bluebell to species is not straightforward. The introduction of the Spanish Bluebell (Hyacinthoides hispanica) has led to interbreeding to form hybrid bluebells (H x massartiana), common in gardens. The Bluebell on the left has features characteristic of the Common Bluebell including parallel sided flowers and deeply recurved tepals. The one on the right has an upright habit, erect flower spike, not one- sided with bells open shaped around the stem.
A close up of the flowers shows another difference. The outer stamens on the Hybrid on the right are unfused with the sepals for most of their length but in the Common bluebell (on the left) the stamens are mostly fused.
It is difficult to distinguish between hybrid and Spanish bluebells. The picture below has many characteristics of the Spanish Bluebell including pale flowers and much broader leaves.
The flowers in the picture below display the intermediate features of the Hybrid type.
The Scottish Bluebell is a completely different flower, the Harebell (Campanula rotundifolia).
Liverworts are green flowerless plants that belong to the Plant Division Marchantiophyta. They reproduce by means of spores or asexually by gemmae. Gemmae are single cells or masses that can detach from the parent plant and develop into a new individual. Liverworts are often found in damp places and usually divided into leafy varieties having stems and leaves, or thallose, looking like green leafless pads.
Jesmond Dene has a good show of Common Snowdrops (Galanthus nivalis) this February, drifts merge to form carpets of green and white. Galanthus derives from the Ancient Greek meaning ‘white flower’; nivalis is Latin for snowy. A member of the family Amaryllidacae, it usually flowers before the Spring Equinox and although naturalised is not thought to be native to the British Isles.
A closer view shows the linear grass like leaves, three outer and inner ‘tepals’ and green chevron shape shapes on inner tepals.
Double flowered varieties of common Snowdrop are relatively common, their flower is more lamp shade shaped.
The Greater Snowdrop (Galanthus elwesii) had wider leaves with hooded tips. It is larger than the common variety with green markings that extend over the whole inner tepals.
Galanthus woronowii, the Green snowdrop has much brighter green leaves, slightly more pleated and distinctly notched inner tepals. Both of these subspecies occur along Jesmond Vale Lane.
Although many of the leaves have fallen, oak leaves sometimes overwinter on the tree due to their high tannin content. A comparison of leaves shows the difference in petiole (leaf stalk) length between the three common species. The book on which they rest acts only as a contrasting background.
English or European Oak has no leaf stem (petiole) and the base of the leaf has ‘ears’ on either side of the stumpy petiole. Leaves are about 10cm long tending to grow in bunches as in the example below.
Sessile Oak is the native UK species. These examples come from the trees growing in an area of semi-natural ancient woodland in Armstrong Park. It is distinguished by its stalked leaves and acorn cups. Quercus robur and Q petraea often hybridize to produce intermediate forms with characteristics of both species. The hybrids often have larger leaves.
The third common species is the Turkey Oak (Q cerris), introduced in the 18th century, it has longer irregularly shaped leaved with long stalks. The Turkey oak plays host to the gall wasp (Andricus quercuscalicis), whose larvae damage the acorns of native British oaks. The resulting distorted Knopper galls are frequently found in the Dene scattered on the ground.
This Lucombe Oak is another cross and is a hybrid evergreen although some leaves fall in the Autumn. There is a specimen in Armstrong Park near the windmill. It can be identified by the whisker hairs on the on the tips of the end buds as shown below.
The Lebanon Oak along Red Walk has slender glossy leaves with bristle-tipped triangular lobes.
With large red leaves and whiskered teeth, the Red Oak leaf is unmistakable. There is a splendid example in Coleman’s field.
The Pin Oak, another North American import, has smaller leaved than the Red Oak with buff drifts of hair under the vein joints.
Oak buds, from which next years leaves will emerge, are bunched at the twig tips.
After the ravages of Dutch elm Disease in the 1960’s, Elms seem to be staging a recovery, some growing into substantial trees as above. They may still succumb to a re-emergence of the disease but are growing in several areas in the vale.
The bark still shows pale brown ridges of a tree yet to mature.
This subspecies was susceptible to DED because they are mostly genetically identical and seldom spread by seed. They spread by suckers into scrubby clumps.
A comparison of leaves shows the size difference between species and varieties.
Ulmus minor var minor has a marked asymmetric leaf base with a narrow taper on the short side. Smooth – leaved elm is found in parks and hedgerows being more resistant to DED since it does reproduce from seed. Sometimes called ‘A phoenix from the Ashes’, the leaves are smooth and glossy.
Wych Elm is common throughout the Dene and thought to be a native. Most are rather scrubby but some are growing into modest trees.
Ash trees lose their leave leaves early in the Autumn but their fruits or keys often persist through the winter. The leaflets of 3 – 6 opposite pairs have a terminal leaf. The leaves are phototropic turning to follow the sun. Gender is a complex issue in the Ash; a continuum between male and female varying with the age of the tree. Presumably the one in the photo is female.
Ash can live for 400 years or longer if coppiced. The mature bark is attractively cross ridged.
Young trees have smooth pale grey bark which wrinkles as it ages.
Unfortunately Ash is susceptible to Ash Die-back Disease, also previously known as Chalara, caused by a fungal infection of Hymenoscyphus fraxineus, an ascomycete fungus. It is now present throughout the UK.
It is most noticeable in young saplings, killing them quickly, although older trees take longer to succumb. The lesions form a diamond shape at first but spread around encircling the bark then killing the tree.
Fortunately, Ash has many genetic types, some producing Sercoridoid glycosides which may act as a defence. These glycosides may also be beneficial in combating the coming threat from the Emerald Ash Borer beetle.
Ash is the third most common tree in the UK providing a dappled canopy ideal for many woodland plants. Its loss would be devastating for the countryside and city green spaces.
There is an unusual large leaved ash growing in the Vale. It appears to be the White Ash (Fraxinus americana), a North American tree.
The leaflet turns a butter yellow in the Autumn and has 7-9 large leaves on leaflets. Some are in paired opposites others more alternate like the one above.
Differences between common and White Ash are apparent from the buds and leaf scar. White ash has a browner, less smooth, terminal bud and the scar has a concave top edge.
Probably giant funnel (Leucopaxilus giganteus) which has a white cap, decurrent gills and no ring. The stipe appears too short for Trooping Funnel.
Russula silvestris is found under beech trees and forms mycorrhizal attachments to them. Since the flesh is white it is probably not the Beech Sickener.
Shaggy Scalycap (Pholiota squarrosa) is easier to identify since it grows at the base of trees and is shaggy all over.
Jelly Ear fungus shown above (Auricularia auricula-judae) is very common on Elder and other deciduous tree. Although it is common and quite palatable in stir fries, foraging for fungi is not recommended. This one was growing in Heaton Park on a fallen log sculpture.
September is a good time to look for fungi appearing in the autumn. Fungi are in their own Kingdom and difficult to identify accurately. The familiar fruiting bodies known as toadstool or mushroom are the ephemeral visible parts of an underground network called a mycelium.