Clematis
What are they?
The genus Clematis is placed in the highly diverse Buttercup Family (Ranunculaceae) and has a number of features typical of the family. Instead of independent whorls of sepals and petals, the flowers have a single whorl of structures that are usually colourful like petals but also function like sepals, protecting the flower when still in bud. These dual-purpose structures are often referred to as 'tepals'. Clematis species typically have four tepals, but many cultivated hybrids have six tepals. The flowers also have a large number of stamens and, after flowering, the free carpels swell to become dry fruits called achenes, each bearing a feather-like projection.
Where are they found?
Our one native species is common to abundant in scrubby woodland and hedgerows on chalk or chalky boulder clay, being far less common on sandier soils. Other species are rare but recorded now and again from mostly urban locations as escapes or relics of cultivation.
Identification
Clematises are strong climbers with wiry stems and cling by means of twining leaf stalks. They can all appear fairly similar in their leaves (though some are clearly have broader leaf segments than others) but can be quite easily separated by their flowers.
Traveller's-joy Clematis vitalba
(Wild Clematis, Old Man's Beard) Native and very common in scrub, woods and hedges on chalk and chalky boulder clay. Occasionally in urban areas as a survivor from earlier plantings where this species has been used as a rootstock for ornamental varieties. Flowers July to August. A very vigorous and persistent climber which may grow to 6m or more in height and trail through surrounding vegetation. Flowers have small, greenish-white tepals which soon drop after pollination, leaving a fuzzy cluster of stamens. Leaves one-pinnate with three or five leaflets.
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Virgin's-bower Clematis flammula
Introduced from southern Europe as a garden ornamental. Recorded once at Tattingstone, Suffolk. Flowers June to July. A vigorous and bushy climber. Flowers have tepals that are longer, whiter and more prominent than those of our native species and the flowers are very fragrant. Leaves twice-pinnate with the leaflets variously rounded and lobed.
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Early Virgin's-bower Clematis cirrhosa
Introduced from the Mediterranean region as a garden ornamental. Recorded from Cambridge and from Holme-next-the-sea, Norfolk. Flowers irregularly during the winter months into early spring. A vigorous, wiry climber. Easily told from other Clematis species by its simple, not trifoliate leaves. Flowers creamy, sometimes with dull reddish spots on inside of the petals.
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Himalayan Clematis Clematis montana
Introduced from eastern Asia as a garden ornamental. Common and very popular as a garden plant but only rarely recorded in the wider countryside. Flowers April to May. Flowers have relatively large, broad tepals that may be pink or white. Leaves twice-pinnate with the leaflets variously rounded and lobed.
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Orange-peel Clematis Clematis tangutica
Introduced from eastern Asia as a garden ornamental. Recorded as having self-seeded into the wild on three occasions in the East Anglian region. Flowers April to May. Flowers nodding, solitary in the leaf axils. Leaves oncce-pinnate with the leaflets relatively narrow and often irregularly lobed.
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Armand's Clematis Clematis armandii
Introduced from China as a garden ornamental and recorded from Cambridge. Flowers March to April. A vigorous, evergreen climber. Flowers variable, with 4-7 white tepals. Leaves glossy with stout, parallel veins.
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