The Nettle Family
What are they?
Perhaps best known for the nasty, stinging members of the family, the nettles are a small but rather diverse group. Most are perennials (with one annual) and all have rather insignificant, unisexual flowers, the males with four stamens, the females with a brush-like cluster of stigmas.
Where are they found?
Our two species of true nettle are plants of open ground, either disturbed in the past, or regularly disturbed - such as gardens and arable fields. Other members of the family are plants of urban environments, most often found growing from cracks in walls or paving.
Identification
Once known, the species of walls and paving are easily identified by their plentiful leaves and tiny flowers in the leaf axils. Nettles as a group are told by their course, bristly leaves which will sting if touched! Leaf shape, habitat and structure of the flower clusters are all useful in telling them from each other.
Common Nettle Urtica dioica
An abundant species in our region, some consider this a native species, while others say it may have been introduced by the Romans. Flowers mostly July and August. Tiny flowers carried in abundance in branching spikes, hanging from the upper leaf axils; male and female on separate plants. A vigorous species of waste and formerly disturbed ground, roadsides and shady places, often forming extensive, dominant patches where soil enrichment (such as from agricultural run-off) has occurred.
 |
 |
 |
 |
| |
Male below) |
|
|
Fen Nettle Urtica dioica ssp. galeopsifolia
Found in wet, fen habitats, especially in the Norfolk Broads and in Fenland. Generally regarded as a subspecies of the Common Nettle, the Fen Nettle is sometimes considered a full species, though there are a number of intermediate plants that can make determination difficult and identification may only be truly possible through chromosome counts. It differs from other Common Nettles by its much narrower, elongated leaves and by having only soft hairs and no stinging hairs - a brave identification feature to test!
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Small Nettle Urtica urens
Much smaller than Common Nettle, being a short annual of recently or regularly disturbed ground such as arable margins and allotments. Flowers mostly July and August but can be found throughout much of the year. Differs from Common Nettle in its smaller size, smaller, tighter flower clusters and more rounded, less triangular leaf shape.
 |
 |
 |
 |
| |
|
|
|
Membraneous Nettle Urtica membranacea
Introduced from southern Europe. rare in the UK and mostly found as an urban weed. Appears to be increasing in recent years, with the first East Anglian records coming from Cambridge and Caister-on-sea recently. Flowers May to August. An annual species; male and female flowers on the same plant, the male flowers higher up and in longer, one-sided clusters on flattened stems. The stems bear only two stipules at each node (four in other nettles).
 |
 |
 |
 |
| |
|
|
|
 |
 |
 |
 |
| |
|
|
|
Roman Nettle Urtica pilulifera
An ancient introduction, originally believed to have been brought to Britain by the Romans. Formerly a scattering of records from our region but now thought to be extinct in the UK. Flowers July to August. Differs from other nettles in its flowers and fruits which are clustered into tight, rounded balls.
 |
 |
 |
 |
| |
|
|
|
Pellitory-of-the-wall Parietaria judaica
A native plant of rocky places, but in our area a common plant of walls in urban and rural areas, as well as occasionally on steep hedgebanks and similar places. Flowers mostly June to October. A rather scruffy plant, compact at first, becoming taller as the flowering shoots grow; glossy leaves have well-marked, indented veins. Stems and leaf petioles reddish. Flowers tiny, in small clusters in the leaf axils.
 |
|
 |
 |
| |
|
|
|
Mind-your-own-business Soleirolia soleirolii
Introduced as a garden curiosity from the Western Mediterranean and now well established as a weed of walls, especially in damp places. Flowers May to September. Easily passed off as a moss or liverwort, this plant grows from cracks in walls or paving and hugs the surface, the stems rooting at the nodes as they go. Flowers are minuscule, requiring a hand lens to find them in the leaf axils. Leaves less than 6mm long, bright green with tiny dimples on the surface (under a hand lens).
| |
 |
 |
 |
| |
|
|
|