The Rue Family

Japanese Skimmia Common Rue Mexican Orange-blossom Japanese Skimmia

What are they?

There are no native members of the rue family (Rutaceae) in the UK and it's a rather difficult family to define easily as its members are very varied. The family consists mostly of woody trees or shrubs but also includes some herbaceous species. Most species occur in the tropics or warm-temperate regions of the world. Most notably, many members of this family have glands on the leaves (and sometimes on the flowers) that produce aromatic oils which give off a strong scent if the leaf is crushed. Most of the species also have highly fragrant flowers, making them popular as garden ornamentals.

Where are they found?

These are all non-native plants that are widely grown as garden plants. They may occasionally be found as garden cast-outs, or where planted in amenity landscaping schemes.

Identification

Members of the rue family that have been recorded in the wider countryside in East Anglia are relatively easy to identify from a combination of their flower and leaf detail (and occasionally the fruits). However, it should be borne in mind that other species (particularly of Skimmia) are widely grown and may occur in the future. These can be difficult to tell apart but will be added here if they become established in our region.



Common Rue      Ruta graveolens

Introduced from South-east Europe as a medicinal plant initially but also as a garden ornamental. Recorded as a garden throw-out just a handful of times but occasionally seen in parks and cemeteries. Flowers June to July. Grows to around 50cm in height, becoming wood at the base. Leaves richly blue-green and highly aromatic, but can cause a severe skin reaction from the sap if bruised during hot weather. Seed capsules covered in sunken glands.

Common Rue Common Rue Common Rue
Habit
Flowers
Flowers
Common Rue Common Rue Common Rue
Leaves
Leaf
Seed capsule


Mexican Orange-blossom      Choisya ternata

Introduced from Mexico as a garden ornamental. Recorded as a garden throw-out just a handful of times but widely used in amenity plantings. Flowers mainly in May to June but occasionally at other times also. Grows to around 2m in height, forming a broad mound. Leaves with three leaflets and with a very rich, spicy aroma. Horticultural selection has produced plants with bright yellow foliage (cultivar 'Sundance'), or with very narrow, finger-like leaflets (cultivar 'Aztec Pearl').

Mexican Orange-blossom Mexican Orange-blossom Mexican Orange-blossom Mexican Orange-blossom
Habit
Habit
Flowers
Flowers
Mexican Orange-blossom Mexican Orange-blossom Mexican Orange-blossom
Leaves
cultivar 'Sundance'
cultivar 'Aztec Pearl'


Japanese Skimmia      Skimmia japonica

Introduced from East Asia as a garden ornamental. Recorded as a garden throw-out just a handful of times but widely used in amenity plantings. Flowers March to April. Grows to around 2m in height, forming a broad mound. Leaves simple, thick and leathery, often becoming chlorotic (turning yellow) on chalky soils. Male and female flowers appear on separate bushes in the true species, but some horticultural varieties are hermaphrodite. Male plants are most often the cultivar 'Rubella' which has deep pink flower buds, opening white.

Japanese Skimmia Japanese Skimmia Japanese Skimmia Japanese Skimmia
Habit
Flowers
Flowers
Male flowers
Japanese Skimmia Japanese Skimmia Japanese Skimmia Japanese Skimmia
Female flowers
Leaf
Fruit
Fruit