Top 10 dicot families

Here Dr M Goes Wild about the TOP TEN DICOT families
Learning to recognise members of these ten families is a good way to start learning plants:

• Click the plant family to see a list of the key characteristics of that family
• Check out the Kew glossary here for definitions of any unfamiliar botanical terms
• Think of examples of each family, we give you one picture to get you started!
• Make sure you are also familiar with the characters which separate superficially similar families, e.g. Ranunculaceae and Rosaceae

NB these notes relate to UK species, species from other lands may vary, e.g. Asteraceae includes many shrubs and trees in other countries of the world.

The largest family of flowering plants
Mainly herbs in UK, leaves alternate and compound or simple, no stipules
Small flowers (florets) clustered into heads (capitula), surrounded by an involucre bracts or phyllaries resembling a calyx
Florets seated on the receptacle, often without calyx but a hairy or scaly pappus
Corolla tubular (disc) or strap shaped (ray) and 5 lobed, 5 stamens joined into a tube
Ovary inferior and 1 celled, fruit an achene.

Large family of trees, shrubs or herbs with alternate leaves often toothed and with stipules
Actinomorphic flowers with hypanthium (extension of the receptacle)
4 or 5 free sepals and petals and many stamens, epicalyx (an extra calyx like whorl) may be present
Ovary inferior or partly inferior (perigynous)
Fruits are achenes, drupes, follicles or pomes.

Mostly annual or perennial herbs with simple, opposite decussate leaves, usually without stipules
Flowers in terminal forked cymes (dichasia) with a central flower in each fork
Flowers actinomorphic with 5 free or fused sepals and usually 4 or 5 free petals, often notched
Superior 1 celled ovary with many ovules and 2-5 styles, and stamens normally equalling or twice the number of petals
Fruit usually many seeded capsule.

Very large family of trees, climbers, shrubs and herbs, many are crop plants
Leaves compound often pinnate with tendrils, stipules present
Flowers in racemes, usually zygomorphic with 5 toothed calyx tube
Flowers with 5 petals often arranged as in the pea flower: 1 top (standard), 2 side (wing) & 2 fused lower (keel)
Usually 10 stamens sometimes fused
Ovary superior and fruit is a pod usually several seeded and dehiscent.

This variable family has been reorganised taxonomically very recently and e.g. Veronicaceae separated out
Mainly herbs, leaves alternate or opposite without stipules, stems round or sometimes square
Flowers usually zygomorphic, 2- lipped or with 4 unequal petals (=Veronicaceae)
4 stamens (2 in Veronicaceae)
Ovary superior and 2 cells joined together with terminal style
Fruit a many seeded capsule with persistent style.

Annual or perennial herbs, alternate leaves, no stipules, often characteristic cabbage or peppery taste, many are crop plants
Flowers in racemes or corymbs usually white or yellow sometimes pink etc.
Flowers actinomorphic with 4 sepals and 4petals arranged in a cross
Usually 2 outer stamens and 4 inner
Superior ovary of 2 carpels, fruit a pod – elongated ‘siliqua’ or flattened ‘silicula’ – which opens by two valves.

Mainly herbs with alternate compound leaves often ternate or pinnate with sheathing petioles, stems hollow, plants often strong smelling, many are food plants
Flowers arranged in compound umbels with bracts at base of primary umbels
Flowers with tiny calyx of 5 teeth or absent, 5 free white or pink or yellow petals often notched and unequal, 5 stamens and 2 styles usually swollen at base (stylopodium)
Ovary inferior of 2 fused carpels which ripens into 2 separating but indehiscent parts – mericarps – often adorned with ridges and wings.

Herbs or dwarf shrubs, many are aromatic and used as herbs
Square stems and opposite decussate leaves without stipules
Flowers in apparently whorled spikes (actually very condensed branched cymes)
Flowers zygomorphic often with 5-lobed calyx tube and 2-lipped corolla tube
2 or 4 stamens and 4-lobed superior ovary with style inserted between the lobes
Fruit is 4, 1-seeded nutlets.

Mainly herbs including aquatics and some shrubs, leaves alternate, palmately lobed or compound without stipules
Flowers actinomorphic with 4 or 5 free sepals and petals with nectaries, sepals may be petaloid or there may be tepals
Numerous free spirally arranged stamens and carpels (check Rosaceae)
Ovary superior, fruit an achene or follicle.

Perennial herbs, leaves simple, entire and usually alternate with characteristic brown or scarious sheathing stipule = ochrea and swollen nodes
Flowers bisexual, white green or pinkish, solitary or arranged in racemes
3-6 tepals free or fused often forming a membrane or wing around the fruit, 6-9 stamens
Ovary superior forming a trigonous nut or achene in fruit.