A short survey of the largest plant families

Almost always harbaceous plants. Leaves are alternate and undivided. Stems and leaves are typically roughly hairy. Flowers in one-sided spikes which are tightly curled at first and gradually unroll. Flowers regular or slightly bilaterally symmetrical. Sepals 5. Petals 5, sometimes (partly) fused. Stamen 5, Superior ovary 1 with 1 or 2 styles. Fruits consisting of 4 little ornamented nuts surrounded by the calyx. Examples of species of Boraginaceae are common vipers bugloss and forget-me-not.

Herbacious plants. The nodes on the stem are swollen. The leaves are almost always opposite. Flowers almost always with stamens and ovaries. Sepals 4 or 5, often joined at the base, sometimes forming a tube. Petals same number as sepals, sometimes small or lacking. Stamens mostly 5 or10 in 1 or 2 circles. 1 superior ovary with 1 to 5 styles. Examples of Caryophyllaceae are Silene vulgaris, bladder campion and Stellaria media, common chickweed.

What looks like a single flower is in fact a number of tiny flowers packed into a flower head or capitulum (plural: capitula), surrounded by one or more wreaths of bracts, specialised leaves. The flowers are of two types: 1. Five petals can be fused to a symmetrical tubular corolla (disk-floret) or 2. The tubular corolla is asymmetrical and the petals are fused on one side into an elongated leaf (ray-floret).
The capitula can consequently be of three types:

• disk-florets only, for example the Thistles;
• ray-florets only, for example the Dandelion;
• disk-florets (yellow) in the middle and ray-florets round the edge, like the Daisy.

The Compositae is a very large family.

Mostly herbs. Flowers with 4 sepals in a cross and 4 petals in a cross, alternating with the petals. 6 stamens of which 4 are long and 2 are short. Ovary superior. Fruits are capsules that open with 2 valves, usually at the top end. Short capsules (length < 3x width) are called silicles, long ones (length > 3x width) are called siliques. Examples of the cabbage family are Biscutella valentina, Buckler mustard, Capsella bursa-pastoris, shepherd’s purse and Lobularia maritima, sweet alyssum.

The stems are usually square in cross section. The leafs are in opposite pairs and are undivided. Flowers are two-sided symmetrical. The petals are fused in an upper lip that is often undivided, sometimes missing,  and an under lip with 3 lobes. Calyx teeth 5-10, often arranged in 2 lips. Stamens 4. Ovary superior. Examples are Thymus vulgaris, common thyme and species of Lamium, deadnettle.

The flowers are usually  large and distinctive. The 5 sepals form a tubular calix with 5 points. Petals 5, a broad upper one, the “standard”, 2 narrow side ones, the “wings” and two lower ones that are (partly) fused, the “keel”. 10 stamens of which at least 9 are bundled. Ovary superior. The seeds are in a pod, usually in the pattern of a garden pea. Examples are species of Trifolium, clover, Lotus corniculatus, common bird’s-foot trefoil and species of Genista, broom.

The Lilies are monocotyledonous plants and have leafs that are linear in shape. The nerves are parallel to the edges. The flowers are large and have 6, most often free, tepals (petal-like flower leaves), 6 stamens, 1 superior ovary with 1 style, sometimes 3. Lilies have bulbs, sometimes rhizomes, and are perennial. Examples are Allium roseum, Rosy garlic, Aphyllanthes monspeliensis, bluegrass lily and species of Asphodelus, asphodel.

Perennials with a fleshy rootstock or a pair of root-tubers. Leaves are simple with parallel veins and a smooth edge. Flowers are bilaterally symmetrical on unbranched terminal spikes. They have 2 whorls of 3 tepals. The upper whorl of 3 sepals usually have the same color as the 2 upper petals of the lower whorl. The 3rd lowest medial petal or “lip” is usually much larger, remarkably shaped with much variety and sometimes spurred behind. The flowers are usually “upside down”. At its base each flower has a small leaf-like bract. The (1-3) stamen, style and stigmas are joined in a single column in the centre.
The flowers are often, but not always, showy. Examples of orchids are Ophrys fusca, sombre bee-orchid, Orchis morio, green-winged orchid and Orchis mascula, early purple orchid.

Mostly herbaceous plants. The leaves are typically alternate. The flowers are often large and regular or bilateral symmetrical. Sepals  3-15, mostly 5. Petals 3 or more. Stamens many. Many superior pistils. Examples are species of Ranunculus, buttercup and Clematis vitalba, old mans beard.

Rosaceae can be trees, shrubs or herbs. They have alternate leaves that can be simple or compound. A leaf usually has a stipule, a smal leaf at the base of the leaf-stalk. The leafs and leaflets are usually oval in shape and have a serrated edge. A flower typically (but not always) has 5 separate petals and sepals, numerous stamens, usually in multiples of 5 and several to numerous superior pistils that are connected at the base in some species. Pistils have 1 style each. Species of apple, plum, rose, strawberry and cherry are examples of Rosaceae.

Mostly herbs, some shrubs. Leafs undivided. Flowers regular or two-sided symmetrical with 2 lips. Calyx fused with 4-5 lobes. Corolla fused into a tube with 4-5 lobes. The 1, 2-locular, ovary is superior, style 1. Stamens 4 or  5. Examples of the figwort family are species of Veronica, speedwell, species of Antirrhinum, snapdragon and Digitalis purpurea, foxglove.

Mostly herbs. The leafs are alternate. They are usually finely divided, up to thrice pinnate. But may be simpel in some species. Most species have an inflorescens that is easily recognisable as an umbrella-shaped umbel. The individual flowers are small and regular but may be bilateral symmetrical at the edge of the umbel, the petals pointing outward larger than the petals pointing inward. Petals 5. Sepals 5, sometimes absent. The pistil consists of two fused carpels, two styles and an inferor ovary. The shape of the frutes may be important for the determination of the species. They consist of two portions underneath the petals when ripe. Examples of the Carrot family are Anthriscus sylvestris, cow parsley, Daucus carota, wild carrot and Scandix pecten-veneris, shepherds needle.