For over 250 years flowering plants were arranged in various classification systems according to their morphology and biochemistry. Botanists and biologists from around the world supported and used different systems (e.g. de Candolle, Lindley, Bentham & Hooker, Engler, Hutchinson, Takhtajan, Cronquist, Dahlgren) which caused some confusion and even more debate. In the last twenty years the classification of plants has changed dramatically with the accumulation of molecular data that are unravelling the true evolutionary relationships of plants.

Plants have adapted over millions of years to different pollination syndromes and/or challenging environments (e.g. arid, saline) and this has resulted in some...

Flowers are needed for flowering plant identification though when there are only fruits present it is still possible but becomes more difficult. In most cases a combination of vegetative and reproductive parts are needed and in some cases a combination of both floral and fruit characters. Plants without a perianth (i.e. both sepals and petals absent) and parasitic plants have evolved several times and are scattered across the following six higher groups. For these plants it is best to try and identify by a process of elimination from the list of families with diagnostic characters pages....

A list of families with useful diagnostic (‘spot’) characters that are constant or with notable members. It is not a comprehensive list but aims to act as a guide and should help aid identification by a process of elimination....

Basal angiosperms are the earliest diverging lineages of flowering plants and the most commonly encountered are the laurels, magnolias and waterlilies.

These lineages often exhibit ‘primitive’ or ancestral characters such as an open flower organisation and little distinction between the sepals and petals. They generally lack ‘advanced’ or derived characters such as fused petals and zygomorphy.

Basal angiosperms are usually woody plants with notable herbaceous exceptions, such as those in the Piperales and Nymphaeales. The leaves are usually simple and often aromatic containing ethereal oils. Stipules are always or sometimes present in the following families: Austrobaileyaceae?, Chloranthaceae, Magnoliaceae, Nymphaeaceae and...

Monocots are a diverse and distinctive group that are relatively easy to identify in the field. They include well-known groups such as arums, bananas, daffodils, gingers, grasses, lilies, onions, orchids, palms, rushes, sedges and yams. They comprise about 22% of all angiosperms.

Monocots can be identified by a combination of several characters rather than just one due to several exceptions. There is a single cotyledon or one seedling leaf which give the group the name monocotyledons and shortly referred to as monocots. This is in contrast to two cotyledons in most other angiosperms which were traditionally referred to as dicotyledons...

These eight lineages, consisting of six orders and two unplaced families, form a morphological transition grade between the basal angiosperms and the core eudicots. They exhibiting a mixture of primitive (or ancestral; e.g. free and many floral parts) and advanced (or derived; e.g. fused and fewer floral parts) characters, on the same or different individual(s).

Stipules are present in the following families: Berberidaceae, Dilleniaceae (stipule-like structures), Gunneraceae, Myrothamnaceae, Nelumbonaceae, Platanaceae, Ranunculaceae (few) and Trochodendraceae.

The unplaced sabiaceae have 5-merous flowers with sepals, petals and stamens all arranged in opposite whorls. The Dilleniaceae are the other unplaced family and are characterised...

Rosids are a diverse group usually with free petals, sometimes a hypanthium and/or nectar disk present and stamens usually equal or more than the petals. They comprise about 25% of all angiosperms diversity with 17 orders and 176 families. Rosid orders are often morphologically diverse but most large families usually have distinctive characters. A few families have a fused perianth which could be confused with many asterids, notably Cucurbitaceae and Thymelaeaceae....

Three lineages primarily dominated by hemiparasitic plants with chlorophyll and plants that exhibit adaptations to stressful environments. Commonly encountered plants in these lineages include cacti, mistletoes, sundews, bougainvillea and carnations.

Caryophyllales are dominated by succulent, carnivorous, xerophytic and halophytic plants, petals are commonly absent but if they are deemed present are often of staminodal origin. santalales consists mainly of root-or stem-parasites with chlorophyll, stipules are absent and the sepals are commonly reduced to absent. Berberidopsidales consists of three genera and four species and have spirally arranged flowers, stout stamen filaments, fleshy fruits and lack stipules.

Stipules are sometimes present in...

Asterids comprise about a quarter of angiosperm diversity and can be identified by the usually fused petals and the number of stamens usually equal or less than the petal number. However, it should be noted several families do have free petals and these are listed below.

Families always or sometimes with free petals: Actinidiaceae, Aquifoliaceae, Araliaceae, Bruniaceae, Curtisiaceae, Cornaceae, Escallionaceae, Griseliniaceae, Icacinaceae, Lecythidaceae, Marcgraviaceae, Metteniusaceae, Montiniaceae, Paracryphiaceae, Primulaceae, Sarraceniaceae, Sladeniaceae, Stemonuraceae, Tetrameristaceae and Vahliaceae.

Families always or often with >15 stamens: Actinidiaceae, Cornaceae, Ebenaceae, Fouquieriaceae, Hydrangeaceae, Lecythidaceae, Loasaceae, Marcgraviaceae, Mitrastemonaceae, Sarraceniaceae and Theaceae.

Families with stipules: Actinidiaceae, Adoxaceae, Aquifoliaceae, Apiaceae,...