science

Asterids

Asterids is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Asterids rather than just read about it. In short: Asterids are a large clade (monophyletic group) of flowering plants, composed of 17 orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked clades lamiids (8 orders) and campanulids (7 orders), and the single orders Cornales and Ericales.

Key takeaways

Asterids belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Asterids to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Asterids from memory before moving on to harder problems.

Reference excerpt

Asterids are a large clade (monophyletic group) of flowering plants, composed of 17 orders and more than 80,000 species, about a third of the total flowering plant species. The asterids are divided into the unranked clades lamiids (8 orders) and campanulids (7 orders), and the single orders Cornales and Ericales. Well-known asterids include dogwoods and hydrangeas (order Cornales), tea, blueberries, cranberries, kiwifruit, Brazil nuts, argan, sapote, and azaleas (order Ericales), sunflowers, lettuce, common daisy, yacon, carrots, celery, parsley, parsnips, ginseng, ivies, holly, honeysuckle, elder, and valerian (clade campanulids), borage, forget-me-nots, comfrey, coffee, frangipani, gentian, pong-pong, oleander, periwinkle, basil, mint, rosemary, sage, oregano, thyme, lavender, wild dagga, olives, ash, teak, foxgloves, lilac, jasmine, snapdragons, African violets, butterfly bushes, sesame, psyllium, potatoes, eggplants, tomatoes, chilli peppers, tobacco, petunias, morning glory, and sweet potato (clade lamiids). Most of the taxa belonging to this clade had been referred to as Asteridae in the Cronquist system (1981) and as Sympetalae in earlier systems. The name asterids (not necessarily capitalised) resembles the earlier botanical name but is intended to be the name of a clade rather than a formal ranked name, in the sense of the ICBN.

History Genetic analysis carried out after APG II maintains that the sister to all other asterids are the Cornales. A second order that split from the base of the asterids are the Ericales. The remaining orders cluster into two clades, the lamiids and the campanulids. The structure of both of these clades has changed in APG III. In the APG III system, the following clades were renamed:

euasterids I → lamiids euasterids II → campanulids

Phylogeny The phylogenetic tree presented hereinafter has been proposed by the APG IV project.

Subdivision

Lamiids The lamiid subclade consists of about 40,000 species and account for about 15% of angiosperm diversity, characterized in general by superior ovaries and corollas with any fusion of the petals (sympetaly) occurring late in the process of development. The major part of lamiid diversity occurs in the group of five orders from Boraginales to Solanales, referred to informally as "core lamiids" (sometimes called Laminae). The remainder of the lamiids are referred to as "basal lamiids", in which Garryales is the sister group to the core lamiids. It has been suggested that the core lamiids radiated from an ancestral line of tropical trees in which the flowers were inconspicuous and the fruit large, drupaceous and often single-seeded.

See also List of lamiid families List of basal asterid families

References

Bibliography

External links Media related to Asterids at Wikimedia Commons Asterids in Stevens, P. F. (2001 onwards). Angiosperm Phylogeny Website. Version 7, May 2006.

Illustrations

Worked examples

Example 1 — a first encounter with Asterids

Start with the simplest possible case. Write down what Asterids claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Asterids before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Asterids ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Asterids

In research: Asterids appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Asterids in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Asterids is common in secondary-school and first-year university syllabi. It links to neighbouring topics Asterids, Plant unranked clades, Superasterids, so understanding it makes those chapters shorter.
In everyday life: Look for Asterids outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Asterids in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Asterids means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Asterids out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Asterids in simple terms?

Why does Asterids matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Asterids?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Asterids.