science

Zinnia elegans

Zinnia elegans 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 Zinnia elegans rather than just read about it. In short: Zinnia elegans (syn. Zinnia violacea) known as youth-and-age, common zinnia or elegant zinnia, is an annual flowering plant in the family Asteraceae.

Key takeaways

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

Reference excerpt

Zinnia elegans (syn. Zinnia violacea) known as youth-and-age, common zinnia or elegant zinnia, is an annual flowering plant in the family Asteraceae. It is native to Mexico but grown as an ornamental in many places and naturalised in several places, including scattered locations in South and Central America, the West Indies, the United States, Australia, and Italy.

Description The uncultivated plant grows to about 15 cm (5.27 in) in height. It has solitary flower heads about 5 cm (2 in) across. The purple ray florets surround black and yellow discs. The lanceolate leaves are opposite the flower heads. Flowering occurs during the summer months.

History The species was first collected in 1789 at Tixtla, Guerrero, by Sessé and Mociño. It was formally described as Zinnia violacea by Cavanilles in 1791. Jacquin described it again in 1792 as Zinnia elegans, which was the name that Sessé and Moçiño had used in their manuscript of Plantae Novae Hispaniae, which was not published until 1890. The genus was named by Carl von Linné after the German botanist Johann Gottfried Zinn, who described the species now known as Zinnia peruviana in 1757 as Rudbeckia foliis oppositis hirsutis ovato-acutis, calyce imbricatus, radii petalis pistillatis. Linné realised that it was not a Rudbeckia.

Cultivation The garden zinnia was bred via hybridisation from the wild form. Zinnias are popular garden plants with hundreds of cultivars in many flower colours, sizes and forms. There are giant forms with flower heads up to 15 cm (6 in) in diameter. Flower colours range from white and cream to pinks, reds, and purples, to green, yellow, apricot, orange, salmon, and bronze. Some are striped, speckled or bicoloured. There are "pom-pom" forms that resemble dahlias. Sizes range from dwarf varieties of less than 15 cm (6 in) in height to 90 cm (3 ft) tall. The powdery mildew common to zinnias in humid climates is less common in recently developed varieties, which are resistant. The following have won the Royal Horticultural Society's Award of Garden Merit:

Other cultivars include 'Magellan', 'Envy Double', 'Fireworks', 'Blue Point Purple', 'Profusion Cherry', 'Profusion Orange', 'Star Gold', 'Star Orange', and several white-flowered types such as 'Crystal White', 'Purity', and 'Profusion White'. Mixed-colour seed selections are available.

Growth Zinnias grow easily and prefer well-drained, loamy soil and full sun. They grow best in dry, warm, frost-free regions, and many kinds are drought-tolerant. As they do not tolerate freezing temperatures, in temperate zones they must be sown after all danger of frost has passed. Alternatively, they may be sown under cover and carefully transplanted into their final positions when the soil warms up.

Gallery

References

General sources Floridata: Zinnia elegans Plant of the week: Zinnia elegans Garden Guides: Zinnia elegans Wildflower Information: Zinnia elegans Archived 2016-09-16 at the Wayback Machine North Carolina State University: Zinnia elegans Archived 2013-09-03 at the Wayback Machine Flowers of India: Zinnia elegans Kew Plant List The International Plant Names Index

External links Media related to Zinnia elegans at Wikimedia Commons Data related to Zinnia at Wikispecies

Illustrations

Worked examples

Example 1 — a first encounter with Zinnia elegans

Start with the simplest possible case. Write down what Zinnia elegans 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 Zinnia elegans 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 Zinnia elegans 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 Zinnia elegans

In research: Zinnia elegans 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 Zinnia elegans 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: Zinnia elegans is common in secondary-school and first-year university syllabi. It links to neighbouring topics Butterfly food plants, Flora of Mexico, Zinnia, so understanding it makes those chapters shorter.
In everyday life: Look for Zinnia elegans 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.

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How to study Zinnia elegans in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Zinnia elegans 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 Zinnia elegans out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Zinnia elegans in simple terms?

Zinnia elegans (syn. Zinnia violacea) known as youth-and-age, common zinnia or elegant zinnia, is an annual flowering plant in the family Asteraceae.

Why does Zinnia elegans 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 Zinnia elegans?

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 Zinnia elegans.