Lewisia

Key takeaways

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

Reference excerpt

Lewisia is a plant genus, named for the American explorer Meriwether Lewis (1774–1809) who encountered the species in 1806. The native habitat of Lewisia species is rocky ground and cliffs in western North America. Native Americans ate the roots, which have also been used to treat sore throats.

Characteristics Lewisia are succulent perennial plants native to western North American habitats including rocky outcrops from the high elevation alpine to lower elevation chaparral, oak woodlands, and coniferous forests. They produce rosette-shaped flowers in a range of different colours. About half of the species of Lewisia are deciduous, including the original Lewisia rediviva. Lewisia longipetala is the only semi-deciduous species. Some species, such as Lewisia cotyledon, are evergreen.

Taxonomy Meriwether Lewis, of Lewis and Clark fame, is credited with the first discovery by a European or American of Lewisia, which was known to the local Native Americans as bitterroot. Lewis discovered the specimen in 1806 at Lolo Creek, in the mountain range that became known as the Bitterroot Mountains. The plant was given its scientific name, Lewisia rediviva, by Frederick Traugott Pursh.

List of species There are nineteen species and several varieties of Lewisia, including:

Lewisia brachycalyx Engelm. ex A.Gray: United States (California, Arizona, Utah), Mexico (Baja California) Lewisia cantelovii J.T.Howell: US (California, Nevada) Lewisia columbiana (J.T.Howell ex A.Gray) B.L.Rob. Lewisia columbiana var. columbiana: Canada (British Columbia), US (Washington, Oregon) Lewisia columbiana var. rupicola (English) C.L.Hitchc.: Canada (British Columbia), US (Washington, Oregon) Lewisia columbiana var. wallowensis C.L.Hitchc.: US (Idaho, Montana, Oregon) Lewisia congdonii (Rydb.) S.Clay: US (California)

Lewisia cotyledon (S.Watson) B.L.Rob. Lewisia cotyledon var. cotyledon: US (Oregon, California) Lewisia cotyledon var. heckneri (C.V.Morton) Munz: US (California) Lewisia cotyledon var. howellii (S.Watson) Jeps.: US (Oregon, California) Lewisia disepala Rydb.: US (California) Lewisia glandulosa (Rydb.) Dempster: US (California) Lewisia kelloggii K.Brandegee Lewisia kelloggii var. hutchinsonii Dempster: US (California) Lewisia kelloggii var. kelloggii: US (California, Idaho) Lewisia leeana (Porter) B.L.Rob.: US (California, Oregon) Lewisia longipetala (Piper) S.Clay: US (California) Lewisia maguirei A.H.Holmgren: US (Nevada) Lewisia nevadensis (A.Gray) B.L.Rob.: US (Washington, Oregon, California, Nevada, Utah, Colorado, New Mexico) Lewisia oppositifolia (S.Watson) B.L.Rob.: US (Oregon, California) Lewisia pygmaea (A.Gray) B.L.Rob.: Canada (Yukon Territory, British Columbia), US (Alaska, Washington, Oregon, Idaho, Nevada, Utah, Colorado, California, Arizona)

Lewisia rediviva Pursh (Bitterroot; the state flower of Montana) Lewisia rediviva var. minor (Rydb.) Munz: US (California, Nevada, Utah) Lewisia rediviva var. rediviva: Canada (British Columbia), US (Montana, Washington, Oregon, Idaho, Wyoming, Nevada, Utah, Colorado, California, Arizona) Lewisia sacajaweana B.L.Wilson: US (Idaho) Lewisia serrata Heckard & Stebbins: US (California) Lewisia stebbinsii Gankin & W.R.Hildreth: US (California) Lewisia ×whiteae Purdy: US (Oregon) – hybrid of Lewisia leeana and Lewisia cotyledon

Formerly placed here Erocallis triphylla (S.Watson) Rydb. (as Lewisia triphylla (S.Watson) B.L.Rob.)

Distribution and habitat Lewisias are naturally found in western parts of North America. In their native habitat of north-facing cliffs, lewisias are subject to extremes in weather conditions.

Uses All species of Lewisia are edible. Lewisia rediviva has a large edible root and as a result became a food source for Native Americans. The root is peeled before boiling or steaming; cooking the root reduces its bitterness. L. rediviva has also been used for medicinal purposes; chewing the root was used to relieve a sore throat and has also been used to promote milk flow during lactation. For gardening, Lewisia species are usually planted in rockeries, because this mimics their natural habitat. Rockeries also provide the free drainage that lewisias need to prevent their roots rotting. They may also be planted in pots, though they need to be well drained and protected from sustained wet weather.

References

Notes

Bibliography

Illustrations

Worked examples

Example 1 — a first encounter with Lewisia

Start with the simplest possible case. Write down what Lewisia claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, 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 Lewisia 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 Lewisia 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 Lewisia

In research: Lewisia appears in biology 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 Lewisia 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: Lewisia is common in secondary-school and first-year university syllabi. It links to neighbouring topics Caryophyllales genera, Edible plants, Lewisia, so understanding it makes those chapters shorter.
In everyday life: Look for Lewisia 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.

How to study Lewisia in 20 minutes

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

Frequently asked questions

What is Lewisia in simple terms?

Lewisia is a plant genus, named for the American explorer Meriwether Lewis (1774–1809) who encountered the species in 1806. The native habitat of Lewisia species is rocky ground and cliffs in western North America.

Why does Lewisia matter?

Because it connects several biology 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 Lewisia?

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 Lewisia.