biology

Marietta Hannon Rousseau

Marietta Hannon Rousseau is a biology 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 Marietta Hannon Rousseau rather than just read about it. In short: Marietta Hannon Rousseau, also known as Mariette Rousseau (1850–1926), was a Belgian mycologist and taxonomist specializing in cryptogamic plants and fungi. She published several works on fungi from 1879 to 1905 with Elisa Caroline Bommer, focusing primarily on Belgium.

Key takeaways

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Reference excerpt

Marietta Hannon Rousseau, also known as Mariette Rousseau (1850–1926), was a Belgian mycologist and taxonomist specializing in cryptogamic plants and fungi. She published several works on fungi from 1879 to 1905 with Elisa Caroline Bommer, focusing primarily on Belgium.

Biography

Youth and marriage Marietta was born on 20 March 1850 to Joseph Hannon, a professor of zoology and comparative anatomy at Brussels University. Her father started teaching her about plants when she was young, although the rest of her education is not known. Her knowledge of mycology was self-taught. In 1871 she married Ernest Rousseau, a friend of her fathers and also a professor at the university. They had at least one child, Ernest Rousseau, who was the first president of Les Naturalistes Belges.

Botanical career In 1873 she met Elisa Caroline Bommer, who was also interested in botany. Marietta said of Elisa: "The conformity of our tastes, the similarity of certain aspects of our characters, formed the basis of a complete agreement and a collaboration whose activity could never be slowed down." Bommer's husband Jean-Edouard Bommer suggested the two friends study the local fungi. The two published a series of works in the Bulletin de la Société Royale de Botanique de Belgique from 1879. Together they published a paper on Costa Rican fungi focused on with material collected from 1887 by Henri François Pittier, from which they discovered several new species. They also produced a report in 1905 on the fungi of Antarctica collected by the 1897–99 Belgian expedition led by Adrien de Gerlache de Gomery. Beginning in 1908, Marietta's main focus was on curating the mushroom collection at the Jardin Botanique in Brussels. There, she also put together public exhibits of mushrooms and answered questions about fungi. After Elisa Bommer died in 1910, Marietta was not longer involved in active collecting, but she still led naturalist excursions in Brussels and the surrounding countryside. In 1924 she received the honor of Knight of the Order of Leopold. She was friends with the artist James Ensor with whom she corresponded, and she appeared occasionally as the subject of his paintings and sketches. The genus of Roussoella was named after her by Italian mycologist Pier Andrea Saccardo. The genus Roussoellopsis was also named after her. Her herbarium and types are in the BR Herbarium Catalogue, located at the Meise Botanic Garden. Her other materials can be found at the Plant Pathology Herbarium at Cornell University and the US National Fungus Collection.

Selected list of publications List from Maroske and May:

Bommer E, Rousseau M (1879). Catalogue des champignons observé aux environs de Bruxelles. Bulletin de la Société Royale de Botanique de Belgique18(3): 61–219 [reprinted, TL-2 627]. Bommer E, Rousseau M (1884). Florule mycologique des environs de Bruxelles. Bulletin de la Société Royale de Botanique de Belgique 23(1): 13–365 [reprinted, TL-2 628]. Bommer E, Rousseau M (1886). Contributions à la flore mycologique de Belgique. Bulletin de la Société Royale de Botanique de Belgique 25(1): 13–365. Bommer E, Rousseau M (1887). Contributions à la flore mycologique de Belgique, II. Bulletin de la Société Royale de Botanique de Belgique 26(1): 187–241. Bommer E, Rousseau M (1890). Contributions à la Flore Mycologique de Belgique, III. Bulletin de la Société Royale de Botanique de Belgique 29(1): 205–302. Bommer E, Rousseau M (1896). Primitiae Florae Costaericensis par Th. Durand et H. Pittier. Troisième fasicule. Fungi. Bulletin de la Société Royale de Botanique de Belgique 35: 151–166. Bommer E & Rousseau M (1905). Champignons. Résultats Voyage du S. Y. Belgica en 1897–1898–1899 ... Rapports scientifiques .... 6: 1–15, pl. 1–5.

References

Illustrations

Worked examples

Example 1 — a first encounter with Marietta Hannon Rousseau

Start with the simplest possible case. Write down what Marietta Hannon Rousseau 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 Marietta Hannon Rousseau 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 Marietta Hannon Rousseau 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 Marietta Hannon Rousseau

In research: Marietta Hannon Rousseau 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 Marietta Hannon Rousseau 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: Marietta Hannon Rousseau is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1850 births, 1926 deaths, 19th-century Belgian women scientists, so understanding it makes those chapters shorter.
In everyday life: Look for Marietta Hannon Rousseau 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 Marietta Hannon Rousseau in 20 minutes

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Frequently asked questions

What is Marietta Hannon Rousseau in simple terms?

Why does Marietta Hannon Rousseau 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 Marietta Hannon Rousseau?

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 Marietta Hannon Rousseau.