biology

Ptisana

Ptisana 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 Ptisana rather than just read about it. In short: Ptisana is a genus in the eusporangiate fern family Marattiaceae, comprising species historically treated in the genus Marattia. The establishment of this genus follows the 2008 work by Andrew G.

Key takeaways

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

Reference excerpt

Ptisana is a genus in the eusporangiate fern family Marattiaceae, comprising species historically treated in the genus Marattia. The establishment of this genus follows the 2008 work by Andrew G. Murdock, which supported recognition of this group on the basis of genetic analysis and morphology. Ptisana can be distinguished from Marattia by the presence of distinct sutures at the point of leaflet attachment, deeply cut synangia, and the absence of labiate sporangial apertures. The name Ptisana is derived from the Latin word for pearl barley, an allusion to the shape of the synangia. Ptisana has a palaeotropical distribution, with the westernmost extreme of the range in Ascension Island and extending eastward through tropical Africa, Asia, and Oceania. Ferns in this genus are generally quite large, with fronds often reaching 2–3 meters in length; the one known exception to this is Ptisana rolandi-principis, a critically endangered dwarf species endemic to the Plateau de Dogny in New Caledonia. The basal chromosome number for Ptisana is 2n=78, whereas the one count for Marattia in the strict sense is 2n=80. The type species for the genus is Ptisana salicina, the type specimen of which was collected on Norfolk Island.

Species As of June 2026, World Ferns accepts the following 35 species:

Ptisana acuminata (Willd. ex. Kaulf.) Murdock & Perrie, formerly Ptisana attenutata (Labill.) Murdock – New Caledonia Ptisana africana Christenh. – East Africa Ptisana ambulans Murdock & C.W.Chen – Solomon Islands Ptisana boivinii (Mett. ex Kuhn) Senterre & Rouhan – Madagascar Ptisana boninensis (Nakai) Yonek. – Bonin Islands Ptisana costulisora (Altson) Murdock – New Guinea and nearby islands Ptisana decipiens Murdock & C.W.Chen – Solomon Islands Ptisana fraxinea (Sm.) Murdock – Africa to India, including Indian Ocean islands Ptisana grandifolia (Copel.) Murdock – New Guinea Ptisana howeana (W.R.B. Oliver) Murdock – Lord Howe Island Ptisana koordersii (Alderw.) Christenh. – Sulawesi Ptisana laboudalloniana Senterre & I.Fabre – Seychelles Ptisana melanesica (Kuhn) Murdock – New Guinea and nearby islands Ptisana mertensiana (C.Presl) Murdock – Micronesia Ptisana novoguineensis (Rosenst.) Murdock – New Guinea Ptisana obesa (Christ) Murdock – New Guinea Ptisana odontosora (Christ) Senterre & Rouhan – Guinea Ptisana oreades (Domin) Murdock – northern Australia Ptisana paleolata (Alderw.) Govaerts & Christenh. – Sumatra Ptisana papuana (Alderw.) Murdock & C.W.Chen – Solomon Islands Ptisana pellucida (C.Presl) Murdock – Malaysia, Philippines Ptisana platybasis (Copel.) Murdock – New Guinea Ptisana purpurascens (de Vriese) Murdock – Ascension Island Ptisana rigida (Alderw.) Murdock – New Guinea, Sulawesi Ptisana robusta (Altson) Senterre & I.Fabre – São Tomé Ptisana rolandi-principis (Rosenst.) Christenh. – New Caledonia Ptisana salicifolia (Schrad.) Senterre & Rouhan – South Africa, Zimbabwe, Malawi and Mozambique Ptisana salicina (Sm.) Murdock – king fern; South Pacific islands, including New Guinea Ptisana sambucina (Blume) Murdock – Malesia and Vietnam Ptisana senterreana Christenh. – Cameroon, Gabon, Equatorial Guinea Ptisana smithii (Mett. ex Kuhn) Murdock – Vanuatu, Fiji, Samoa, Tonga Ptisana soluta (Compton) Murdock & Perrie – New Caledonia Ptisana squamosa (Christ) Murdock – New Guinea Ptisana sylvatica (Blume) Murdock – Malesia Ptisana ternatea (de Vriese) Murdock – Moluccas, New Guinea, the Philippines

Phylogeny Phylogeny of Ptisana

References

Illustrations

Worked examples

Example 1 — a first encounter with Ptisana

Start with the simplest possible case. Write down what Ptisana 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 Ptisana 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 Ptisana 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 Ptisana

In research: Ptisana 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 Ptisana 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: Ptisana is common in secondary-school and first-year university syllabi. It links to neighbouring topics Fern genera, Fern stubs, Ptisana, so understanding it makes those chapters shorter.
In everyday life: Look for Ptisana 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 Ptisana in 20 minutes

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

Frequently asked questions

What is Ptisana in simple terms?

Ptisana is a genus in the eusporangiate fern family Marattiaceae, comprising species historically treated in the genus Marattia. The establishment of this genus follows the 2008 work by Andrew G.

Why does Ptisana 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 Ptisana?

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 Ptisana.