science

Thelypteridaceae

Thelypteridaceae 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 Thelypteridaceae rather than just read about it. In short: Thelypteridaceae is a family of about 900 species of ferns in the order Polypodiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is placed in the suborder Aspleniineae.

Key takeaways

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

Reference excerpt

Thelypteridaceae is a family of about 900 species of ferns in the order Polypodiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is placed in the suborder Aspleniineae. Alternatively, the family may be submerged in a very broadly defined family Aspleniaceae as the subfamily Thelypteridoideae. The ferns are terrestrial, with the exception of a few which are lithophytes (grow on rocks). The bulk of the species are tropical, although there are a number of temperate species. These ferns typically have creeping rhizomes. The fronds are simply pinnate to pinnate-pinnatifid. There is either no frond dimorphism or only mild dimorphism, either open venation or very simple anastomosing. The sori are mostly reniform in shape and have indusia, except for the Phegopteris group.

Classification During the early and mid 1900's all thelypterioid ferns were included in the genus Dryopteris because of the sorus shape. However, there are a great many differences between the groups, and these plants are now segregated in their own family. Genetic evidence shows that the family is clearly monophyletic.

Phylogenetic relationships The following cladogram for the suborder Aspleniineae (as eupolypods II), based on Lehtonen (2011), and Rothfels & al. (2012), shows a likely phylogenetic relationship between the Thelypteridaceae and the other families of the clade.

Genera The family can be divided into two major clades, which the Pteridophyte Phylogeny Group classification of 2016 (PPG I) recognizes as two subfamilies, Phegopteridoideae and Thelypteroideae. Their division into genera has been described as "highly controversial and fluctuating". The family includes several complexes of species that are difficult to distinguish, and seem to represent a remarkable evolutionary radiation. Some researchers include the entire family Thelypteridaceae in the genus Thelypteris; others divide the family into as many as 30 genera. An intermediate position is to place the bulk in Thelypteris (which can then be divided into subgenera and sections corresponding to the genera of other authors) but to separate out Phegopteris and Macrothelypteris. Another choice is to divide the family into a half a dozen or so genera.

The Pteridophyte Phylogeny Group classification of 2016 (PPG I) accepts 30 genera:

Subfamily Phegopteridoideae Salino, A.R.Sm. & T.E.Almeid Macrothelypteris (H.Ito) Ching Phegopteris (C.Presl) Fée Pseudophegopteris Ching Subfamily Thelypteridoideae C.F.Reed Steiropteris (C.Chr.) Pic.Serm. Tribe Thelypterideae Ching 1963 Thelypteris Schmidel Tribe Amauropelteae Wei, Liu & Liu Amauropelta Kunze Coryphopteris Holttum Metathelypteris (H.Ito) Ching Tribe Oreopterideae Wei, Liu & Liu Oreopteris Holub Tribe Leptogrammeae Todaro 1866 Cyclogramma Tagawa Leptogramma Smith Stegnogramma Blume Tribe Meniscieae Fée 1850-1852 ex Pfeiffer 1873 Subtribe Goniopteridinae Ching 1963 Goniopteris C.Presl Subtribe Menisciinae Payer 1850 Ampelopteris Kunze Cyclosorus Link Meniscium Schreb. Mesophlebion Holttum Subtribe Pseudocyclosorinae Ching 1963 Abacopteris Fée Amblovenatum J.P.Roux Chingia Holttum Christella H.Lév. Glaphyropteridopsis Ching Grypothrix (Holttum 1971) Fawcett & Smith Menisciopsis (Holttum 1982) Fawcett & Smith Menisorus Alston Mesopteris Ching Pakau Fawcett & Smith Parathelypteris (H.Ito) Ching Pelazoneuron (Holttum 1974) Smith & Fawcett Plesioneuron (Holttum) Holttum Pneumatopteris Nakai Pronephrium C.Presl [Nannothelypteris Holttum] Pseudocyclosorus Ching Reholttumia Fawcett & Smith Sphaerostephanos J.Sm. Strophocaulon Fawcett & Smith Trigonospora Holttum Some species of Pronephrium were split off into other genera in 2021 as a result of a phylogenetic study of the family Thelypteridaceae:

Abacopteris Fée Grypothrix (Holttum) S.E.Fawc. & A.R.Sm. Menisciopsis (Holttum) S.E.Fawc. & A.R.Sm The extinct genus Holttumopteris from the Cenomanian aged Burmese amber has been suggested to have affinities with the family, but several important diagnostic characters are not preserved.

References

Illustrations

Worked examples

Example 1 — a first encounter with Thelypteridaceae

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

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

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

Frequently asked questions

What is Thelypteridaceae in simple terms?

Thelypteridaceae is a family of about 900 species of ferns in the order Polypodiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is placed in the suborder Aspleniineae.

Why does Thelypteridaceae 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 Thelypteridaceae?

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 Thelypteridaceae.