biology

Hylocereus

Hylocereus 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 Hylocereus rather than just read about it. In short: Hylocereus is a former genus of epiphytic cacti, often referred to as night-blooming cactus (though the term is also used for many other cacti). Several species previously placed in the genus have large edible fruits, which are known as pitayas, pitahayas or dragonfruits.

Key takeaways

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

Reference excerpt

Hylocereus is a former genus of epiphytic cacti, often referred to as night-blooming cactus (though the term is also used for many other cacti). Several species previously placed in the genus have large edible fruits, which are known as pitayas, pitahayas or dragonfruits. In 2017, a molecular phylogenetic study confirmed an earlier finding that the genus Hylocereus was nested within Selenicereus, so all the species of Hylocereus were transferred to Selenicereus.

Description The species previously placed in the genus Hylocereus grow hanging, climbing or epiphytic. They are freely branched, shrubby plants that form aerial roots and become very large with a height of 10 m or more. The green, often glaucous shoots are usually terete or triangular.

Taxonomy In the 1994 classification of the International Cactaceae Systematics Group of the International Organization for Succulent Plant Study, the genus Hylocereus was one of the six genera of the tribe Hylocereeae. A 2011 study of the molecular phylogeny of the Cactaceae concluded that neither the tribe nor the genus was monophyletic (i.e. neither comprised all the descendants of a common ancestor). Two species of Hylocereus formed a clade with two species of Selenicereus, suggesting that the genera were not distinct. This result was confirmed in a larger study in 2017, and all the species of Hylocereus were transferred to Selenicereus.

Species Species that were placed in the genus in 2012 that are now placed in Selenicereus include the following.

Hylocereus calcaratus (F.A.C. Weber) Britton & Rose → Selenicereus calcaratus Hylocereus costaricensis (F.A.C. Weber) Britton & Rose → Selenicereus costaricensis Hylocereus escuintlensis Kimnach → Selenicereus escuintlensis Hylocereus megalanthus (K. Schum. ex Vaupel) Ralf Bauer → Selenicereus megalanthus Hylocereus monacanthus (Lem.) Britton & Rose → Selenicereus monacanthus Hylocereus minutiflorus Britton & Rose → Selenicereus minutiflorus Hylocereus ocamponis (Salm-Dyck) Britton & Rose → Selenicereus ocamponis Hylocereus setaceus (Salm-Dyck ex DC.) Ralf Bauer → Selenicereus setaceus Hylocereus stenopterus (F.A.C. Weber) Britton & Rose → Selenicereus stenopterus Hylocereus triangularis (L.) Britton & Rose → Selenicereus triangularis Hylocereus trigonus (Haw.) Saff. → Selenicereus trigonus Hylocereus undatus (Haw.) Britton & Rose → Selenicereus undatus

See also Epiphyllum – another cactus genus yielding edible fruits

References

CactiGuide: Hylocereus Cactuspedia.info: Hylocereus undatus

Illustrations

Worked examples

Example 1 — a first encounter with Hylocereus

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

In research: Hylocereus 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 Hylocereus 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: Hylocereus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cacti of North America, Historically recognized angiosperm genera, Night-blooming plants, so understanding it makes those chapters shorter.
In everyday life: Look for Hylocereus 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 Hylocereus in 20 minutes

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

Frequently asked questions

What is Hylocereus in simple terms?

Why does Hylocereus 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 Hylocereus?

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 Hylocereus.