science

Hippeastrinae

Hippeastrinae 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 Hippeastrinae rather than just read about it. In short: Hippeastrinae is a subtribe of plants classified under the tribe Hippeastreae. It belongs to the subfamily Amaryllidoideae of the Amaryllis family (Amaryllidaceae).

Key takeaways

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

Reference excerpt

Hippeastrinae is a subtribe of plants classified under the tribe Hippeastreae. It belongs to the subfamily Amaryllidoideae of the Amaryllis family (Amaryllidaceae).

Description Terrestrial bulbous perennial herbaceous plants, although three species of Hippeastrum are epiphytic. The leaf shape is linear, lorate, or lanceolate (Eithea has oblanceolate-petioled leaves). The leaf growth pattern is annual or persistent, and often histeranthous. Their texture is firm, and they are moderately canaliculated internally. The scape is hollow and the spathe has two bracts which may be fused or free. The inflorescence may have between one and thirteen flowers. The flowers, which may be sessile or pedicellate have a perigone that is actinomorphic to highly zygomorphic, and is tubular, campanulate or infundibulorm in shape. The tepal-tube may vary from obsolete to being more than half the length of the perigone. When a paraperigone is present it consists of basal appendages that are diminutive, membranous, bristle-like, and forming a fimbriate-lacerate or callose ring, partly adnate to the throat of the perigone, surrounding the fascicle of the stamen.

The stamen filaments are filiform and either declinate-ascending or straight and arranged in two to four series (2- or 4-seriate). The stigma is usually either trifid or obscurely trilobed, but some taxa (Famatina herbertiana, and certain Hippeastrum species) have a capitate stigma. The style is either declinate or straight. Chromosome number: 2n = 12–60.

Taxonomy As formulated on morphological grounds alone it included six genera: This included species of medium height and often with many flowers in each inflorescence and inflorescence bracts are different in size and fused basally. The alternative spelling Hippeastrineae was also used by some authors. As reformulated using molecular phylogenetics it included seven to eight genera (Famatina is uncertain). In this redistribution the four species of Famatina were polyphyletic and F. maulensis segregated with Phycella and was consequently placed in Traubiinae, while the remaining three segregated with Rhodophiala and are considered here. However, none of the identified genera were monophyletic. Some subclades were supported, such as the core-Rhodophiala (Rhodophiala excluding R. bifida but including some Famatina). Historical distribution of genera: The genera and (number of species) were as follows:

Eithea (1) (now included in Zephyranthes) Famatina s.s. (extiguished) Habranthus (86) (now included in Zephyranthes) Hippeastrum Rhodophiala (27) (now included in Zephyranthes) Sprekelia (2) (now included in Zephyranthes) Tocantinia (1) (now included in Hippeastrum subgenus Tocantinia) Zephyranthes (107) Formerly included, now subtribe Traubiinae:

Placea Phycella (includes Famatina maulensis) Traubia Following a decision to include Tocantinia within Hippeastrum as a subgenus, a major recircumscription of the Hippeastrae was undertaken in 2019, resulting in recognition of only two genera in Hippeastrinae, most of the remainder being submerged into various subgenera of Zephyranthes;

Hippeastrum Herb. 2 subgenera: Tocantinia (Ravenna) Nic.García (3) Hippeastrum (~100) Zephyranthes Herb. 5 subgenera: Eithea (Ravenna) Nic.García (2) Zephyranthes (~150) Habranthus (Herb.) Nic.García (3) Neorhodophiala Nic.García & Meerow (1) Myostemma (Salisb.) Nic.García (17)

Distribution Mainly subtropical and tropical regions of South America, the Greater Antilles, Mexico, and the southern United States. Core-Rhodophiala species are distributed in Mediterranean Chile, including the lowlands and high-Andes as well as high Andean areas of Argentina, and also the Atacama Desert.

References

Bibliography

Illustrations

Worked examples

Example 1 — a first encounter with Hippeastrinae

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

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

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

Frequently asked questions

What is Hippeastrinae in simple terms?

Hippeastrinae is a subtribe of plants classified under the tribe Hippeastreae. It belongs to the subfamily Amaryllidoideae of the Amaryllis family (Amaryllidaceae).

Why does Hippeastrinae 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 Hippeastrinae?

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 Hippeastrinae.