Mitrastemon

Key takeaways

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

Reference excerpt

Mitrastemon is a genus of two widely disjunct species of parasitic plants. It is the only genus within the family Mitrastemonaceae. Mitrastemon species are root endoparasites, which grow on Fagaceae. It is also a non-photosynthetic plant that parasitizes other plants such as Castanopsis sieboldii.

History The parasitic species, Mitrastemon yamamotoi (Makino) Makino was found in Japan in 1909. It was originally named Mitrastemma yamamotoi Makino by botanist Tomitaro Makino (1862 – 1957), but was later renamed as Mitrastemon yamamotoi in 1911. Then species Mitrastemon matudae was discovered by botanist Eizi Matuda during an expedition to Mt. Ovando (near the town of Escuintla, Chiapas) in the state of Chiapas, Mexico (Matuda, 1947). The species was originally named by a botanist friend of Matuda, Yoshimatsu Yamamoto (1893-1947), in 1925–1926, but then published in 1936. Mitrastemon yamamotoi is a protandrous plant. Its flowers go through a male phase before transforming into their final female form. The flowers of M. yamamotoi attract a variety of insects ranging from wasps to flies and beetles. Among these, beetles are the best pollinators for this plant since their visit to the flower would pick up a large amount of pollen and they would pollinate from each of the flowers that they had already visited. The plant is endemic to tropical and subtropical forest regions such as southeast Asia and Japan.

Taxonomy Originally Mitrastemon was placed within the order Rafflesiales, together with other parasitic plants, but this order was long suspected to be actually polyphyletic. In 2004, the genus was found to be related to Ericales by comparing their mitochondrial DNA. Several orthographic variants of the name Mitrastemon exist, including Mitrastema and Mitrastemma. The correct taxonomic name is Mitrastemon, the use of which was proposed and justified in an article by Reveal and approved by the Nomenclature Committee for Vascular Plants of the International Association for Plant Taxonomy in a subsequent article. The species has a cylindrical body ranging from 3 cm to 7 cm in height with a tuberous base. During an early developmental stage it appears an off-white color; however, once it is dried it becomes a dark brown color (Mir et al., 2016).

Life cycle The plant is observed only during the winter season and it completes its visible life cycle from November to April (Mir et al., 2016). Mitrastemon is completely embedded within the tissues of its host, except during the reproduction stage when above-ground parts emerge from host tissues.

Ecology Unlike other plants, the flowers of this organism change sex from male to female. Various insects are involved in pollination. Mitrastemon yamamotol is mainly pollinated by social wasps, but previously unnoticed pollination are also important, based on visitation frequency and pollen loads. There have been studies of the pollination that suggest that nocturnal visitors, such as crickets and cockroaches, contribute to geitonogamous pollination. Diurnal visitors like social wasps facilitate outcrossing.

Species There are two known species;

Mitrastemon matudae Yamam. Mitrastemon yamamotoi (Makino) Makino

Distribution Mitrastemon yamamotoi is distributed in tropical and subtropical forests of Southeast Asia and Japan. Mitrastemon matudae is distributed from southern Mexico to Colombia.

References

Further reading India Biodiversity Portal. (2019). Mitrastemon yamamotoi Makino. [online] Available at: https://indiabiodiversity.org/species/show/279958 [Accessed 1 Dec. 2019]. Parasiticplants.siu.edu. (2019). Parasitic Plant Connection – Mitrastemonaceae. [online] Available at: https://parasiticplants.siu.edu/Mitrastemonaceae/ [Accessed 1 Dec. 2019]. Upadhaya, Krishna (June 2016). "A Note on Mitrastemon yamamotoi (Mitrastemonaceae): a Root Parasite of Rare Occurrence in North East India". The Journal of Japanese Botany. 91 (3): 179–183. Retrieved 4 December 2019. Matuda, Eizi. "On the genus Mitrastemon." Bulletin of the Torrey Botanical Club (1947): 133-141. Rao, A. S., & Balakrishnan, N. P. (1972). Mitrastemon yalanotoi (Makino) Makino (Rafelesiaceaf)-a Unique Root Parasite New to the Indian Flora. Indian Forester, 98(4), 234-235. Suetsugu, K. (11 August 2018). "Social wasps, crickets and cockroaches contribute to pollination of the holoparasitic plant Mitrastemon yamamotoi (Mitrastemonaceae) in southern Japan". Plant Biology. 21 (1): 176–182. Bibcode:2019PlBio..21..176S. doi:10.1111/plb.12889. hdl:20.500.14094/90005488. PMID 30098096. Leung, Tommy (9 March 2019). "Mitrastemon Yamamotoi". Parasite of the Day blog. Retrieved 7 December 2019. Matuda, Eizi. "On the genus Mitrastemon." Bulletin of the Torrey Botanical Club (1947): 133-141.

Illustrations

Worked examples

Example 1 — a first encounter with Mitrastemon

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

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

How to study Mitrastemon in 20 minutes

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

Frequently asked questions

What is Mitrastemon in simple terms?

Mitrastemon is a genus of two widely disjunct species of parasitic plants. It is the only genus within the family Mitrastemonaceae.

Why does Mitrastemon 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 Mitrastemon?

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 Mitrastemon.