What is a rhizome?


Rhizome Definition

A rhizome (also known as rootstocks) is a type of plant stem situated either at the soil surface or underground that contains nodes from which roots and shoots originate (shown below). Rhizomes are unique in that they grow perpendicular, permitting new shoots to grow up out of the ground. When separated, each piece of a rhizome is capable of producing a new plant.

Rhizome Function

The primary function of the rhizome is the storage of nutrients, including carbohydrates and proteins, until the plant requires them for the growth of new shoots or to survive the winter in a process termed vegetative reproduction. Farmers use vegetative reproduction to laterally propagate plants such as hops, ginger and various grass species. Some rhizomes are also consumed or used as a seasoning, including ginger and turmeric.

Rhizome Examples

Underground Rhizomes

By far the most dominant type of rhizome is the underground rhizome (pictured below), which is situated underground and includes ginger, hops, poison oak, grass species, and bamboo. Many of these plants have rhizomes that are consumed by humans (e.g., ginger).

Above-ground Rhizomes

While most rhizomes are situated underground, some plants have rhizomes that grow at the soil level or above (shown below). Examples of these plant species include ferns and irises.

Multi-layered Rhizomes

The majority of rhizomes occur as a single layer from which shoots and roots originate. However, there are some plant species which form multiple layers in a complex network (e.g., Giant Horsetails ).


1. True or False, rhizomes are always found underground.

Answer to Question #1 False. While most rhizomes form underground, there are some species of plants with rhizomes at the soil surface or above.

2. Which of the following statements is TRUE regarding the function of the rhizome:
A. The rhizome is an enzyme found in plants
B. The function of the rhizome is to store nutrients
C. The function of the rhizome is to provide a defense against pathogens
D. None of the above are true

Answer to Question #2 B is correct. The rhizome functions to store nutrients in preparation for winter or the growth of new shoots/roots.

All About Rhizomes

Angus Stewart

ANGUS STEWART: Plants are made up of a whole lot of different parts. Flowers, roots, leaves. But there’s one part that’s absolutely vital to their survival – and that’s the stem.

Stems hold plants erect so they can reach upwards for air and sunlight. They transplant food and nutrients to other parts of the plant, and they also store nutrients and produce new leaves and shoots from small bumps of tissue called nodes.

Nodes on above ground stems are very obvious. You can see the new leaves and shoots emerging. But today, I want to show you some plants whose structure includes cleverly modified stems – ones that grow horizontally and under the ground.

These horizontal, subterranean stems are called rhizomes. You find them on edible plants like asparagus and ginger, grassy plants such as bamboo and on a range of ornamentals, including Dianella and Lomandra.

There are two basic types of rhizome – running and compact and the classification is based on the distance between the nodes. So you can see those two bumps there. They’re the nodes and the distance in between is called an internode. When it’s long, you have a running type of rhizome, when it’s compact, that internode is very short. Now imagine this stem as a telescope that we can concertina down. If we were to compress that right down, we end up with a compact type of rhizome, like this ornamental ginger. You can see how this gives a clumping habit and the basic thing there is that it won’t escape that clump and spread to other parts of your garden.

Coming back to the bamboo, you can see how the running rhizome enables an original clump to spread to other parts of the garden and from there, it just keeps going exponentially. So my advice when it comes to choosing rhizomatous plants is simply avoid these running types. That way you won’t be introducing any aggressive new weeds into your garden.

The good news for the home gardener is that the survivability’s that make rhizomatous plants so tough also make them very easy to propagate. The way to propagate rhizomatous plants is by division. The first step is to remove all the dead and dying foliage and old flower stems and I like to reduce the foliage by a half because that’ll take a lot of the water stress off the new division. We’re then ready to take the plant out of the pot. They can be a bit tricky to get out sometimes, but you’ve just got to be tenacious. So a serrated edged knife is the perfect tool for cutting right through the middle of the plant before you divide it up further. So you need to be a bit ‘bullish’ about this. Just get in and you might damage the odd shoot, but it really doesn’t matter. Just got to get all the way through the plant.

Ok. We’ve now got the plant ready for the next stage. You can actually see the structure of the rhizomes. All that storage of water and nutrients is what makes these plants so easy to propagate. They’re well able to resist the stress of this rather drastic operation.

If you’re going straight back into the garden, it’s a good idea to keep the sections quite large. So that bit we’ll put aside. This one I want to divide into three smaller sections to go back into pots.

When you’re potting rhizomes, it’s really important to have a well drained mix so that you avoid them rotting out. Also ensure that the rhizome stays at the same level it was in the original pot and water them very sparingly at first, because you want to wait for some new growth. Once you see roots coming out the bottom of the pot and a little bit of top growth, you can increase the watering.

So the bottom line with rhizomes is to avoid those running types so you don’t create any weed problems, but apart from that, they’re functional and beautiful plants. And in these dry times, they’re such great survivors that they’re a great addition to any garden.

STEPHEN RYAN: Frost can play merry hell with your garden, but don’t despair. There are lots of things you can do and here’s Tino to show us a few tricks of the trade.



A bulb is a short stem with fleshy leaves or leaf bases. The leaves often function as food storage organs during dormancy.

Leaf Base

A bulb’s leaf bases generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions. The leaf bases may resemble scales, or they may overlap and surround the center of the bulb as with the onion. A modified stem forms the base of the bulb, and plant growth occurs from this basal plate. Roots emerge from the underside of the base, and new stems and leaves from the upper side. (Wikipedia)


A corm (or bulbo-tuber, bulbotuber) is a short, vertical, swollen underground plant stem that serves as a storage organ used by some plants to survive winter or other adverse conditions such as summer drought and heat (estivation). A corm consists of one or more internodes with at least one growing point, with protective leaves modified into skins or tunics. The thin tunic leaves are dry papery, dead petiole sheaths, formed from the leaves produced the year before, which act as a covering that protects the corm from insects and water loss. Internally a corm is mostly made of starch-containing parenchyma cells above a circular basal node that grows roots. (Wikipedia)


A rhizome (from Ancient Greek: rhízōma “mass of roots”, from rhizóō “cause to strike root”) is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes. Rhizomes may also be referred to as creeping rootstalks or rootstocks. Some plants have rhizomes that grow above ground or that lie at the soil surface, including some Iris species, and ferns, whose spreading stems are rhizomes. (Wikipedia)


A stem tuber forms from thickened rhizomes or stolons. The tops or sides of the tuber produce shoots that grow into typical stems and leaves and the under sides produce roots. They tend to form at the sides of the parent plant and are most often located near the soil surface. The below-ground stem tuber is normally a short-lived storage and regenerative organ developing from a shoot that branches off a mature plant. The offspring or new tubers, are attached to a parent tuber or form at the end of a hypogeogenous rhizome. In the fall the plant dies except for the new offspring stem tubers which have one dominant bud, which in spring regrows a new shoot producing stems and leaves, in summer the tubers decay and new tubers begin to grow. Some plants also form smaller tubers and/or tubercles which act like seeds, producing small plants that resemble (in morphology and size) seedlings. Some stem tubers are long lived such as those of tuberous begonia but many tuberous plants have tubers that survive only until the plants have fully leafed out, at which point the tuber is reduced to a shriveled up husk.

Plant Propagation Technique

A Rhizome is actually a stem of a plant, most commonly growing underground, that produces roots and stem shoots along its length from nodes. They are also known as rootstocks and creeping rootstalks.

When cut into pieces, each piece of the Rhizome can potentially grow into a new plant through a process known as vegetative reproduction. Many plants are cloned in this manner, including asparagus, bamboo, ginger, hops, Canna lilies, even the Venus Flytrap.

Rhizomes have compact internodal spacing which produce roots from the bottom of the nodes and stem shoots from the top.

A few plants have Rhizomes that grow along the top of the ground, including ferns and some species of Iris.

In some cases, Rhizomes are considered a nuisance, as they can cause a plant to spread beyond its intended borders. The implentation of a Rhizome barrier can keep plants that reproduce through Rhizomes from spreading.

Often confused with a Rhizome is the Stolon, and while similar, a stolon sprouts from and existing plant stem, has much wider internodal spacing, and generates its new shoots at the terminating end. Strawberry plants are an example of a plant that produces Stolons, as opposed to true Rhizomes.

Propagation by Rhizomes Articles

Propagating Bamboo From Rhizomes

How To Plant Iris Rhizomes In Your Garden
by Mr. Brown Thumb

Hops TV, Episode 1: Planting Hops
by HopsDirect.com

Planting Rhizomes and Tubers

With the overwhelming feeling that we’re soon to exit winter, we begin to contemplate what will make a grand entrance into the spring garden. On top of the list are rhizomes and tubers, that give us the first planting opportunity of the encroaching season. While they now lie in their dormant state, they will soon unleash their growing energy and provide the first true signs of spring growth. So it’s worth reviewing how best to plant and then harvest these varieties.

Rhizomes Asparagus, Ginger, Turmeric, Galangal, Horseradish, Rhubarb, Hops, Mint (yes, mint!)

Plants like ginger, asparagus and rhubarb are best grown from rhizomes. which are technically underground stem systems. They invade areas around the parent plant to extend horizontally and produce above ground shoots, in this way, new “clone” plants are created. In the case of ginger and turmeric, we eat the underground rhizome itself (though the tops are edible too), whereas the above ground shoots are what interest us when it comes to asparagus and rhubarb. With hops – another famous rhizome – its flower cone is the object of our desire.

Rhizomes are often called “creeping rootstalks” and by dividing them it is possible to grow new plants from each piece. In nature, a rhizomes are known to survive fire and drought, laying dormant underground until good growing conditions are available. As a result, they are very hearty and can be transported easily without water or soil. Many people order seed rhizomes online or buy them from a local nursery to ensure that they don’t contain any disease/pesticides/herbicides. However, it is also possible to plant a piece of (organic) ginger from the grocery store- but success will vary.

It may surprise you but mint is also a form of rhizome and can be easily planted from reserved root stock; perhaps even from your flailing pot bound mint.

How to plant:

1. Soak rhizome for a few hours in water or compost tea.

2. In well draining soil, dig a shallow hole or trench and plant rhizome horizontally with any shoots or pointing upward.

3. Cover rhizome with about 3cm of soil.

4. Water in thoroughly. Continue to water every second or third day, as overwatering can cause rot.

Edible rhizomes are slow growing at first, so don’t expect any visible growth for about a month.


Rhizomes are typically long term investments and will grow in size, and therefore productivity, with age. Asparagus is, indeed one of these long term investments, particularly in a small space garden, but that’s not to say it isn’t worth your effort and a piece of your precious real estate. Rather than the traditional wait for mature asparagus to begin shooting, we now favour taking whatever we can get. The finer, adolescent shoots, while being less substantial offer unparalleled culinary prowess.

Rhubarb plants will produce for around 10 years, but every few years the stems will become visibly crowded and thin, necessitating that you divide the root bulb (best to do this in late autumn). Regift your divided rhubarb to become the most popular gardener on the block or to expand you personal rhubarb empire.

Tubers Potato, Sweet potato, Yam, Cassava, Jerusalem artichoke

“It’s not a tuber!” shouted Arnold Schwarzenegger in the perennial classic Kindergarten Cop. At least that’s what we heard. Potatoes, on the other hand, are tubers. As are yams and the poorly named Jerusalem artichoke.

Tubers are neither roots nor rhizomes, but are often found in their company and are, in fact, a growth of reserve nutrients. Like an underground doomsday bunker, tubers store plant energy for an uncertain future. They are rich in simple carbohydrates (starches) and sugars, which is what makes them so delicious. It is this stored energy that gives them the potential to grow a new plant at a moment’s notice or lay dormant until conditions improve.

Anyone that has left a potato long enough has seen it start to produce sprouts. Seed tubers from a nursery are often well sprouted and will not carry any soil borne disease, which is not the case for market bought varieties. For those with small spaces, we recommend planting tubers in a felt pot or other container so that growth cannot invade the rest of your garden. Keeping tubers in a separate container also guarantees that you won’t miss any produce when it comes to harvest time.

How to plant:

1. Select a collection of your favourite seed tubers.

2. Larger pieces can be cut in half, but make sure that there are a few sprouting eyelits on each piece.

3. Dig a 15 cm trench in nutrient rich and well draining soil, space seeds about 25cm apart.

4. Cover over with soil and water in


Tubers grown in the garden bed are best harvested with a garden fork, which lifts away much of the plant while allowing excess soil to fall through its tines. When harvesting, sink the fork into the ground – giving a fairly wide berth from where you expect the first tuber (don’t want to spear it!) – to lift the earth and reveal the tubers growing beneath.

When planting in a felt pot or other container, it can simply be dumped upside down to reveal all of the contents inside. This allows growers to quickly sift through the soil with their hands and ensures that no tubers will be missed.

Once harvested leave dirt on them and store in a cool, dark place. Decent ventilation is important because tubers will continue to breath and repair bruises/blemishes for a couple of months after harvesting. Keep away from sunlight.

A. Let’s begin by understanding propagation is a term for reproducing a plant from seed or vegetation. Vegetative propagation can be done by division, cutting or layering. The plant materials you are interested in can all be propagated by division. In our area division will usually be done in the Fall or the season opposite the bloom cycle of the plant.

Stolons are stems that creep horizontally above ground. These stems or runners contain nodes or joints. Nodes are where the new roots and plants develop. Plants such as strawberry and spider plant have stolons. Division can be made by separating sections containing a node and then planting the section.

Rhizomes, tubers, bulbs and corms are actually underground stems, not roots. These underground stems are storage containers for the plant.

Rhizomes are stems that grow horizontally, but rhizomes grow underground and generally have a thickened stem that is used for storage. Rhizomes have eyes or buds that appear along the top and sides, which grow upward to produce new stems and foliage. Some rhizomes are fleshy like the iris and some are slender and elongated with internodes as in Bermudagrass. To propagate, cut into sections containing at least one eye and plant.

Tubers are thickened terminal portions of the stem. They are usually fat, round and knobby and do not grow horizontally. They have eyes or buds that create new shoots which will become new plants. Tubers can be cut into sections containing at least one eye per section. Caladiums, cyclamen and tuberous begonia are all tuber plants.

A bulb actually contains the embryo of a new plant. If a lengthwise cross section cut were made you would see a tiny stem and flower as well as fleshy modified leaves called scales encircling the embryo. These scales serve as food reserves for the tiny plant. There are two types of bulbs. One is like an onion with an onion-like skin called a tunic, as in tulip. The other has overlapping scales like garlic and no outer skin, such as lilies. Propagate by dividing bulbils (lateral buds on the base plate) off bulb and replanting or storing until the next planting season.

Corms are similar to bulbs but do not have fleshy scales. Corms are either rounded or slightly flattened at the top and have dry scale-like scales held together at the basal plate where the roots grow. The parent corm dies back but produces cormels or cormlets from buds on the top or side of the original corm. Large new corms may flower the following year, but the smaller cormels may take several years to bloom. Cormels can be divided from the shriveled parent corm and planted separately. Gladiolus and crocus are examples of corm plants.

Good Luck!

What Is A Rhizome: Learn About Rhizome Plant Facts

We often refer to the underground part of a plant as its “roots,” but sometimes that’s not technically correct. There are several parts of a plant that can grow underground, depending both on the type of plant and the part you’re looking at. One common underground plant part, not to be mistaken for a root, is the rhizome. Keep reading to learn more rhizome information and what makes a rhizome.

Rhizome Plant Facts

What is a rhizome? Technically, a rhizome is a stem that grows underground. It usually grows horizontally, just below the soil’s surface. Since it’s a stem, it has nodes and is able to put out other stems, usually straight up and above ground. This means a patch of what looks like several individual plants grouped near each other may actually all be shoots of the same plant, put up by the same rhizome.

Rhizomes are also used by the plant to store energy, since they are thicker than above ground stems and under the soil where they are safe from freezing temperatures. Many cold weather perennials have rhizomes, and they use this energy storage to survive underground through the winter.

Because they spread stealthily and are hard to kill, rhizomes can be the source of some serious weed problems. Some plants will sprout from even a tiny fragment of rhizome, meaning that eradicating certain weeds can be very difficult. By the same token, it can be very helpful if you’re looking for a lasting and spreading groundcover in the garden.

What Plants Have Rhizomes?

Many plants, both wanted and unwanted, have rhizomes. Some of the most common garden plants with rhizomes include:

  • Hops
  • Ginger
  • Turmeric
  • Iris

Sometimes pretty groundcovers and flowers that are commonly planted can get out of hand with their spreading rhizomes, making their vigorous growth more weedy in nature than intended. These can include:

  • Pachysandra
  • Lily of the valley
  • Bamboo
  • Tansy

And then there are pesky weeds that crop up into the landscape by way of quick spreading rhizomes such as poison ivy and Virginia creeper.

What’s the difference between a root and a rhizome?

Posted on: February 7, 2017

When you look at a plant in the ground, some parts are easy to spot. Most kids could do it. Hey, there’s the flower. That there is a leaf. Done and done. But below ground, things get a bit more confusing. There are roots, sure, but rhizomes too. And some plants like tubers and bulbs exist almost entirely underground. So what are all these things?

Well, let’s break it down.

Meet the root

Roots are the most familiar plant part here. They extend down into the soil like an anchor. They’re generally vertical and they often look like hairs. (Roots even look fibrous when you look at them under the microscope scope.) They pull moisture and nutrients up from their tips to hydrate the plant above. And they even digest nutrients from the dirt.

At our organic farm in Josephine County, Oregon, we grow a ton of herbs for their roots. This includes: Angelica, Burdock, Comfrey, Culver’s Root, Echinacea, Elecampane, Horseradish, Marshmallow and Valerian.

Rhizomes are different

Rhizomes are underground stems. They generally grow horizontal, perpendicular to gravity. Often, rhizomes run just under the soil, sprouting roots and shooting up new vertical stems as they go. Plants use them to store energy. So they can be fatter than how you’d normally think of a stem.

Nearly all the perennials that grow in northern climates like at our Oregon farm go dormant during the winter. The rhizome helps them survive until spring.

Rhizomes are how a ton of perennials spread. The mint family especially. Sometimes we’ll plant something from the mint family like, Skullcap, in one plot. Then we come back the next spring and find the plant has spread to soil one or two plots away.

Rhizomes have so much energy, they’re great for propagating. That means we can dig up one plant’s rhizome. Cut it up. Replant. And get as many as 10-12 plants growing. Bloodroot and Black Cohosh are great for this sort of replanting.

So what about tubers?

Now we’re going from plant parts to types of plants. Tubers are oblong underground growths off the stem. They have tiny leaves with buds or eyes. They’re generally more swollen and fat than a rhizome. Think of a potato. Potatoes are tubers. We don’t grow any tubers as herbs at Herb Pharm.

So then bulbs. What are they?

Like tubers, bulbs are underground and connected to the stem. Except bulbs are buds and they’re more round and globular. They can have leaves at the top poking out above ground and roots shooting off below. Think of Garlic or an onion. Those are bulbs.

So that’s it.

That’s roots, rhizomes, tubers and bulbs. Now take this knowledge and spread it like a mint plant’s rhizome.

A rhizome is a root-like, underground stem, growing horizontally on or just under the surface of the ground, and capable of producing shoots and roots from its nodes. Rhizomes are most commonly produced by perennial, herbaceous species of plants, that die back to the ground at the end of the growing season, and must grow a new shoot at the beginning of the next season. Rhizomes are capable of storing energy, usually as starch, which is used to fuel the regeneration of new shoots. Rhizomes are also sometimes called rootstocks.

Plant species that have well developed rhizomes often rely on these organs as a means of propagation. However, the regeneration of plants through the spreading of rhizomes and development of new shoots is a type of non-sexual, vegetative propagation, because the progeny are genetically identical to the parent. Horticulturalists take advantage of the ease of propagation of certain plants with rhizomes by using bud-containing segments of these organs to grow new plants. This is the major method by which many ornamental species, such as iris (Iris spp.), are propagated. Some agricultural plants are also propagated in this way, such as sugarcane (Saccharum officinarum), arrowroot (Canna edulis), ginger (Zingiber officinale), and potato (Solanum tuberosa). In the case of some agricultural species, the rhizome is also the harvested part of the plant. The potato, for example, has discrete, modified sections of its rhizomes, called tubers, that are modified to store starch. Potato tubers are, of course, an important agricultural product.

Some species of tree can regenerate extensively by issuing new vegetative shoots from their underground rhizomes, after damages caused by disturbance by fire or harvesting. In North America, trembling aspen (Populus tremuloides) can regenerate very effectively in this way, and stands dominated by genetically identical “trees” of this species can sometimes occupy an area of several to many hectares (up to 40 ha). These stands may represent the world’s largest “individual” organisms, in terms of biomass.

Gardening: What Are Bulbs, Corms, Tubers, and Rhizomes?

By The National Gardening Association, Bob Beckstrom, Karan Davis Cutler, Kathleen Fisher, Phillip Giroux, Judy Glattstein, Michael MacCaskey, Bill Marken, Charlie Nardozzi, Sally Roth, Marcia Tatroe, Lance Walheim, Ann Whitman

Flower “bulbs” come in these forms: true bulbs, corm, tuber, tuberous root, and rhizome. So, what you might think of as a flower bulb may not be a bulb at all — botanically speaking, that is.

True bulbs

True bulbs, such as daffodils, tulips, hyacinths, and snowdrops, often have a papery skin or tunic on the outside, much like an onion. Bulbs with a papery covering are called tunicate bulbs. The tunic helps protect the bulb from drying out when it’s resting or waiting to be planted. However, some true bulbs, such as lilies, don’t have a tunic. These bulbs dry out faster and are more easily bruised.

All true bulbs share the following characteristics:

  • They’re more or less rounded, sort of ball-like, and narrow to a point on the top. Leaves and flower stems appear from this point.

  • With or without a tunic, true bulbs have a flat part, called a basal plate, at the bottom. That’s where roots grow and also where shoots and scales are attached.

  • True bulbs have new bulbs, called offsets, which form from the basal plate. When they get big enough, these offsets, or daughter bulbs, produce flowers on their own.

  • True bulbs are made up of rings, called scales, which are modified leaves that store food. Cut apart a true bulb, such as a hyacinth, at the right time of year, and you can find a miniature flower inside, just waiting to begin growing. Perennial true bulbs add new rings each year, from the inside. Old rings on the outside are used up, but the true bulb itself persists from year to year.

If any of the characteristics that identify true bulbs are missing, the plant isn’t a true bulb. Instead, it’s a corm, tuber, tuberous root, or rhizome. Popular corms include crocosmia, gladiolus, freesia, and crocus.

Corms have these traits:

  • Corms have a tunic. The tunic may be fibrous, what botanists call netted or reticulate, or the tunic may be smoother, with distinct rings, what botanists call annulate. Some crocuses have reticulate tunics, and others are annulate, which is one way you can tell crocus species apart.

  • Corms have a basal plate at the bottom and one or more growing points at the top. Bulbs and corms both have a definite vertical orientation.

  • Corms are undifferentiated, uniform, and contain no rings when cut apart. Corms are stem tissue, modified and developed to store food.

  • The corm you plant is used up for growing the flower. Before it withers away at the end of the growing season, however, a brand new corm (sometimes several new corms) forms and replaces the mother corm. The new corm contains the food reserve for the dormant crocus or gladiolus until it’s time to grow again.

You may not know it, but you might already be familiar with a popular tuber: the potato. Other tubers include tuberous begonia and cyclamen.

Tubers have these features:

  • Tubers have no tunic.

  • Tubers lack a basal plate. Most tubers root from the bottom.

  • Tubers have several growing points, called eyes. More organized tubers, such as caladiums or tuberous begonias, have their eyes at the top. Some tubers, such as anemones, aren’t so orderly. Distinguishing the top from the bottom of the tuber may be difficult. If you’re not sure, plant it sideways and let the tuber figure out which direction to grow.

  • Tubers are made of modified, undifferentiated stem or enlarged hypocotyl tissue. They have no highly specific internal structure.

  • Tubers don’t make offsets or produce new tubers. Tubers usually just get bigger each year, making more growing points.

Tuberous roots

Tuberous roots are modified, enlarged, specialized roots that store food, and are used up during the growing season to be replaced by new storage units. The tuberous roots cluster together, joined to the bottom of a stem. The stem contains the new growing point for the next year — a piece of root alone won’t grow.

Examples of tuberous roots are dahlias, daylilies, and sweet potatoes.

Rhizomes are stems that grow sideways rather than up, running along the surface of the soil or just below it. Plants that use rhizomes for food storage have fatter, more bulblike rhizomes, covered with a dry base of leaves. Rhizomes branch out, and each new portion develops roots and a shoot of its own.

Familiar rhizomes include iris, lily-of-the-valley, canna, and ginger (Zingiber officinale).

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