Botany

What are samaras and how are they sown?

There are many types of fruits, depending on the plant in question and the evolutionary strategy it has followed. Thus, we know that there are some that can weigh several kilos, and others that are so light that they can be held with a single finger, such as samaras.

Samaras are produced by trees and shrubs that are very special, and that are often cultivated as ornamental plants; in fact, some of those species are even worked as bonsai. But what exactly are they and how are they sown?

What are samaras?

Samaras in botany are indehiscent nuts, that is, they do not open through any valve. They are formed by a seed with a flattened wing which is made of fibrous tissue. The seed is more or less rounded, very small – the size varies depending on the species, but to give you an idea, it does not usually measure more than 0.5cm in diameter. The color also varies: as soon as they sprout, they are usually green or yellowish-green, but as they mature they turn reddish, pink, or reddish-brown, and finally brown.

This structure encourages the wind to move them away from their parents several meters or kilometers away, thus allowing the species to colonize other corners where it has not yet arrived. In this way, in addition, the new generation will be able to start life without having to compete so intensely for nutrients or space.

Types of samaras

On the one hand, we have to know that in a samara the seed can be in the center of the wing of the fruit, as for example in the case of ash trees (Fraxinus) or elms (Ulmus), or on one side of the fruit with a wing that extends from the seed to one side, as is the case with maples (Acer).

Although there is still more: sometimes instead of a samara it can be a disámara, that is to say, two samaras joined at one end as in maples; or triple chambers as in the case of the species Hiptage benghalensis.

Examples of plants that produce samara

We have mentioned a few, but it’s time to get to know them a little better:

Maples

Image – Wikimedia/ MurielBendel

The maples are trees or deciduous shrubs typically originating in the temperate regions of the northern hemisphere, especially in Eurasia. Their height ranges between 2 and 20 meters, depending on the variety and/ or cultivar, and they are characterized by having webbed leaves that turn a reddish, orange or yellowish color in spring and/ or autumn.

There are many species, but the most cultivated in Spain are: Acer palmatum, Acer pseudoplatanus, or Acer platanoides, among others. All of them require mild climates, with winter frosts, moderate watering and slightly acidic soil.

Ash trees

Ash trees are mainly deciduous trees, although there are subtropical species that are evergreen. We can find them in North America, Eurasia, and North Africa. Their height is between 15 and 20 meters, and they have a straight trunk with a crowded crown of leaves.

They are widely used as garden plants, casting a wonderful shadow. During the autumn they turn yellowish or reddish in color, which increases their ornamental value, as happens with Fraxinus ornus or Fraxinus excelsior, two of the most popular species.

Of course, it is important to bear in mind that its roots need a lot of space. They should not be planted at a distance of less than ten meters from where there are pipes, as we would run the risk of causing damage.

Elms

Elms are deciduous or semi-deciduous trees that grow in the Northern Hemisphere. They are plants with a generally straight trunk and a very wide, rounded crown that provides a most pleasant shade. They can reach a height of 25 meters, but the most common is that they do not exceed 15 meters.

Its root system, like that of ash trees, is very strong. These trees must be planted as far as possible from the pipes, at least ten meters away, otherwise there will be problems.

Unfortunately, it is also necessary to take into account that the genus is very vulnerable to a disease called graphiosis, caused by the fungus Ceratocystis ulmi. As a consequence, many species are in danger of extinction, among them the Ulmus minor that we have in Spain, or the Ulmus glabra.

How are samaras sown?

Samaras are produced by plants that live in areas where there are frosts, so if we want them to germinate we will have to sow them during the winter. But where? Well, if the temperatures drop below 0 degrees in our area, we can plant them in pots; Now, if this is not the case, we will have to stratify them in the fridge for 2-3 months.

Let’s see how it’s done:

Sowing in pots

The steps that we must follow to sow the samaras in pots are the following:

  1. The first thing to do will be to cut the wing, since if not when decomposing it could attract parasitic fungi that would damage the seed.
  2. Then, we fill a pot with soil for acidic plants if it is maple, or with mulch or universal substrate if it is elm or ash.
  3. Then, we water and place one or two seeds for each pot, laying them flat.
  4. Now, we sprinkle some powdered copper on top to prevent fungus.
  5. Finally, we finish filling the pot with substrate, and if we want to water again.

During the spring the seeds will begin to germinate.

Stratification in the fridge

If we live in an area where the temperature drops below 0 degrees but winter in general is mild, with maximum temperatures hovering between 10-20ºC then the ideal will be to stratify them in the fridge following these steps:

  1. We will fill a transparent plastic tupperware with a lid with previously moistened vermiculite.
  2. Then we will add powdered copper, as if we were adding salt to a salad.
  3. Then, we will place the seeds -without the wing-, slightly separated from each other, and lying down.
  4. Next, we will cover them with vermiculite.
  5. To finish, we close the tupperware and put it in the fridge, in the dairy section, vegetables, etc. (NOT in the freezer).

We will have them there for 2-3 months (if they are maples, we recommend that they be there for 3 months, but if they are elms or ash trees they can be eight weeks). During all that time, once a week we will take the tupperware out of the fridge and open it to renew the air, and water if we see that the vermiculite is drying.

When spring comes, we will plant them in individual pots so they can germinate and grow normally.

Image – Wikimedia/ Krzysztof Ziarnek, Kenraiz

What did you think of this topic? We hope you have learned a lot about samaras.

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