Today we are going to talk about the genus Liquidambar and more specifically about the best-known species of the genus which is the Liquidambar styraciflua or commonly called American liquidambar . This large tree will not be suitable for small gardens, but having space is a real spectacle especially in my favorite season of the year, autumn. Let’s get to know more about this fabulous tree for the garden.
THE GENUS LIQUIDAMBAR AND ITS FABULOUS NAME
In Gardenprue we always say that etymology often gives us clues to the name of some species. Do you remember or know the Mirto ? The word Mirto comes from myrtus, perfume in Latin, since it is a tree that has mirtol, a pleasant perfume that this species gives us.
In the case of liquidambar, instead of associating its name with the smell, we are going to associate it with the color, the amber of its resin that slides down its trunk and that has been used traditionally as we will see later. Liquid amber, with that we have just described a genus belonging to the Altingiaceae family of only 5 species, among which is the one we are going to talk about today. The 5 recognized species are:
- Liquidambar styraciflua L.
- L. acalycina H.T.Chang
- L. cerasifolia (Wall. & Griff.) Voight
- L. formosana Hance
- L. orientalis Mill.
There are other names but they are not yet taxonomically resolved or they are synonymous with these 5. As we can see, the genus was described by Carlos Linnaeus and L. styraciflua was the first. The others are other later descriptors. All liquidambar are large deciduous trees . They can reach up to 40 meters without disheveled so it is not a tree for small gardens precisely. Anyway, his normal height stays between 20-30m which is not bad either. Its 5-pointed leaves “similar” to those of the maple turn to very capricious colors in autumn , from yellow to a purple aubergine through the entire color range of warm giving a spectacular reddish tone. Hence its scenic appeal.
L. styraciflua L. is of American origin and is very present in Central America and central eastern North America. In Europe it is somewhat less present but it does occur in central Europe. In Spain in particular there are certain points in the Cantabrian area, Galicia and part of the southern mountains of the country. Sure there will be more places where you are but this gives us a general idea of the current world distribution.
LIQUIDAMBAR STYRACIFLUA L. THE MOST PRECIOUS FOR GARDENING
Before talking about the cultivation we must bear in mind that the establishment of the tree costs at the beginning. Until it is rooted and comfortable, its roots may suffer , and even in good conditions its growth is somewhat slow during the first 3 years. From there its growth speed increases a lot. We could say that it “hits the stretch” and reaches maturity where its growth rate drops again. With this we warn that it is a very delicate tree and that it is not very suitable for long-term small gardens. Keep in mind that you must leave a radius of at least 3 meters from any structure, house or similar since the roots can create a significant damage.
Warnings aside, it has several attractions for the garden.
- In the first place, its trunk, with deep grooves of bark through which the resin flows.
- The color of its leaves, from the intense spring green to the whole range of warm throughout the fall.
- Its conical cup structure
- Its wood is highly prized and has been used for furniture, although this will not be an important feature for the garden but it had to be mentioned.
LIQUIDAMBAR CARE IN THE GARDEN
TEMPERATURES AND SUN EXPOSURE
It is a tree with temperate climates, although in winter lethargy it can withstand intense cold down to -20º C, so we should not be afraid of winter. You can have a hard time in the early years. Once this is over, no problem. It needs direct exposure to grow vigorous although it can also grow in semi-shady areas. If the summers are too intense of heat and the exposure is direct, it will be necessary to be more aware of the irrigation.
In this section is where more special care must be taken and the one that will largely limit the choice of this species or another. It needs acid soils , typically forest. Limestone soils, typically alkaline, do not do well and must also be nourished in organic matter. In short, fertile, drained and slightly acidic soil . We will abstain from clay or silty soils, which is often called heavy soils. It also does not support saline soils so we forgot to cultivate them on the coast.
The problems beyond diseases and pests (which it has few) are largely due to inadequate soil. Soils described above as unsuitable can suffer from severe iron chlorosis .
If you are going to have a liquidambar in the garden, you should monitor its watering especially in the summer months , taking into account that you are going to plant it in a climatic zone of frequent rains for at least the rest of the year. As you can see on the map that we have shown you previously, you will see that most of them occur in the north of the peninsula where the rains are abundant. If you dare to plant it in drier but colder areas (typical Castilian plateau) you should be attentive to watering since it requires a moist but not flooded soil .
Interestingly, the liquidambar has a pyramidal structure in its glass and it really does not need to be pruned too much. You have a natural tendency to be organized and balanced. Yes it is convenient to remove dead branches but little else. If you want to prune, it should be done in autumn and the pruning should be gentle, not as in other species such as photinias where aggressive pruning favors the density of later shoots.
ITS RESIN AS A USABLE RESOURCE
As with rubber, something similar happens in the case of liquidambar and that is that there are crops of this tree to collect its resin that is used by the chemical industry. In chemical jargon this resin is called styrax . This resin is very aromatic and is used to extract aromas in the cosmetic and perfume industry . It has been used in ointment to treat scabies and other parasitic skin diseases. It is also used in inhalations of colds of the upper respiratory tract, in perfumes, topical protector, expectorant, some perfumery uses, aerosol fragrances and in veterinary medicine, it is used as a parasiticide.
The extraction process may seem somewhat “cruel” because it consists of making a wound to the tree. Resin is its natural healing agent and it is what we get from its “cultivation”. From these wounds we obtain the resin during a series of harvests, without letting the tree faint.
In reality, the balance is sought, so that over time, that wound heals and another incision can be made in another part of the cortex to continue obtaining product. The styrax or also called storach is obtained from many other species, not only from the liquidambar, which also produce this type of healing compound for the wounds of its bark. They are often confused with other species of the genus Styrax from which a resinous liquid is also obtained.
THE PIGMENTS IN ITS LEAVES ARE ALSO USED TO DYE FABRICS
We have to be honest. I did not know this lustrous tree in the forest, neither reading in books nor in a nursery. I know him thanks to a craft of printing on fabrics using various techniques that use hot water and steam, tannins, iron oxides and other compounds to remove and fix the pigments in a fabric. Curiously, the liquidambar leaves are one of the species that are best in these prints on fabric and the results are incredible. Through these techniques I got to know the leaf and therefore the tree. As a curiosity, apart from the liquidambar, the red cochineal obtained from the insect ( Dactylopius coccus ) that colonizes prickly pears, for example, is also used. This deep red pigment is a compound called carminic acid (hence carmine red).