Distinctive features are holarena, how to grow a plant indoors, advice on breeding, dealing with difficulties, diseases and pests, curious facts, species. Holarena (Holarrhena) belongs to the botanical classification of the Apocynaceae family. The native lands of this representative of the flora fall on the territory of the Indian subcontinent, eastern Africa, China, stretching through Myanmar to Indochina. There, the plant prefers mountain forests, "climbing" to a height of 500-1000 meters above sea level. In these areas, it is found in dry evergreen and deciduous forests, as well as on rocky terrain, in the savannah or near waterways, which are located at an absolute height of about 1,500 meters.
Often, Holarena can be found in literary sources on botany under different synonymic names - for example, the Holarena fluffy variety, often called holarrhena pubescens in Latin or Holarrhena antidysenterica. And also in the English dialect Bitter oleander, connessi bark, kurchi bark or dysentery rose bay, tellicherry bark, and in India the plant is called kutaja.
Holarena in natural conditions can reach a height of up to two meters, and it is curious that in the conditions of rooms, if its branches are not cut, then it also varies within 1, 2–2 meters. It has a shrub or tree-like shape. The trunk of the plant is not too long and a small number of branches grow on it. The bark covering the trunk of the holarrhena has a gray or brownish tint. But when the branch is young, its bark is green.
Leaf plates on the shoots are arranged in opposite order, densely covering them. Leaves are attached to the branches with short petioles. The shape that the foliage takes is oval or ovoid with a pointed tip at the top. The length of the leaf varies within 10–20 cm. The color of young leaves is rich green, herbaceous; with maturation, the foliage takes on a dark green color. The veins on the leaf plate (both on the top and on the bottom) are clearly distinguishable, since they have a lighter shade.
In the process of flowering, the final umbellate inflorescences are formed. The diameter of the inflorescence is 5–15 cm. Each flower has five petals of a snow-white shade in length not exceeding 2–3 cm. Sometimes, at the very base, the petal has a yellowish speck. The outlines of the petals are oblong, with a blunt apex. As they mature, the flowers take on a creamy yellow hue. The shape of the flower, when fully expanded, resembles a miniature orchid or Frangipani flowers.
After pollination of flowers, fruits ripen in the form of pods, containing seeds that are brownish in color. The seed size is rather small. Holarrhena contains a kind of resin and because of this property, the plant is used for medicinal purposes.
The growth rate of holarena is quite high - it is up to 25-30 cm per year. The plant is considered average in terms of the complexity of care, that is, the main thing is not to violate the rules of home cultivation below.
Recommendations for home growing holarens, care
- Lighting and location selection. A place on the western and eastern windowsill is best, but the plant will be fine on the southern window, but shading is needed. If there is not enough light, then flowering will not wait. In winter, you need backlighting for at least 6 hours a day.
- Content temperature. For holarena in the spring-summer period, temperature indicators should not go beyond 24-29 degrees, and with the arrival of autumn, they are gradually reduced to 12-16 units.
- Air humidity when grown, it is kept not lower than 60%. It is necessary to regularly spray the deciduous mass with soft and warm moisture, but it is better not to get on the flowers, as they will turn brown.
- Watering. For this plant, a resident of the tropics, it is recommended that in summer, abundant soil moisture, when the topsoil began to dry out. In the autumn-winter period, it is recommended to keep the substrate in a semi-dry state. Both the complete drying of the earthen coma and its bay are strictly prohibited. When the water is drained into a pot holder, then it must be removed after 10-15 minutes, otherwise it can later lead to the beginning of decay of the roots. Water should be used only warm and soft.
- General information on care. In summer, it is recommended to take the plant pot out into the open air - on a balcony, terrace or garden. In this case, shading and protection from rain and wind will be required. When growing in rooms, frequent ventilation is needed, but the holarena is placed away from the draft. Due to the high growth rate of branches, constant shaping of the crown of a bush or tree is needed. After the dormant period ends (with the onset of spring), shoots that are too elongated, weak or deformed, as well as those that grow inside the crown, should be cut off. This will ensure good flowering in the future.
- Transplant tips are holareny. When the plants are young, it is recommended to change their pot every year, but in the future (after three years) such operations are performed no more often than once every 2-3 years. In this case, the new container must be voluminous. Transplants should be carried out in the spring, when 2-3 days have passed after watering. When the plant is taken out of the old pot, the root system can be cut off a little (only 5–7 cm) so that the holarrhena does not grow much. This method is often used in bonsai cultivation. When a bush or tree becomes very large, then replanting it is already difficult and just a change of 3-5 cm of the topsoil is performed. In the bottom of the new container, it is necessary to make small holes through which moisture that has not been absorbed by the roots will flow out. A good drainage layer is also required. It can be both expanded clay and pebbles, but in the absence of such, medium-sized pieces of broken brick or ceramic (clay) shards are used.
The soil for holarena needs nutritious and well-drained soil. If the grower makes the substrate himself, then it is recommended to use the following components:
- leafy soil, sod soil, peat, coarse sand or perlite (in proportions 2: 1: 1: 1/2);
- sod, peat substrate, humus soil, river sand (2: 1: 1: 1, respectively).
Breeding tips at home
To get a new plant with snow-white flowers, it is recommended to root cuttings or sow seeds.
In the case of cuttings, it should be remembered that this operation is not an easy one for holarena. It is required to cut blanks from the tops of the shoots so that their length is not less than 8–12 cm, and leave only a couple of leaves on them, since moisture will evaporate more actively from a larger number of leaf plates. Before planting, the cut of the cuttings should be treated with a root stimulator (Kornevin or heteroauxinic acid), then it is dipped in a fungicide.
Planting of cuttings is carried out in pots filled with a substrate of peat and sand, often one perlite is used or perlite mixed with leafy soil. To make the workpiece more stable, the first layer of the substrate is laid, then the perlite, the cutting is placed in such a way that its cut is completely immersed in perlite, and sprinkled with the same soil on top. The germination temperature is maintained at 21-28 degrees. The place where the container with the blanks is placed should be in shade from direct sunlight, but be sufficiently light.
Often, for early rooting, the conditions of a mini-greenhouse are applied, when the cuttings are placed under a cut plastic bottle or covered with a transparent plastic bag. Then the care will consist in daily airing for 10-15 minutes, and if the soil in the pot dries up, then it should be moistened. Rooting of holarena cuttings can take up to a month. When it happens, young plants are transplanted in separate pots with a more suitable substrate.
If seed propagation is used, then the material should be placed in pots with a diameter of 6 cm. Before planting, it is recommended to soak the seeds or wrap them in moistened gauze for a day. The substrate in pots is used peat-sand or peat-perlite. A piece of glass is placed on top of the container or covered with plastic wrap. Ventilation and, if necessary, watering of the soil will also be required. After a couple of weeks, you can see the first shoots of holarena. Seedlings grow very slowly, so it is worth replanting them only if a couple of real leaves unfold on the plant. It has been noticed that after a year, holarrhena seeds lose their germination.
Fighting hardships, diseases and pests when growing holarena
If the owner does not monitor the conditions of keeping the plant, then due to the decrease in humidity in the room, it can be affected by harmful insects, such as spider mites, scale insects or mealybugs. In order to get rid of pests, you will need to wash the deciduous mass under a warm shower. Then wipe the sheet plates on both sides with soap, oil or alcohol. After holarena is sprayed with an insecticide, Aktara, Aktellik or Fitoverm can act as it.
If the plant is in a strong shade, then its leaves will grow small, the shoots will be strongly elongated. When the soil in the pot is constantly in a waterlogged state or too dry, the foliage becomes yellow and flies over time. With constant exposure to direct sunlight on the leaves, sunburn is possible, which are manifested by drying out of the tops and brown spots on the surface.
Interesting facts about Holarene, plant photos
It should be remembered when caring for holarena that the plant is toxic, therefore, when pruning, it is necessary to avoid getting juice on the mucous membrane and skin.
If we talk about some varieties (for example, Holarena pubescens Wall. Ex G. Don), they have long been known for their medicinal properties. According to Ayurveda, this representative of the flora is the main remedy for dysentery and diarrhea. Also, doctors of Indian lands attribute properties in as an antiseptic, antipyretic, helping to reduce inflammation.
But it should be borne in mind that this plant is not recognized by the official medicine of Russia and is not used as a medicinal product. In some European countries (including on the territory of Ukraine) there is a permit for the use of dietary supplements based on fluffy holarena extract. At the same time, there is information that the herbal remedies of this representative of the flora can have astringent, antipyretic, as well as diuretic, antiseptic and other beneficial effects.
But it should be borne in mind that contraindications and some side effects from the use of funds made from fluffy holarena have not been fully investigated by science and therefore such drugs are not recommended for people with individual intolerance. It happens that an overdose can cause mild indigestion, mild hand tremors, or fatigue. If such symptoms are present, then it is recommended to stop taking the drug, and in the future it will be necessary to reduce the dosage and consult a doctor.
Since there is no information about the effect of such drugs on pregnant and lactating women, the elderly or young children, you should not experiment with them without medical advice. There is an ancient Indian legend (in the Ramayana epic), according to which kataja (as the fluffy holarena is called in India) was formed from drops of amrita, the famous nectar that gives immortality. This liquid fell to the surface of the planet from the bodies of monkeys that fell in the battle between the god Rama and the revived deity Indra. The monkeys were on the side of the first god and remained in the legends. Also, the seeds of the plant are called "Indra seeds" or "Indrayava".
- Holarena fluffy (Holarrhena pubescens)is probably the most popular species in the family. It is a medium-sized deciduous plant (tree or shrub), reaching 3, and sometimes even 10 meters in height. The trunk is short, with a diameter of about 20 cm, covered with pale brown or grayish bark. Its surface is covered with multiple cracks. On the trunk, several branches usually grow at first with a whitish tint. The fracture of the shoots is fragile, splintery. The bark and wood have no smell, but they have a bitter taste. The foliage growing on the branches is in opposite order. Its outlines are oval, elliptical or egg-shaped, there is a rounding at the base, and a sharpening is present at the top, or it may be blunt. The surface of the leaf is membranous, with pubescence. The length of the leaf plate is 10-24 cm with a width of 4-11.5 cm, but there are specimens with leaves equal in length to 20-43 cm and a width of only 1.5 cm. The petioles of the leaves are short - only 0.5 cm. Flowering begins opening of elongated buds, in which the petals seem to be coiled in a spiral. The flower has five petals in the corolla. Their color is snow-white, but then it changes to creamy yellowish. The corolla may have pubescence, its shape is tubular, the length of which is 1.9 cm. The lobes in the corolla are oblong. The flowers are shaped like orchids. From the buds, inflorescences are collected, located at the tops of the branches. The shape of the inflorescences is corymbose, with a length of up to 5–8 cm, their pedicels are 1–2 cm. The outlines of sepals are elliptical or linear, measuring 1, 2 cm in length. The flowering process occurs in April-July. When the fruit ripens, a pod is formed, filled with small seeds with a light brown tint. It is this variety that is used in medicine and it is called Bitter Oleander or Holarrhena pubescens / Chonemorpha / Echites antidysenterica. In Cambodia, the plant is named "invulnerable snake" or "big tiger milk".
- Holarrhena floribunda It can be both a shrub and a small tree, while the height of the trunk of the latter can reach 25 m with a trunk diameter of up to 30 cm. Flowers with a strong aroma are cast in a snow-white color scheme. The fruit is a pod from a pale gray to dark brown tone, filled with seeds, it reaches about 60 cm. This plant is popularly known as "false rubber tree" and "Curchi bark". The plant is found on an area up to 1000 meters above sea level in Senegal, Gambia, Guinea-Bissau, Guinea, Mali, Burkina Faso, Sierra Leone, Liberia, Cote d'Ivoire, Ghana, Togo, Benin, Nigeria, Chad, Cameroon, Central African Republic, Gabon, Republic of the Congo, Democratic Republic of the Congo. It is curious that the peoples used this variety as a poison for arrows, and also its properties were used in medicine.
- Holarrhena mitis a small tree decorated with fragrant flowers. The plant can be found in the lands of Sri Lanka, at an absolute height of about 450 meters. The bark of the trunk is smooth, whitish and soft, its surface is fine-grained. The wood has a yellow-white color. Common names include kiri-mawara or kiri-stena in Sinhal and kuluppalai in Tamil.