The genus Cyrtomium has 43 species of ferns and belongs to the family Dryopteridaceae. These plants are found in Asia, Africa (including Madagascar) and the Pacific Islands (Hawaii), the center of species diversity is located in Southwest China.
The name of the genus comes from the Greek kyrtos (arched), indicating the curved leaves of the fern, forming a vase-like habit of the plant.
Representatives of the genus are terrestrial evergreen perennial plants. Rhizome erect or ascending, short, densely covered with monochromatic or two-colored scales, from dark brown to blackish brown. Leaves, 2-6 on each rhizome, scaly at the base, from linear-lanceolate to broadly lanceolate or deltoid-ovate, imparipinnate, the upper leaflet is somewhat dissected, rarely simple; leaf axis from above is furrowed, scaly. Leaflets are lanceolate, ovate-lanceolate, crescent or ovate, whole or dentate along the edge; leathery or papery, rarely finely papery, with reticular veins. Sori are rounded, arranged in one or several rows on each side of the midvein.
Sickle cyrtomium (Cyrtomium falcatum) is widespread in nature in China, Indochina, Japan, Korea, the islands of the Pacific Ocean (Polynesia); introduced and naturalized in Europe, Hawaii, North America, Reunion, South Africa. Grows in coastal and lowland forests up to 500 m above sea level.
Evergreen fern 30-40 cm tall. Rhizome erect, densely covered with lanceolate brown scales. The frond’s axis is hollow, 15-27 cm long and 3-4 mm in diameter, densely covered at the base with ovoid, at the bottom with fringed scales of light brown, sometimes blackish-brown color. Leaves broadly lanceolate, 22-35 cm long and 12-15 cm wide, narrowed at the base, pinnate, pointed, bright green, leathery, shiny, glabrous on both sides; rachis with lanceolate brown toothed scales or glabrous.
Leaflets, 5-14 pairs in number, alternate, spreading or ascending, on short petioles, lanceolate or ovate-lanceolate, often crescent-curved; median leaflets 6-10 cm long and 2.5-3 cm wide, obliquely rounded-wedge-shaped at the base, whole or membranous along the edge, sometimes wavy or dentate, long-pointed or drawn at apex; terminal leaflet ovate-lanceolate, bifurcated or tripartite, 4.5-8 cm long and 2-4 cm wide. Sori are located along the entire lower surface of the leaves.
The soil required is moderately fertile, rich in humus, moist, but well-drained. It is best to compose it yourself from the following components: sod land: leafy earth: sand (1: 3: 1), bring the acidity to slightly acidic or neutral. Of the purchased land mixtures, the soil is optimal for ground orchids, but you can also use a high-quality universal one.
Due to the slow growth of the plant, transplantation is rarely performed, every 3-5 years, as the earthen coma is developed. The pot for him is selected wide and not very deep.
Lighting. This fern naturally grows in the shade of forests. In indoor conditions, it needs bright diffused lighting, it grows well in shaded places, but it should still receive enough daylight. It can be placed on east, west and even north windows. On the southern ones, shading is required (best of all, blinds) or placing a plant 1.5 m from the window.
Temperature. For Cyrtomium, the average room temperature throughout the year is suitable, within the range of + 21 … + 25 ° C. In autumn, the temperature can be reduced to + 12 … + 20 ° C, but this is not necessary. The plant can withstand a minimum temperature of + 10 ° C and a maximum of + 27 ° C, but it is better not to approach these limits, keeping the plant cool.
Watering. Cyrtomium must be constantly kept moist, but not over moistened – this requires good drainage throughout the entire volume and light drying of the upper layer of the substrate between waterings. The soil must not completely dry out. Under unfavorable conditions (dry air, improper watering), the tips of the leaves may dry out. When kept cold in the autumn-winter period, they are watered less often, preventing the coma from drying out.
Humidity is needed moderate, in the range of 40-50%. In a warm place at temperatures above + 21 ° C, measures should be taken to increase the humidity – put the pot on a pallet with wet expanded clay and spray it daily with cold, settled water.
Topdressing is applied every 2 weeks during the active growing season. They use a complex mineral fertilizer for ferns in a half concentration, which is alternated with the introduction of organic matter (liquid Biohumus, Lignohumate, Potassium humate). From autumn, feeding is stopped until March.
The rest period in Cyrtomium sickle is not pronounced. It is able to winter both at low room temperatures and at low temperatures (+ 12 … + 20 ° C) from October to February. In this case, the temperature should not fall below + 10 ° C. During the period of cold keeping, the plant is watered moderately and not so often, feeding is canceled until spring.
Pests. The plant is affected by the scale insect. It is not recommended to use chemical sprays for pest control, as the leaves can get burned. The scabbard can be removed with a blunt knife and the plant is poured under the root with Aktara.
Types and varieties of Cyrtomium
In botanical books, 12 species of Cyrtomium are included in the registration. However, only one of them can be grown at home – this is the crescent Cyrtomium.
Is a widely spreading shrub up to 60 cm high. In the natural environment, it can be seen in Africa and Japan. Differs in high resistance to low temperatures and low air humidity. It has long, rich green fronds with a gray coating, which are formed from unpaired, pinnately dissected leaves. The length of frond is about 40-50 cm, width is 10 cm, the edges of the leaves have uneven dissections and rare teeth. In garden stores, you can most often find the Rochfordianum variety, which is characterized by glossy leaves of a dense texture.
These bushes can be seen in China, Japan or Korea. Their leaves are up to 60 cm high and consist of elliptical or triangular segments of a light green or grayish color. And of a lying configuration, they have long brown petioles. The leaves are attached at some distance from each other.
This specimen is distinguished by a light brown root system covered with small scales. The shrub consists of dense, upright fronds up to 70 cm high. The leaves are formed from large segments with uneven edges. The color of the leaves is gray-green. The appearance of the leaf resembles large bird feathers. The decorativeness of the bush attracts gardeners, but it is very difficult to see such a plant in stores.
This shrub is formed from large frond, which are held on rigid petioles and are about 70 cm long and about 30 cm wide. The front side of the leaf plate has a glossy surface and pronounced dark green veins. The segments have an elongated lanceolate configuration and grow in pairs. The ends of the leaves are pointed. On the back of the leaves, dark green sporangia are kept, which, after ripening, spill out into the ground and germinate.
This type of fern is a densely spreading shrub, consisting of a large number of frond. The leaves consist of 15 pairs of elongated-ovoid light green segments, each of which has a length of 10 to 15 cm and a width of about 5 cm. This type of fern is the rarest and rarely found in cultivation.