It is known as Adiantum venustum to a species of fern of the family Pteridaceae, native to China and the Himalayas, also known as “Black Hansraj” in India by the dark stems of its fronds, whose cultivation has spread to many parts of the planet especially as indoor plant.
It is a very resistant plant, largely of perennial leaf, although in regions where temperatures are registered below -10 degree C, it becomes deciduous.
Of rhizomatous roots, the specimens of Adiantum venustum can reach a maximum of 25 centimeters and they possess an elegant and clear foliage conformed by triangular fronds of green color, with numerous segments in the form of fan and with black stems. The whole plant forms a mat extending slowly, propagating by crawling rhizomes to form a colony of considerable extension.
All these characteristics give it an outstanding aspect, even among others of its kind. In addition, when new fronds emerge in late winter or early spring they are briefly painted bright bronze or salmon pink. For this reason they become a good companion of attractive species such as orchids, and are usually cultivated in beds, borders, containers and as indoor plant.
Whether it is grown in a garden or in a pot inside a house, the Adiantum venustum needs to be cultivated in a specific soil for acidophilic plants, humid, soft and with medium drainage. For the correct development of the radical apparatus of the plant, it is advisable to reimplant it every two or three years.
This species grows much better if it is located in an area with good light, but avoiding the direct sun, as this could cause unsightly burns on the fronds. We advise locating this plant in a partially shady place, where it is exposed to direct sunlight only during the coolest hours of the day. These plants have a good tolerance for cold.
Propagation, fertilization and irrigation
When grown in the garden, it can form a green carpet that can be divided in autumn to be transplanted into pieces of considerable size. The new spring growths come early and is totally imperturbable to episodes of late frost or snow.
During the warmer times of the year, fertilize the specimens of Adiantum venustum every 12 or 20 days, adding fertilizer for floral plants, especially those rich in sulfur or potassium, to promote the flowering and development of new vegetation. In this period they also need to be subjected to regular watering, always leaving the ground between one application and another. In the case of potted plants, it is recommended to use a dose of two or three glasses of water, being careful to empty the dishes of the base after each irrigation.