For the identification of insects and other fauna and flora of South Africa.

Monday, July 15, 2013

Emerald Fern (Asparagus densiflorus)

Family Asparagaceae
Description
Asparagus densiflorus is a scrambling, slightly woody plant with upright or trailing branches up to 1 m long. The appearance of the plants varies enormously and has led to the naming of a large number of cultivars or forms. The best known forms belong to the so-called emerald ferns of the Asparagus densiflorus 'Sprengeri' group. These plants form large cushions with long, arching stems more or less densely covered with dark green, needle-like leaves. The plants of this group can be used as groundcovers in shade as well as in full sun, or in large containers or hanging baskets. The cultivars 'Cwebe' and 'Meyersii' form more upright plants, particularly 'Meyersii', which looks very different, with its compact cat's tail-like fronds.

Asparagus densiflorus flowers are small, most often white or pale pink and are very sweetly scented. The flowers are not very noticeable, as they are half hidden by the foliage and do not last long. They flower for about two weeks during the summer season, in South Africa as well as in the Northern Hemisphere. The flowering of the plants can be rather erratic, with the plants having a good flowering year on average only once every three years. The small flowers are followed by showy bright red berries, which each have one large black seed in them. The berries are attractive to birds and may be spread by them.

It is an extremely versatile perennial, evergreen plant that can be used as a groundcover or container plant in full sun or light shade. Although there are many striking and beautiful South African Asparagus species, most of them have horrendously large or sharp spines. A. densiflorus has only very small, hardly noticeable spines and is an excellent garden plant.

Distribution

Asparagus densiflorus grows in the coastal areas in the southeastern Cape and KwaZulu-Natal in a wide range of habitats, from coastal dunes to open rocky places or woods.

Name and history

The earliest record of a South African asparagus is an illustration from 1686, while plants from the 'Sprengeri' group were introduced into cultivation as early as 1888. They are now grown all over the world and have proved hardy, drought tolerant and even fairly salt tolerant plants which can be used as garden plants or for cut foliage.

Uses

One other South African species that is widely cultivated is Asparagus plumosus, which has flat, feathery short stems and used to be found in almost every bunch of cut flowers as foliage. Some of the South African Asparagus species are used as vegetables or for medicinal purposes. The berries cause only low toxicity if eaten. When the berries are crushed, skin irritation is minor, or lasting only for a few minutes.