SUMMARY
Penrock Seeds and Plants is busy with a programme for introducing some of South Africa's unusual and ornamental plants to horticulture. For the past few years the nursery has been propagating specially selected clones of Zantedeschia jucunda and Zantedeschia pentlandii for use in ornamental container planting. As part of the same programme an unusual new genus related to Tulbaghia has also been propagated. This plant is proving to be ideal for planting in large bowl-shaped containers with ornamental rocks.

The newsletter provides an account of how these plants can be used for ornamental container planting.

The creamy yellow flowered Zantedeschia jucunda in full flower on the summit of the Leolo Mountains in Sekhukhuneland. The photograph was taken at the peak of an exceptional flowering season in late November 2003.

NEWSLETTER.
ZANTEDESCHIA JUCUNDA.
Zantedeschia jucunda is endemic to the summit of the Leolo Mountains in Sekhukhuneland. It is one of South Africa's most beautiful bulbous plants but propagated plant material produced through cultivation programmes, has only recently started to become available.

Some five years ago selected clones of this species were pollinated in the nursery at flowering time. The plants selected for pollination were characterised by copiously white spotted leaves and large richly coloured cream or chrome yellow flowers.

A parallel programme was started with a local person living on the summit of the Leolo Mountains. Training in propagation techniques has been provided and the first crop of plants is currently under production in the mountain top nursery. This venture has been jointly undertaken by Random Harvest Nursery situated in Honeydew Johannesburg, and Penrock Plants also in Johannesburg .

A third arm of the project concerns the tissue culture of some of the most beautiful Z. jucunda clones. These will be offered in due course as cultivars via a large international bulb company based in Johannesburg.

The chrome yellow flowered Zantedeschia jucunda is mostly restricted to the southern end of the Leolo Mountains.

ORNAMENTAL CONTAINER PLANTING WITH ZANTEDESCHIA JUCUNDA.
Z. jucunda thrives in large terracotta containers. Groups of tubers should be planted some 5 - 6 centimetres below the surface of the soil.

The ornamental white spotted foliage is handsomely displayed when the tubers are planted amongst rocks or boulders artistically placed in the containers. Variably coloured rocks offset the leaves at their best particularly those of a reddish brown, ochre or chestnut brown colour. These conditions mimic the situations where the plants grow on the summit of the Leolo Mountains.

Zantedeschia jucunda often occurs in rock crevices on the vast rock domes which are frequent on the summit of the Leolo Mountains.

In South Africa Z. jucunda provides beauty and interest from October to March. The leaves look at their best in the period October to early November before the flowers appear, later in November and December. The plants are likely to grow just as well in many other regions of the world.

Landscapers interested in ornamental container planting can make good use of this plant. It thrives in sunny positions. The tubers should be regularly watered in summer and once established do not require specialised care. They need to be kept dry during the winter months.

Zantedeschia jucunda is now widespread in rock walls made by the pastoralists living on the Leolo Mountains. This artificial habitat has greatly benefited these beautiful arums.

ZANTEDESCHIA PENTLANDII.
Z. pentlandii is endemic to the rocky hills and mountains near Roossenekal and Tonteldoos in Mpumalanga. This species with its characteristic golden yellow flowers has been known in cultivation for some time.

Penrock Plants has, in recent years, selected specific clones for their large dark green leaves and big deep yellow flowers. These plants have been propagated from seed in the nursery.

Some groups of Zantedeschia jucunda produce flowers with a rich burgundy wash. These plants are rather rare mainly found growing on the central parts of the Leolo Mountains. The important point with respect to Z. pentlandii is to introduce variety into the existing range of clones which have been available for many decades.

Zantedeschia jucunda is particularly suited to ornamental container planting. These plants form a group amongst lichen blotched rocks in a terracotta container. The photograph was taken in the early summer when the leaves are at their best.

PLANTING ZANTEDESCHIA PENTLANDII IN CONTAINERS.
Z. pentlandii is ideally suited to container planting and grows very well in large deep terracotta containers. These deep containers are much like the natural rock fissures filled with soil where the plants grow near Roossenekal and Tonteldoos.

The plants are best displayed amongst tall angular brown rocks in tightly packed groups. The tubers should be planted some 4 - 5 cms below the surface of the soil and the plants should be watered regularly during the summer months.

A combined planting of Z. jucunda and Z. pentlandii is very striking and makes for an accent feature on a sunny patio.

Zantedeschia pentlandii has dark green leaves and golden yellow flowers. This photograph was taken near Tonteldoos in Mpumalanga. The plants typically grow in rock fissures.

THE NEW GENUS FROM THE SUMMIT OF THE LEOLO MOUNTAINS.
The new genus related to Tulbaghia from the summit of the Leolo Mountains is a narrow endemic and is considered to be critically endangered in habitat. It has however, proved to be possible to propagate these plants in large numbers and the bulbs reach flowering size in only 2 - 3 seasons when grown from seed.

This dwarf species flowers throughout the summer months producing masses of small white cup shaped flowers. It is ideal for use as a water feature or else for planting in wide ornamental containers.

The bulbs should be grown in small groups amongst ornamental stones. They look particularly attractive when planted amongst brown or buff flattish pieces of rock. Small gaps should be left between the rocks about 2 - 5 cms wide. These gaps quickly fill up with young bulbs produced from seeds which fall from the parent plants. After a few years hundreds of bulbs compete with one another for space and form dense groups covered in white flowers. They flower for long periods in the summer.

Zantedeschia pentlandii often grows together with Aloe castanea in the mountains near Tonteldoos.

The plants should be grown in a heavy clayey soil and kept well watered in the summer months. They should be allowed to dry off during the winter. If the plants form part of a water feature, the area where they grow should be allowed to dry out completely in winter. If the water feature is not designed so areas can dry out in winter the bulbs should be planted in containers which can be removed and kept dry for the duration of the winter.

The bulbs are equally at home when planted in a wide ornamental terracotta bowl well away from water features. These bowls may be displayed on sunny patios where the mass of white flowers provides a striking display for many of the summer months.

A new genus related to Tulbaghia occurs in seepage areas on the summit of the southern section of the Leolo Mountains. This rare narrow endemic is proving to be an interesting feature plant for container planting. It is readily propagated.

FURTHER READING.
These plants are discussed in detail in various references which are listed below.

The new genus related to Tulbaghia creates impressive displays of thousands of white flowers massed together, in seepage areas on the extensive rock domes of the Leolo Mountains.

Stefan Siebert and Braam van Wyk. Sekhukhuneland, Floristic Wealth versus Platinum and Chromium Riches. Veld and Flora Volume 87 (4) December 2001: 168-173.
Charles Craib. Zantedeschia jucunda and Zantedeschia pentlandii. The beautiful yellow arums from the Sekhukhuneland Centre of Floristic Endemism. Veld and Flora. Volume 89 (3) September 2003: 106-109.
Charles Craib. Stone Walls and Stock Farmers. Veld and Flora Volume 90 (2) June 2004: 52-53.
Charles Craib. The Autecology of Zantedeschia jucunda and Zantedeschia pentlandii from South Africa's Limpopo and Mpumalanga Provinces. Herbertia Volume 57: 77-86.
Charles Craib and Stefan Siebert. A New Genus related to Tulbaghia from seepage areas on the summit of the Leolo Mountains, South Africa. Herbertia Volume 57: 87-92.

Contact person for the Zantedeschia jucunda project on the Leolo Mountains:
Linda de Luca. Random Harvest Nursery. Email linda@rhn.co.za