Othonna herrei during its summer dormancy. These plants make very ornamental container subjects. These othonnas have been planted in a hand made terracotta pot with a rough finish.

The plants are grown from seed produced in the nursery. They are available for sale when they are 2 - 5 years. Also propagated in the nursery are several unusual Othonna hybrids, and new species.

Othonna cakilifolia is a caudiciform species with attractive mauve flowers borne during the winter growing season.

The different species and hybrids produced in the nursery are discussed in this newsletter. There are also photographs of most of the Othonnas propagated by Penrock Plants for people who wish to view them.

The hybrid Othonna herrei x Othonna nova species Rosyntjieberg has ornamental trunks resembling tortoise shells.

NEWSLETTER.
Caudiciform and succulent Othonna species have particularly attractive foliage, flowers and trunks. Some of the most ornamental succulents in South Africa and south western Namibia are to be found amongst the different species in the Genus Othonna.

The species are all winter growing. They either flower whilst in active growth or else in the autumn months before the development of leaves.

The various caudiciform and succulent species offered by the nursery are discussed below.

Othonna furcata at the beginning of its winter growing season.

CAUDICIFORM OTHONNAS STOCKED IN THE NURSERY.
The Genus Othonna is in need of revision since several new species which have been found in the past two decades require formal description. One of these is to be found in northern Namaqualand where it is narrowly endemic to the hills around Steinkopf. These plants have large ornamental corky textured tubers which are borne partly exposed above the ground. They produce a compact ornamental rosette of palmate grey leaves in the winter months and lemon yellow flowers in the autumn and early winter before the leaves appear or at the beginning of the leafing season.

Another more widespread apparently undescribed caudiciform Othonna is found along the Swartruggens escarpment which lies at the extreme south western section of the Ceres Karoo. These plants have rounded fissured tubers and large simple leaves marbled with buff reddish brown and underlying purple blotches. A profusion of yellow flowers is borne during the mid-winter months of June and July.

Othonna cackilifolia is another rare caudiciform species produced in the nursery in limited numbers at present. The plants have rounded simple leaves and bright mauve flowers.

Two widespread species with attractive flowers and foliage are produced in the nursery namely Othonna intermedia and Othonna sonchifolia. O. sonchifolia has long distinctly serrated leaves borne in a lax rosette. It is quite commonly found in the Western Cape extending into southern Namaqualand. O. intermedia has large simple rounded leaves and conspicuous bright yellow flowers. It occurs in dry sandy rocky areas in various parts of eastern Namaqualand and also the northern part of the western Karoo, near Calvinia.

SUCCULENT OTHONNAS GROWN IN THE NURSERY.
The nursery specialises in producing a wide range of succulent Othonnas. These are discussed below. Othonna retrofracta as it is presently known, is a very variable species. Plants around Worcester and south west of Robertson in the Western Cape have large rounded ball-shaped caudexes borne above the ground. These give rise to the main stem or else a mass of twigs and leaves. This is one of the most ornamental forms of this species and ideally suited to pot culture. O. retrofracta found growing on the Swartruggens range bordering the Western Karoo, has very distinctive thick golden trunks with peeling bark. These plants resemble almost exactly bonsai trees, particularly when they are wedged into rocky crevices. The O. retrofracta around Clanwilliam have trunks shaped like soda water bottles and tan or creamy yellow trunks. They make very ornamental container subjects for a succulent collection.

Othonna euphorbioides is widely distributed on the granite domes of central and northern Namaqualand and is a particularly handsome species. It has very thick trunks and masses of simple grey leaves borne amongst compact arrangements of spines. These plants have been popular in cultivation for a long time. They are grown very hard in the nursery as close to the natural conditions as possible. This ensures that they keep their compact habit.

Othonna wrinkleana is a newly described species from the Nuwerus area of Southern Namaqualand. The plants have so far only been found on the summit of one mountain. This is a dwarf species with several squat branches in older plants. The rounded above ground caudexes of young O. wrinkleana are very similar to those of Othonna cacalioides. This is one of the few Othonna species that reaches flowering size towards the end of its first growing season.

Othonna lepidocaulis photographed at the beginning of the leafing season in early winter. This ornamental species is ideally suited to container planting.

One of the most ornamental of all the Othonnas is Othonna lepidocaulis. This species has a rich golden yellow branched trunk and occurs at a few places in central Namaqualand. Plants from the Riethuis area in west central Namaqua-land have thick succulent spear-shaped leaves whilst those found south of Bitterfontein have distinctively undulate "crinkled" margins to their succulent leaves.

One of the most popular, robust and attractive of all the succulent stemmed Othonnas is an undescribed species from the summit of the Rosyntjieberg in the northern Richtersveld. This plant, originally incorrectly identified and distributed as Othonna cyclophylla, has large thick branched stems with a dense white velvety pubescence at the growing points on the branches. This species is spectacular and makes an interesting addition to any succulent collection.

Othonna herrei has long been a favourite. This species with its knotted stems is endemic to hills and mountains of the southern Richtersveld where it is rather rare. The species is fortunately readily propagated.

Othonna armiana is a rare species so far only recorded from one mountaintop north east of Eksteenfontein in the Richtersveld. The plants have very ornamental stems with masses of closely packed tubercles. This species is extremely slow growing and rarely starts to branch until it is 5 - 6 years old.

Othonna retrorsa is a mound forming species. Some very robust specimens occur on Khamiesberg in Namaqualand where they frequent depressions filled with sand on vast granite domes. Smaller compact plants occur around the Spektakel Pass west of Springbok in Namaqualand.

OTHONNA HYBRIDS PRODUCED IN THE NURSERY.
Some very attractive Othonna hybrids have been produced in the nursery. These are always in rather limited numbers since hybrids are usually shy to set seeds and many flowers are infertile. The most attractive hybrids are Othonna herrei x Othonna armiana and Othonna herrei x Othonna nova species, Rosyntjieberg. These are two robust hybrids and a small number of others are grown from seed in the nursery each season. An extraordinary hybrid is Othonna retrorsa x Othonna lepidocaulis which is extremely slow growing. Some Othonna hybrids which have great potential for container plants produce no fertile seeds from one season to the next. One such hybrid is Othonna wrinkleana x Othonna nova species, Rosyntjieberg.

TIMES OF THE YEAR AT WHICH OTHONNAS ARE AVAILABLE.
Othonnas are available from April to October. In the case of the caudiciforms they establish best when sent to the northern Hemisphere at the beginning of the northern autumn and winter and in spring and early summer. The succulent stemmed species may be sent at any time but plants are usually in peak condition in the southern autumn, winter and early spring. This is the preferred time for the nursery to send out orders.

PHOTOGRAPHS OF OTHONNAS OFFERED BY PENROCK NURSERY.
Please click here if you would like to view photographs of various Othonna species offered by Penrock Nursery. The photographs feature plants at the beginning of the growing season, when they start to sprout leaves, and also when they are in full leaf and flower.

Othonna retrofracta found near Robertson and Worcester in the Western Cape has the unusual characteristic of having large rounded caudexes. It is well suited to cultivation and like other othonnas is winter growing.

Some of the Othonna species with ornamental stems look at their best when in the leafless state, particularly species with masses of tubercles such as Othonna herrei. Photographs of these Othonna species are also included.

Othonnas lend themselves to planting in specially hand made terracotta containers with a rough finish. Several such plants are featured amongst the selection of photographs.