Osyris compressa
Encyclopedia
Osyris
compressa (Cape Sumach or Pruimbos) is a facultatively
hemiparasitic
, mainly South Africa
n plant of the Sandalwood
family, Santalaceae
. Until recently the favoured binomial name
was Colpoon compressum, but the genus Colpoon was included in Osyris
on the basis of comparative DNA studies.
, blue-green with a greyish bloom, elliptical
, smooth, stiff, typically about 20-50mm long, with thickened, entire margins. The inflorescence is a terminal panicle
, bearing small, slightly fragrant, bisexual flowers. The flowers are creamy-green and unspectacular, but they appear through much of the year, attracting pollinating insects of various types. The ovary has 4 ovules, but the fruit is a single-seeded drupe, a prolate spheroid
in shape. In size it is about 15 mm to 25 mm long and perhaps 10 mm to 15 mm across. The drupe is fleshy with a smooth skin crowned with the perianth
lobes in a ring around its tip. Usually by the time the fruit is ripe, a circular groove is all that remains of the perianth. The fruit are colourful, progressing first from greenish blue to bright red, and then to glossy purple or black as they ripen; they mature at different rates, so the successive colours can be quite showy in combination.
The species is mainly South Africa
n, occurring from the coastal fynbos in the region of the Cape Peninsula
in the west, along the south coast and up into tropical East Africa.
, and both cross-pollinating
and self-fertile
, the species produces fertile seeds prolifically. It begins to bear fruit when quite young, and it seeds plentifully practically throughout the year. The fruit attracts a range of birds and mammals that spread the seed effectively.
Osyris compressa, like many members of the family Santalaceae, exploit a facultative
hemiparasitic
ecological strategy to supplement their nutrient supplies, especially in dry conditions or poor soils. Their roots form haustoria
that tap into the roots of nearby plants and extract their sap. Although Osyris compressa plants can grow without a host, this habit helps them to flourish in relatively poor coastal sands, and they need hosts if they are to grow at their best. In this respect Osyris compressa resembles some other hemiparasites in related families such as Nuytsia floribunda in the Loranthaceae
.
Being itself parasitic does not protect Osyris compressa from other parasites; several species of mistletoe
in the genus Viscum
(currently recognised as members of the same family as Osyris, namely Santalaceae) often parasitise its branches. Also, given that Osyris compressa is itself a root parasite, it is interesting to note that it in turn may be host to another root parasite in the same family, namely Thesidium fragile and possibly related species. It is not clear which, if either, of these rival root parasites benefits from the other when their roots meet.
Being a densely-leaved shrub with plentiful, if inconspicuous, flowers and edible fruit, Osyris compressa is of importance as a shelter and food plant for many animals. Of these probably the best-known is the butterfly Mylothris agathina
, a member of the family Pieridae
. Its common name is "Eastern Dotted Border" or "Common Dotted Border". Osyris compressa is not the only food plant for Mylothris agathina
, but probably the most important in some regions.
birds.
Osyris compressa has been grown in programs to stabilize coastal dunes.
The leaves and bark used to be valued for tanning. The wood is high-quality and fine-grained, but the plant seldom produces trunks or limbs large enough for most uses. Although there does not seem to be much active cultivation of the plant, it seems to be of interest as a source of incense and essential oil in much the same way as sandalwood.
The flesh of the berries is edible and formed part of the diet of the local Khoikhoi
, both fresh and preserved as the dried pulp. It shows little promise as a popular fruit for westerners however, having a "tingly sour taste", according to some reports. Others however describe it as "plum-like", and the Afrikaans name "pruimbos" means "plum bush".
An extract from the boiled bark has been used to flavour tea.
Osyris compressa can be propagated by seed.
Osyris
Osyris is a genus of plants in the family, Santalaceae, one of the many genera known as Sandalwoods.The species of this genus are mostly hemi-parasitic, meaning that although they can survive and grow by themselves, they will also opportunistically tap into the root systems of nearby plants and...
compressa (Cape Sumach or Pruimbos) is a facultatively
Parasitic plant
A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...
hemiparasitic
Parasitic plant
A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...
, mainly South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
n plant of the Sandalwood
Sandalwood
Sandalwood is the name of a class of fragrant woods from trees in the genus Santalum. The woods are heavy, yellow, and fine-grained, and unlike many other aromatic woods they retain their fragrance for decades. As well as using the harvested and cut wood in-situ, essential oils are also extracted...
family, Santalaceae
Santalaceae
Santalaceae is a widely distributed family of flowering plants which, like other members of Santalales, are partially parasitic on other plants...
. Until recently the favoured binomial name
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
was Colpoon compressum, but the genus Colpoon was included in Osyris
Osyris
Osyris is a genus of plants in the family, Santalaceae, one of the many genera known as Sandalwoods.The species of this genus are mostly hemi-parasitic, meaning that although they can survive and grow by themselves, they will also opportunistically tap into the root systems of nearby plants and...
on the basis of comparative DNA studies.
Distribution and Description
Osyris compressa is a shrub or small tree of up to 5 metres tall, though a more typical size for a plant growing in the open would be 2 or 3 metres. The leaves are opposite, decussateDecussation
Decussation is used in biological contexts to describe a crossing.Examples include:* In the brain, where nerve fibers obliquely cross from one lateral part to the other, that is to say they cross at a level other than their origin...
, blue-green with a greyish bloom, elliptical
Leaf shape
In botany, leaf shape is characterised with the following terms :* Acicular : Slender and pointed, needle-like* Acuminate : Tapering to a long point...
, smooth, stiff, typically about 20-50mm long, with thickened, entire margins. The inflorescence is a terminal panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....
, bearing small, slightly fragrant, bisexual flowers. The flowers are creamy-green and unspectacular, but they appear through much of the year, attracting pollinating insects of various types. The ovary has 4 ovules, but the fruit is a single-seeded drupe, a prolate spheroid
Prolate spheroid
A prolate spheroid is a spheroid in which the polar axis is greater than the equatorial diameter. Prolate spheroids stand in contrast to oblate spheroids...
in shape. In size it is about 15 mm to 25 mm long and perhaps 10 mm to 15 mm across. The drupe is fleshy with a smooth skin crowned with the perianth
Petal
Petals are modified leaves that surround the reproductive parts of flowers. They often are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are usually accompanied by another set of special leaves called sepals lying...
lobes in a ring around its tip. Usually by the time the fruit is ripe, a circular groove is all that remains of the perianth. The fruit are colourful, progressing first from greenish blue to bright red, and then to glossy purple or black as they ripen; they mature at different rates, so the successive colours can be quite showy in combination.
The species is mainly South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
n, occurring from the coastal fynbos in the region of the Cape Peninsula
Cape Peninsula
The Cape Peninsula is a generally rocky peninsula that juts out for 75 km into the Atlantic Ocean at the south-western extremity of the African continent. At the southern end of the peninsula are Cape Point and the Cape of Good Hope...
in the west, along the south coast and up into tropical East Africa.
Reproduction and ecology
Osyris compressa is a tough and adaptable plant. It can withstand frost, heat and winds. It grows fast and survives in poor sandy soils, even in coastal dunes, where it may play a significant role as a windbreak and in binding sand. Being monoecious, and with bisexual flowersPlant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
, and both cross-pollinating
Allogamy
Allogamy is a term used in the field of biological reproduction describing the fertilization of an ovum from one individual with the spermatozoa of another. By contrast, autogamy is the term used for self-fertilization. In humans, the fertilization event is an instance of allogamy...
and self-fertile
Plant sexuality
Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....
, the species produces fertile seeds prolifically. It begins to bear fruit when quite young, and it seeds plentifully practically throughout the year. The fruit attracts a range of birds and mammals that spread the seed effectively.
Osyris compressa, like many members of the family Santalaceae, exploit a facultative
Parasitic plant
A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...
hemiparasitic
Parasitic plant
A parasitic plant is one that derives some or all of its sustenance from another plant. About 4,100 species in approximately 19 families of flowering plants are known. Parasitic plants have a modified root, the haustorium, that penetrates the host plant and connects to the xylem, phloem, or...
ecological strategy to supplement their nutrient supplies, especially in dry conditions or poor soils. Their roots form haustoria
Haustorium
In botany, a haustorium is the appendage or portion of a parasitic fungus or of the root of a parasitic plant that penetrates the host's tissue and draws nutrients from it. Haustoria do not penetrate the host's cell membranes.Fungi in all major divisions form haustoria...
that tap into the roots of nearby plants and extract their sap. Although Osyris compressa plants can grow without a host, this habit helps them to flourish in relatively poor coastal sands, and they need hosts if they are to grow at their best. In this respect Osyris compressa resembles some other hemiparasites in related families such as Nuytsia floribunda in the Loranthaceae
Loranthaceae
Loranthaceae is a family of flowering plants, which has been universally recognized by taxonomists. It consists of about 75 genera and 1,000 species of woody plants, many of them hemi-parasites, all of them except three having the mistletoe habit...
.
Being itself parasitic does not protect Osyris compressa from other parasites; several species of mistletoe
Viscum
Viscum is a genus of about 70-100 species of mistletoes, native to temperate and tropical regions of Europe, Africa, Asia and Australasia. Traditionally, the genus has been placed in its own family Viscaceae, but recent genetic research by the Angiosperm Phylogeny Group shows this family to be...
in the genus Viscum
Viscum
Viscum is a genus of about 70-100 species of mistletoes, native to temperate and tropical regions of Europe, Africa, Asia and Australasia. Traditionally, the genus has been placed in its own family Viscaceae, but recent genetic research by the Angiosperm Phylogeny Group shows this family to be...
(currently recognised as members of the same family as Osyris, namely Santalaceae) often parasitise its branches. Also, given that Osyris compressa is itself a root parasite, it is interesting to note that it in turn may be host to another root parasite in the same family, namely Thesidium fragile and possibly related species. It is not clear which, if either, of these rival root parasites benefits from the other when their roots meet.
Being a densely-leaved shrub with plentiful, if inconspicuous, flowers and edible fruit, Osyris compressa is of importance as a shelter and food plant for many animals. Of these probably the best-known is the butterfly Mylothris agathina
Mylothris agathina
The Eastern Dotted Border or Common Dotted Border is a butterfly of the Pieridae family. It is found in Mozambique, Zimbabwe, Botswana and southern and eastern South Africa...
, a member of the family Pieridae
Pieridae
The Pieridae are a large family of butterflies with about 76 genera containing approximately 1,100 species, mostly from tropical Africa and Asia. Most pierid butterflies are white, yellow or orange in coloration, often with black spots...
. Its common name is "Eastern Dotted Border" or "Common Dotted Border". Osyris compressa is not the only food plant for Mylothris agathina
Mylothris agathina
The Eastern Dotted Border or Common Dotted Border is a butterfly of the Pieridae family. It is found in Mozambique, Zimbabwe, Botswana and southern and eastern South Africa...
, but probably the most important in some regions.
Cultivation of Osyris compressa
This plant is popular in coastal gardens as an ornamental. It grows in coastal dunes and because of its vigorous and compact growth habit, it can be shaped into a dense hedge. It also produces attractive multi-coloured berries throughout the year that are ornamental in themselves and attract frugivorousFrugivore
A frugivore is a fruit eater. It can be any type of herbivore or omnivore where fruit is a preferred food type. Because approximately 20% of all mammalian herbivores also eat fruit, frugivory is considered to be common among mammals. Since frugivores eat a lot of fruit they are highly dependent...
birds.
Osyris compressa has been grown in programs to stabilize coastal dunes.
The leaves and bark used to be valued for tanning. The wood is high-quality and fine-grained, but the plant seldom produces trunks or limbs large enough for most uses. Although there does not seem to be much active cultivation of the plant, it seems to be of interest as a source of incense and essential oil in much the same way as sandalwood.
The flesh of the berries is edible and formed part of the diet of the local Khoikhoi
Khoikhoi
The Khoikhoi or Khoi, in standardised Khoekhoe/Nama orthography spelled Khoekhoe, are a historical division of the Khoisan ethnic group, the native people of southwestern Africa, closely related to the Bushmen . They had lived in southern Africa since the 5th century AD...
, both fresh and preserved as the dried pulp. It shows little promise as a popular fruit for westerners however, having a "tingly sour taste", according to some reports. Others however describe it as "plum-like", and the Afrikaans name "pruimbos" means "plum bush".
An extract from the boiled bark has been used to flavour tea.
Osyris compressa can be propagated by seed.