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Gethyllis, a genus of the family Amaryllidaceae, has such
unusual foliage, flowers and fruits that it ranks as one of the
most fascinating groups of bulbous plants in southern Africa.
Description
The name Gethyllis is thought to come from the Greek gethyon,
which means a bulb, onion or species of leek. The apparent likeness
to a leak is due to the bulbs' long, white sheathing tunics that
surround the base of the leaves, rather than to the plants' culinary
properties.
Gethyllis,
like most other plants adapted to temperate climates, is deciduous.
Nourished by long, fleshy roots, the bulbs store sufficient reserves
to survive the long, dry season in a dormant state but when conditions
become favourable they produce leaves.
Most species have a basal cluster of numerous, narrow, frequently
spiralled leaves, whereas a few have only 1 or 2 leaves, which are
broad and held flat on the ground. Several species are easily recognized
by a prominent sheath that extends above ground and holds the leaves
in a tight cluster. The sheaths themselves are often attractively
ornamented with handsome reddish brown spots (e.g. G. britteniana)
or they are elaborately fringed, as in G. verticillata. Unlike
most Amaryllidaceae, the leaves of Gethyllis are often hairy.
The hairs are simple and evenly spaced or T-shaped and clustered
together, which adds to the density of the covering.
Gethyllis
differs from most of its relatives by having just one flower
per bulb each season. Each flower has 6 tepals, which join to form
a long floral tube that leads down to a subterranean ovary. The
flowers vary from white to cream or pink and the tepals are often
boldly striped with dark pink. Generally they are sweetly and strongly
scented. Equally attractive are the prominent, bright yellow anthers,
which help to distinguish groups of species. For instance, G.
ciliaris and its relatives may have as many as 30 anthers per
flower, whereas G. verticillata and its allies only have
6 anthers per flower as is typical of most Amaryllidaceae. Although
initially long and straight, the anthers eventually curl up, becoming
less conspicuous with age. The style is noticeably variable in its
length and position. It is straight and stout, terminating in a
small, undifferentiated stigma, or slender and curved with a conspicuous,
broad stigma at its tip.
The berry-like, finger-length fruits are borne close to the ground
and are variously shaped, coloured and fragrant when ripe. Best
known are the fleshy, yellow to pink fruits which smell somewhat
of strawberries. Less conspicuous are the slender, thin-textured
fruits that remain pale-coloured, sometimes spotted, and odourless.
When ripe, the fruit walls disintegrate and release numerous, roundish,
cream-coloured to reddish seeds. The basic chromosome number for
the genus is x = 6.
Distribution
Gethyllis has 32 recognized species, 30 of which are found
in the summer-arid areas of southern Africa. Only G. transkarooica
and G. longistyla are found in the summer-rainfall region's
Nama Karoo Biome. The greatest number of species occurs in the Succulent
Karoo Biome, followed by the Fynbos Biome. Habitats range from coastal
forelands to South Africa's high-lying, inland plateau. In most
instances the plants prefer open sites, free of competition from
shrubs and grasses. The majority of species favours semi-arid habitats
but a few Cape species (G. afra and G. kaapensis)
are localized in seasonally moist sites amongst lowland fynbos vegetation.
Ecology
To cope with their dry environments these plants have developed
a remarkably novel lifestyle. They flower fleetingly in midsummer,
fruit in autumn, and have leaves in winter, a period when they are
most likely to be seen before conditions dry out at the end of spring.
Studies suggest that the fleshy seeds evolved early in the group's
history and greatly influenced the group's evolution when conditions
in southern Africa became more arid several million years ago.
The seeds germinate immediately once released, but for the seedlings
to survive, they depend on adequate and timely rainfall. In the
western and northwestern Cape, the optimal time for seed release
is autumn. The large, many-seeded fruits are slow to mature, so
flowering is bound to take place several months earlier, in midsummer.
To cope with the dry summer conditions, flowering lasts two or three
days and is synchronous. In addition, the ovary, which later becomes
the fruit, remains cool and protected below ground, where it continues
to ripen for several months.
The pollination of Gethyllis has not yet been thoroughly
researched but the idea that moths pollinate the fragrant flowers
seems unlikely as the entrance to the long floral tube is almost
completely blocked by the style. The main pollinators are probably
bees, drawn to the huge amount of pollen in the large, often multiple
anthers.
Tortoises, birds and rodents are said to eat the fruit's fleshy
pulp and act as agents for seed dispersal but this remains unconfirmed.
Instead, the presence of plants in clumps suggests that the seeds
drop directly next to the mother plant, allowing the seedlings to
remain in habitats that have favoured survival in the past.
The significance of the tightly spiralled leaves is not fully understood,
but the compact arrangement may prevent water loss, especially when
combined with a hairy covering. These features are evident in G.
villosa, a widespread species in the semi-arid areas of the
western and northwestern Cape.
Economic and cultural value
The fruits are much sought after for their fragrance and purported
medicinal properties. In the past the dried fruits were often used
to scent handkerchiefs and linen cupboards. A dilute infusion of
the flowers of G. spiralis was used to ease teething troubles
and its skin was applied to boils, bruises and insect bites. Today
the edible fruits of G. afra are still used to make kukumakranka
brandy, a popular remedy for colic and indigestion.
Species
Although many Gethyllis species are rare, the following species
are more commonly seen in the wild:
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G. afra L. Plants 100-140 mm high. Leaves
12-30, linear, erect to spreading, spiralled, usually channelled,
occasionally with simple, soft spreading hairs on one or both
surfaces or the margin. Flower cup-shaped, white with pink reverse,
tepals 20-35 mm long, anthers 9-18 in clusters of 6, style straight,
as long as the stamens, stigma small. Berry club-shaped, fleshy,
yellow to red. Flowering time: December to January. Lowland
flats in fynbos from Clanwilliam to Heidelberg. |
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G. ciliaris (Thunb.) Thunb. Plants often
forming clumps, 150-300 mm high. Leaves 15-25, narrowly strap-shaped,
spiralled, firm, shiny green, the margins fringed with rigid,
upturned hairs, the basal sheath 1, mostly subterranean, pale,
spotted with maroon when exposed. Flower cup-shaped, ivory to
deep pink, waxy, tepals 30-70 mm long, anthers 15-31 in 6 clusters,
style straight and stout, stigma narrowly trifid. Berry club-shaped,
yellow. Flowering time: December to February. Coastal forelands
in deep sand, southern Namaqualand, Nardouwsberg to Cape Peninsula. |
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G. villosa (Thunb.) Thunb. Plants 30-150
mm high, sometimes clumped. Leaves 4-12, narrow and tapering
to each end, spreading, loosely spiralled towards the apex,
more or less covered with soft, white, T-shaped hairs, the margin
and apex often with dense, firm, compound hairs. Flower white
or pink, tepals 20-40 mm long, anthers 6, style longer than
the stamens, curved sideways, stigma broadly 3-lobed. Berry
slender, cylindrical, membranous, white with red seeds. Flowering
time: October to December. In sand or clay on flats or south-facing
slopes, Namaqualand to Mossel Bay and western Karoo. |
In the Garden
As the bulbs die easily if over-watered, the cultivation of Gethyllis
is best left to a bulb specialist and their use in gardens should
be avoided. The bulbs grow best in deep containers in a well-drained
medium. Water should be applied with restraint in winter but stopped
as soon as the leaves begin to wither in spring, when the pots should
be moved to a cool, dry place.
References and further reading
- Du Plessis, N. & Duncan, G. 1989. Bulbous plants of southern
Africa. Tafelberg, Cape Town.
- Jackson, W.P.U. 1987. Origins and meanings of names of South
African plant genera. Botanical Society of South Africa, Kirstenbosch,
Cape Town.
- Leistner, O.A. (ed.). 2000. Seed plants of southern Africa:
families and genera. Strelitzia 10. National Botanical
Institute, Pretoria.
- Manning, J., Goldblatt, P. & Snijman, D. 2002. The color
encyclopedia of Cape bulbs. Timber Press, Portland, Cambridge.
- Smith, C.A. 1966. Common names of South African plants. Memoirs
of the Botanical Survey of South Africa No. 35. Department
of Agricultural Technical Services, Pretoria.
- Watt, J.M. & Breyer-Brandwijk, M.G. 1962. The medicinal
and poisonous plants of southern Africa and eastern Africa.
Livingstone, Edinburgh and London.
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Author
Dee Snijman
Compton Herbarium, Kirstenbosch
July 2004
Images
Colin Paterson - Jones
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