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Scilla natalensis is a graceful perennial bulb, and with
its tall plumes of blue flowers, the showiest of the South African
scillas. It is a variable species, with individuals and populations
of differing bulb size, flower colour, leaf coloration etc. In general
it produces a large bulb, 10 to 15 cm in diameter, covered with
firm, hardened, papery brown or purplish tunics (bulb scales). It
is deciduous, growing during summer and dormant in the winter.
A
rosette of 6 to 9 broad, tapering leaves emerges from the top of
the bulb in spring. The leaves are attractive in their own right,
with clearly distinct veins which give them a two-tone effect, particularly
when back-lit. Their colour is light green with white-grey overtones,
they can be entirely green, or they can have purplish colouring
on the margins, at the base or at the apex of the leaf, or the underside
can be partially or entirely shaded with purple. They can be completely
hairless, or one or both sides can be covered in short hairs. The
leaves of a well-grown plant can reach a height of 30 to 50 cm with
about equal spread.
The
inflorescence is a many-flowered slender raceme of bright violet-blue,
or pale blue, or blue and white, star-shaped flowers each one carried
on a delicate amethyst blue stalk, giving the overall effect of
a misty blue plume floating in mid-air. There is also a white form,
although we don't have specimens in the Garden as yet. The flower
stalks are produced either just before or with the new leaves in
spring to early summer (October), and are usually about 1 m tall,
although some are as short as 0.75 m and a few can reach a height
of about 1.4 m. The flowers have a honey-like scent towards evening
and are visited by bees during the day. The seed, which is formed
in capsules that split when mature, does not look much like seed.
It is beige in colour, somewhat irregular in shape and a bit wrinkled,
6 mm long x 2-3mm wide tapering to a point. It is light in weight
and dispersed by the wind. It does not last long unless it is refrigerated
(not frozen) where it will last for a number of years.
Scilla natalensis occurs on the east of southern Africa,
throughout the Eastern Cape, Lesotho, KwaZulu-Natal, Free State,
Swaziland and into Mpumalanga where it is found growing in a variety
of habitats from sunny slopes, rocky hills, cliffs and ledges, to
damp cliff faces, near waterfalls, in moist depressions, on the
edges of streams and vleis (wetlands) to coastal areas, in groups
or as solitary specimens. It's Red Data conservation status has
recently been upgraded from Insufficiently Known to Vulnerable due
to its being a very popular item in the KwaZulu-Natal muthi trade.
Intensive harvesting is causing a decline in wild populations over
an ever-increasing area of its distribution range.
Scilla natalensis has shown itself to be selectively toxic
to mammals. It is said to be poisonous to stock, particularly when
the young leaves appear in spring. Experiments on sheep, using fresh
bulb as a drench, proved fatal to the sheep, yet it has been proven
an ineffective rat poison. It is apparently toxic to man when raw,
even the sap is reported to burn the skin, and for any preparations
taken internally the plant must first be heated.
This plant should be treated with extreme caution, as taking any
part of it internally is potentially fatal. The bulb is used
medicinally in South Africa and is one of the most popularly traded
muthi (meaning traditional medicine and pronounced moo-tea) items
in KwaZulu-Natal. Warmed fresh bulb scales, slightly burned bulb
scales and decoctions of the bulb are used externally as ointments
for wound-healing, to treat sprains, fractures, boils and sores
and to draw abscesses. The ash from a burnt plant, and the bulb
in powdered form, is rubbed into cuts and scratches, and over sprains
and fractures. Decoctions are taken as enemas for female infertility
and to enhance male potency and libido. It is also known to be used
as a purgative, a laxative and for internal tumours, and is used
in conjunction with other ingredients in infusions taken during
pregnancy to facilitate delivery and in treatments for chest pain
and kidney troubles. It is also an ingredient in a medicinal preparation
for cattle suffering from lung sickness. It has magical properties
for the Tswana who rub the powdered bulb into the back, joints and
other body parts to increase their strength and resistance to witchcraft.
The plant appears to have significant analgesic and antimicrobial
activity, and phytochemical studies have found that it contains
compounds known to possess anti-inflammatory and anti-mutagenic
properties which would support its use for the treatment of strains,
sprains and cancers. Although its effect on sheep appears similar
to that caused by cardiac glycoside poisoning, whether or not it
contains the same heart glycosides found in the closely related
genera of Drimia and Urginea remains to be determined.
The genus name Scilla is the ancient Greek and Latin name
for Urginea maritima now called Drimia maritima, the
sea squill. It could also be derived from the Greek skyllo meaning
"I injure" referring to the poisonous bulbs. The medicinal
squill containing active cardiac glycosides, was obtained from other
species of Urginea and Drimia. The genus name natalensis
means pertaining to Natal, now KwaZulu-Natal (Latin) and refers
to the region where it was first found. The Afrikaans name blouberglelie,
which means blue mountain lily, is also applied to other South African
species of Scilla and is a name that has been in use for
hundreds of years. It earned the name blouslangkop, which means
blue snake's head, presumably because the emerging flower stalk
resembles a snake, and the tips of the flower stalks are often coloured
bluish-purple. The Zulu name inguduza means "searching the
body for the cause of the ailment", indicating its use in KwaZulu-Natal
as a diagnostic tool.
Scilla natalensis belongs in the family Hyacinthaceae (hyacinth
family), formerly part of the Liliaceae (lily family), a family
of perennial bulbous herbs consisting of ±46 genera and ±900
species found in Africa, Eurasia and North America but most richly
represented in southern Africa and in the Mediterranean region to
south west Asia. Other noteworthy southern African members of this
family include Veltheimia bracteata, Lachenalia mathewsii, Eucomis
species (pineapple lilies) and Ornithogalum species (chinkerinchees)
while species more familiar to northern hemisphere gardeners include
the hyacinth, Hyacinthus orientalis and the bluebell, Hyacinthoides
non-scripta. The genus Scilla consists of ±40
species, with 6 in southern Africa and the others occurring in the
rest of Africa, Europe and Asia. There has been a lot of synonymy
but the current list of recognised species in southern Africa includes:
Scilla dracomontana, S. firmifolia, S. kraussii, S. natalensis,
S. nervosa and S. plumbea.
Growing Scilla natalensis
This
is an easy plant in cultivation and is ideally suited to the rockery
but will do equally well in a container. It can also be used to
good effect planted in clumps or drifts in the mixed border. Each
individual flower is not long-lasting, but there are so many of
them opening in succession that the inflorescence will last for
up to a month in the garden, and it is a useful cut flower. It requires
a sunny or semi-shaded position, in good, compost (humus) enriched,
well-drained soil. Plants in bags/pots can be planted at any time
of the year, and bare-rooted bulbs are best planted whilst still
dormant in late winter to early spring. The bulbs should be planted
with at least two-thirds to one half showing above ground. It is
best to leave them undisturbed for as long as possible, as they
take a season or two to settle down and flower again after being
moved. A general-purpose granular fertiliser can be used periodically
during the growing season, and the plants will benefit from mulching
throughout the year. They are relatively drought tolerant, but to
grow well they require ample water in summer. As the leaves start
to yellow in late summer to autumn, water can be withheld. It is
best to keep them dry during winter, but they are undamaged by the
wet Cape Town winters provided the soil is well-drained or they
are growing on sloping ground. Scilla natalensis can be considered
frost hardy to zone 9 (-7 °C / 20 °F) but in severely cold climates
it is probably best grown in containers which can be taken indoors
during winter, or grown in a glasshouse.
Propagation is by seed or division of offsets.
Seed germinates readily, but it must be noted that it does not last
long unless it is refrigerated. It can be sown immediately after
harvest in summer, or the previous season's refrigerated seed can
be sown in spring or summer. Germination occurs within 7 days and
the plants should flower in their third or fourth year. Again it
is recommended that the young plants be disturbed as little as possible
in order to get them to flower as soon as possible, so sow the seed
thinly in deep (minimum 10cm) trays or pots, or transplant them
into larger individual pots/bags after thinning the seed trays,
or during their second season.
Offsets (daughter bulbs) are produced at the base of a mature bulb
and can be removed and replanted during the dormant period. If left
undisturbed a single plant will in time become a clump of plants
which can be lifted and divided during the dormant period, or the
outer ones can be detached without lifting the entire clump. When
dividing two bulbs it may be necessary to cut them apart. Dust the
cut surface with a fungicide and store for at least 2-3 weeks in
a cool dry spot to allow a seal to form over the wound. The divided
bulbs can then be planted as described earlier.
References:
- Douwes, E., Crouch, N.R., Symmonds, R., 2001, Blue Squill in
the Red: Scilla natalensis as a Conservation Charge, PlantLife,
24 (14-19).
- Du Plessis, N., & Duncan, G., 1989, Bulbous Plants of Southern
Africa, A guide to their Cultivation and Propagation, Tafelberg,
Cape Town.
- Jackson, W.P.U., 1990, Origins and Meanings of Names of South
African Plant Genera, U.C.T. Printing Dept., Cape Town.
- Jeppe, B., 1975, Natal Wild Flowers, Purnell, Cape Town
- Leistner, O.A. (ed.), 2000, Seed plants of southern Africa:
families and genera, Strelitzia 10., National Botanical Institute,
Pretoria.
- Smith, C.A., 1966, Common Names of South African Plants, Dept.
of Agricultural, Botanical Survey Memoir No 35, Government Printer.
- van Wyk, B.E., van Oudtshoorn, B., Gericke, N., 1997, Medicinal
Plants of South Africa, Briza Publications, Pretoria, South Africa.
Alice Notten
Kirstenbosch NBG
October 2001
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