
This decorative shrub with dainty, small white flowers and sweet,
honey smell make this buchu an ideal garden plant and interesting
specimen for floral arrangements.
Description
Coleonema album an erect, much-branched and compact shrub
grows to a height of 2 m. This fragrant buchu is finely branched
and new shoots develop at the tips of old branches. Branching occurs
from the base of the shrub. Bark is greyish-brown, rough with horizontal
leaf scars. The inflorescence is solitary, axillary and crowded
at the branch tips. Closed flower buds are pinkish tinged and appear
white when open. Flowers are small, white, 6-7 mm in diameter with
a dark green disc at the centre. Crowded at the branch tips are
5-11 blooms. The flowers are carried in such profusion that the
bush is a cloud of white when in flower and attracts bees and butterflies.
It flowers from May to November.
Leaves are needle-like / linear-oblong are 12-13.5 mm x 1.3-1.5
mm broad. Oil glands are visible on the reverse side of the leaves.
The leaves when crushed have a characteristic sweet smell. Ripe
fruits may be found up to end of November. The fruit is 5-lobed
and ripe seed are ejected by a catapult mechanism. Regeneration
takes place from seed.
Distribution
Coleonema album occurs from Saldanha Bay to the Cape Peninsula
and as far east as Bredasdorp.
This
buchu appears to be very much a coastal plant, able to withstand
strong coastal winds. The only population at any great distance
from the sea lies at the southern end of the Bredasdorp Mountains
about 19 km from the sea. Plants are found growing amongst outcrops
of rocks of the Table Mountain Sandstone series or of the underlying
Cape granite, but never on the coastal limestone of the Bredasdorp
Series. Plants grow at sea level and up to a maximum altitude of
750 m on Table Mountain.
Derivation of name and horticultural aspects
From the Greek koleos, sheath, and nema, thread /
filament. The filaments of the sterile stamens are enfolded in the
channel of petals.
There are eight species found in the genus Coleonema, which
occur in Western Cape and Eastern Cape. This genus belongs to the
Rutaceae family also known as the citrus family. The confetti bush,
Coleonema pulchellum, an erect shrub, 800 mm -1 m in height,
bears pink flowers from May to October, also belongs to this genus,
as does C.aspalathoides.
Ecology
The conspicuous white flowers and the nectariferous disc indicate
that pollination is most probably effected by insects.
Uses and cultural aspects
It is an excellent coastal plant and can be used as a topiary specimen.
The aromatic leaves containing essential oils are used by fishermen
to remove the odour of redbait (aas) from their hands, hence the
common name.
Campers rub the leaves onto their bedding to keep ants and mosquitoes
away. The leaves are used in potpourri and act as an insect repellant.
Growing Coleonema album
Coleonema
album can be used as an accent plant in the garden, a hedge
plant or as a filler plant in a mixed fynbos bed with companion
plants such as Erica, Restio, Protea, buchu, herbaceous perennials
such as Geranium incanum, Felicia aethiopica, Scabiosa
incisa, and shrubs such as Salvia species, Metalasia muricata,
Euryops virgineus. It is also an ideal container plant for a
sunny position on a stoep or patio.
This species requires full sun and soil that is acid, well drained
and composted. Add a layer of mulch to keep the soil and roots cool
in summer, retain soil moisture and reduce weeds. Buchus are best
planted out during the winter-spring season. Plants require good
watering in winter and moderate watering in summer. Do not allow
plants to dry out. Once established in your garden they will survive
long periods of drought.
Coleonema album is easily grown from seed. Fresh seed is
collected from the previous year's flowers and stored in brown paper
bags upon ripening. The optimum time for sowing is during autumn.
Seed are cleaned and sown on a prepared medium of sand and compost
in equal parts in a seed tray. Cover seed with a thin layer of bark
and water. Place seed trays in a covered area with good light and
ventilation. Keep seed trays damp and germination will take place
within 1 to 2 months. Seedlings are pricked out when 4 true leaves
have developed. The growing tips of seedlings are pinched out to
encourage bushy growth. Feed buchus regularly with a balanced nutrient
Cuttings have the advantage of producing a larger flowering plant
quicker than seedlings. Tip cuttings, 50-70 mm, are taken from the
current year's growth from August to October. Prepare cuttings by
making a clean cut below the node and remove a third of the foliage.
Dip the base of the cutting in a rooting hormone. Firmly place the
cuttings in a medium of 50 % bark and 50 % polystyrene. Ideally
these cuttings should now be placed in a well-aerated propagation
unit with a bottom heat of 24°C. Rooting occurs in 9 to 11 weeks.
Carefully pot the rooted cuttings using a well-drained humus riched
fynbos-potting medium (2 parts leafmould, 1 part coarse sand). Plants
will be ready for planting in 7 to 8 months. Feed regularly with
a well-balanced nutrient. Yellow leaves can be treated with an application
of iron chelate.

Coleonema album vs Coleonema calycinum.
These two species can easily be confused. C. calycinum grows
to a height of over 2 m and also bears white flowers from September
to October. It occurs naturally on mountain slopes near Worcester
and from Caledon to Bredasdorp (limestone hills).
Coleonema album
Coleonema album may be distinguished from all other
species by having:
- Staminode mostly connate with the petal
- Flowers white, 6-7 mm diameter
- Leaves 12-13,5 mm long. The presence of a small conelike
gall, found only in this species, is a useful character
for identification.
- Grows to a height of 2m.
- Sweet-scented
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Coleonema calycinum
Coleonema calycinum identified by the following:
- Leaves 13-19mm long, 0,7-1mm broad
- Calyx lobes 1,2mm long
- Flowers 5,5-6,5mm diameter, flower buds are pink, flowers
white when open.
- Grows to a height of over 2m.
- Petals obtuse (rounded or blunt) and staminode connate
(having similar parts joined by growth) with petal in the
lower half.
- Rum-scented
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References
- MASON, H. 1972. Western Cape Sandveld Flowers. Struik
Publishers, Cape Town.
- LEVYNS. M.R. 1966. Guide to the flora of Cape Peninsula.
Juta and Company, Limited, Wynberg.
- GOLD, M. 1992. The Buchus Cultivation and Propagation.
National Botanical Institute, Kirstenbosch
- GOLDBLATT, P. & MANNING, J. 2000. Cape Plants, A conspectus
of the Cape Flora of South Africa Strelitzia 9. National
Botanical Institute, Pretoria & Missouri Botanical Garden,
Missouri.
Norma Jodamus
Horticulturist, Kirstenbosch National Botanical Garden
September 2003
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