Agapanthus

Agapanthus praecox Willd.

Synonyms -

Family: Agapanthaceae (was Amaryllidaceae)

Names:

Other Names

African Lily

Summary:

Agapanthus is a rhizomatous perennial herb with a large basal tuft of dark green shiny leaves. The leaves are linear, strap-like and somewhat arching, 20-80 cm long x 2-6 cm wide. The blue to purple or white flowers are clustered in a large globular flower head, 10-15 cm across, which is held high above the leaves on a stout shiny stalk to 1 m high. The individual flowers have 6 petals, 4-6 mm long and 6 stamens. The fruit is a greenish capsule. Old plants have a thick branched underground stem.
Native to South Africa, Agapanthus is a common garden plant and has become a weed of high rainfall areas along roadsides particularly near settlements, urban bushland and granite outcrops. It flowers in spring and summer.

Description:

Cotyledons:

One.

First leaves:

Leaves:

Up to 20 leaves arise from the base of the plant.
Blade - Dark green, strap like, leathery, arching, 200-800 mm long x 20-60 mm wide with watery sap. Surface shiny and hairless. Tip pointed. Edges parallel. Base sheathing.
Ligule - None
Auricles - None
Sheath - Sheathing base.

Stem leaves - None.

Stems:

Stemless, but has underground rhizomes.
Flower stem - Cylindrical, hollow, leafless, up to 1000 mm tall

Flower head:

Single, many-flowered umbrella or ball like cluster, about 70-150 mm diameter x 50-100 mm deep. 2 large bracts enclose the immature flower head.

Flowers:

Purple-blue or white, tubular and small in clusters. Bisexual. Each flower on a 50-80 mm long stalk.
Ovary - 3 Carpels.
Style - Slender.
Petals - 6. 40-60 mm long and fused towards the base. Purplish-blue and often somewhat striped or occasionally white.
Stamens - 6. Thread-like, 40-45 mm long.
Anthers - 6. Oblong.

Fruit:

3 celled capsule. Greenish turning light brown to greyish with age.

Seeds:

Black, thin and papery.

Roots:

Rhizomes that are thick, long and white and there are many-branched, shallow feeder roots.

Key Characters:

Biology:

Life cycle:

Perennial. Flowers in summer.

Physiology:

Reproduction:

By seed and vegetatively by rhizomes.

Flowering times:

November to January in WA.
December to February in NZ.

Seed Biology and Germination:

Vegetative Propagules:

Rhizomes.

Hybrids:

At least 2 sub species are recognised; A. praecox ssp. orientalis and A. praecox ssp. praecox.
Many commercial cultivars.

Population Dynamics and Dispersal:

Spreads by seed and rhizomes. Often forms clumps by vegetative spread.
Most local spread is by vegetative growth and transport of rhizomes rather than seedlings.

Origin and History:

South Africa

Distribution:

NSW, TAS, VIC, WA.
Naturalised at Porongorup, Albany and Denmark.
Lord Howe Island.

Courtesy Australia's Virtual Herbarium.

Habitats:

Prefer full sun to half shade situations.

Climate:

Prefers higher rainfall areas.

Soil:

Granitic soils to sands. Tolerate a wide variety of soils.

Plant Associations:

Significance:

Beneficial:

Ornamental.
Used as a herbal veterinary medicine in South Africa “The root is
boiled for ten minutes, cooled, strained and given to sheep and goats (200 mL
in the morning) to treat diarrhoea” (Dold and Cocks, 2001).

Detrimental:

Weed of roadsides, railways, old settlements, granite outcrops and urban bushland.

Toxicity:

Not recorded as toxic.
The sticky acrid sap in the leaves of Agapanthus praecox ssp. orientalis can cause severe ulceration of the mouth (Francis and Southcott, 1967).

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Avoid dumping garden rubbish on sites where establishment may occur.
Glyphosate is not very effective on this plant.

Thresholds:

Rarely invades agricultural situations.

Eradication strategies:

Cultivation, mowing and grazing provide control. Manually remove tops and root system and burn or bury more than 1 m deep.
Spray with 100 mL Garlon® in 10 L diesel when actively growing or wipe leaves with Tordon® or Vigilant® Gel herbicide. Glyphosate is not very effective on this plant.
Avoid dumping garden refuse on sites where establishment may occur.
It rarely invades agricultural land.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Easter lily (Amaryllis belladonna), Daffodil and Jonquil (Narcissus spp.) used to be in the same family.

Plants of similar appearance:

Kangaroo Paws (Anigozanthos species) have leaves which are dark green, 2-25 mm wide, and often mottled with unsightly dark brown to black markings. Its inflorescence is branched and has fan-shaped flowers which are densely woolly.
Easter Lily (Amaryllis belladonna) has white to pink flowers in autumn and narrower channelled leaves in a less dense basal tuft.
Chincherinchee (Ornithogalum thyrsoides) also has fewer basal leaves arising from a bulb and heads of white flowers whose petals have a dark blotch.

References:

Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).

Dold A. P. and Cocks M.L. (2001). South African Journal of Science 97, 375-379. September/October 2001

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).

Francis DF and Southcott RV (1967) Plants Harmful to Man in Australia (Miscellaneous Bulletin No. 1, Botanic Garden Adelaide). Adelaide: WL Hawes, Government Printer

Hussey, B.M.J., Keighery, G.J., Cousens, R.D., Dodd, J. and Lloyd, S.G. (1997). Western Weeds. A guide to the weeds of Western Australia. (Plant Protection Society of Western Australia, Perth, Western Australia). P18.

Lamp, C. and Collet, F. (1990). A Field Guide to Weeds in Australia. (Inkata Press, Melbourne).

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #22.1.

Moore, J.H. and Wheeler, J.R. (2008). Southern Weeds and their Control. (Second Edition). Department of Agriculture and Food Western Australia. P38-39. Photos.

Wheeler, Judy, Marchant, Neville and Lewington, Margaret. (2002). Flora of the South West: Bunbury - Augusta - Denmark. (Western Australian Herbarium, Bentley, Western Australia). P235. Diagram.

Acknowledgments:

Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.