Hakea

Hakea species

Synonyms -

Family: Proteaceae

Names:

Protea is from the sea god, Proteus, who could take on many forms and alludes to the great range of leaf shapes found in the Proteaceae family.

Other Names:

Summary:

Evergreen, perennial shrubs or small trees with alternate, leathery, toothed or deeply divided leaves and many, paired flowers in a head.

Description:

Cotyledons:

Two.

First leaves:

Leaves:

Alternate, often prickly toothed or divided.
Stipules - None.
Petiole -
Blade - leathery, upper and lower surfaces similar.

Stems:

Forked hairs.

Flower head:

Flowers in loose, short racemes or umbels which are usually axillary.
Flowers on short stalks, in pairs with a common bract underneath.

Flowers:

Hermaphrodite
Ovary - Superior, smooth and hairless, 1 celled with 2 ovules.
Style - Simple, terminal
Stigma - Small
Calyx - Claw usually curved. Limb globular or egg shaped.
Sepals - 4, with a concavity
Stamens - 4, fertile, opposite sepals and inserted into them.
Anthers - almost stalkless in the concavity of a sepal.
Nectary a broad gland next to the ovary.

Fruit:

Fruit releases seed when ripe.
Seed follicle thick and woody, 2 valved, persistent.
No septum between seeds in follicle.

Seeds:

2, flat, with a membranous, usually broad, wing.
Body often with warts on the outer surface.

Roots:

Key Characters:

Leaves alternate. Often toothed or deeply divided. Upper and lower surfaces usually similar.
No stipules.
Flowers in usually in short racemes, appearing clustered and are in the leaf axil.
Flowers grouped, usually with each pair of flowers subtended by a common bract.
Involucre bracts usually conspicuous, not broadly based, persistent.
Calyx of 4 sepals.
Sepal limb not becoming spiralled.
4 stamens, opposite to and inserted into the perianth segments
Anther borne in a concavity, near the end of a sepal.
Superior ovary.
Fruit a 2 seeded, woody, very thick walled follicle, often persistent.
Fruit releases seed when ripe.
Follicle with no septum.
Seed flat, winged.
From Nancy Burbidge, and B.L. Rye.

Biology:

Life cycle:

Perennial

Physiology:

Reproduction:

By seed.

Flowering times:

Seed Biology and Germination:

Vegetative Propagules:

Some species sucker from the roots (eg H. ivoryi).

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed. Some species sucker from the roots.

Origin and History:

Distribution:

ACT, NSW, NT, QLD, SA, TAS, VIC, WA.

Habitats:

Climate:

Temperate.

Soil:

Plant Associations:

Significance:

Beneficial:

Ornamental, amenity and rehabilitation area plantings. Some are salt tolerant.
Craft wood with some interesting patterns.
Some species are honey plants. Some used for gum extraction.
Silky Hakea (Hakea sericea) used for sweeping chimneys.

Detrimental:

Little forage value.
Some species are environmental weeds e.g. Hakea costata, Hakea francisiana, and Hakea pycnoneura.

Toxicity:

Some species may contain toxic levels hydrocyanic (prussic) acid.
Cyanogenetic.

Symptoms:

HCN poisoning.
Sudden death, profuse scouring and gastro-enteritis.

Treatment:

Remove stock from infested areas or provide alternative feed.
Don't expose hungry sheep to infestations.
Treat as for cyanide poisoning.

Legislation:

The Wildlife Conservation Act prohibits removal of native plants from the wild in their native range on government land.

Management and Control:

Physical removal is usually effective. Suckering species may require spraying.

Thresholds:

Eradication strategies:

Bulldoze the area, then burn to encourage seeds to germinate. Cultivate or spray to control seedlings.

Herbicide resistance:

None reported

Biological Control:

Unlikely because there are many closely related native species.

Related plants:

Candle Hakea (Hakea ruscifolia)
Corkbark Tree (Hakea ivoryi)
Gnarled Corkbark (Hakea fraseri)
Hedgehog Hakea (Hakea erinacea)
Honey Bush (Hakea lissocarpha)
Hooked Needlewood (Hakea tephrosperma)
Horned Leaf Hakea (Hakea ceratophylla)
Myrtle Hakea (Hakea myrtoides)
Needlewood (Hakea leucoptera)
Prickly Hakea (Hakea amplexicaulis)
Ramshorn (Hakea cyclocarpa)
Ribbed Hakea (Hakea costata) has escaped from plantings.
Sea Urchin Hakea (Hakea petiolaris)
Shell-leaved Hakea (Hakea conchifolia)
Silky Hakea (Hakea sericea) - Weedy. Introduced to make chimney sweeps and native to South Africa, Spain and New Zealand.
Straggly Corkbark (Hakea eyreana)
Willow-leaved Hakea (Hakea salicifolia) - Weedy
Hakea drupacea - Weedy. Native of WA, naturalised in Vic.
Hakea eriantha - Weedy.
Hakea elliptica - Weedy/
Hakea francisiana has escaped from plantings.
Hakea laurina - Weedy.
Hakea pycnoneura has escaped from plantings.

Plants of similar appearance:

Banksia spp.
Dryandra spp
Grevillea spp.
Hakea spp.
Isopogon spp
Protea spp.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne).

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia).

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

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P146. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P216-218. Photos.

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

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P21.

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). #475.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P335-345. Diagrams.

Parsons, W.T. and Cuthbertson, E.G. (1992) Noxious weeds of Australia. (Inkata Press, Melbourne).

Acknowledgments:

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