Montpellier Broom

Genista monspessulana (L.) L. Johnson

Synonyms - Genista canariensis, Teline monspessulana, Cytisus canariensis, Cytisus monspessulanus.

Family: - Fabaceae.

Names:

Genista is the Latin name for this group of plants.

Monspessulana is Latin for Montpellier in France where the plant originated.

Cape Broom refers to Cape Verde near the Canary Islands because it was thought that this plant was Canary Broom.

Other names:

Broom

Canary Broom

Common Broom

French Broom (USA)

Montpellier Broom

Soft Broom (New Zealand)

Spanish Broom.

Summary:

An erect to slightly drooping, evergreen, perennial shrub, to 3 m tall, with trifoliate leaves and bright yellow pea type flowers in spring.

Description:

Cotyledons:

Two.

Leaves:

Alternate.

Stipules - small, egg shaped to triangular. Free from petiole.

Petiole - short, 2-4 mm long.

Blade - 3 finger like leaflets. The leaflets are lance shaped to wedge shaped, fleshy, smooth edges with a rounded tip or a small point and on short stalks. Hairy when young especially on conspicuous midrib underneath, less hairy on top. Green on top, greyish underneath. Middle leaflet 5-40 mm long, side leaflets shorter.

Stems:

Erect, woody, angular, striped, grooved, up to 3000 mm. Crimped hairs. Longer spreading hairs also on young flowering shoots. Becomes hairless with age. Usually has a main stem with many branches. Stems coppice if damaged.

Flower head:

Racemose clusters, of 3-9 flowers, at the ends of short branches with a few single flowers in leaf axils at the base of lateral branches.

Flowers:

Pea type and bright yellow. 10-12 mm long. On short stalk.

Bracts - narrow, papery attached to base of tube. Shorter than the tube

Ovary - Style is short and incurved.

Calyx - tubular, 5-6 mm long. Upper lip of 2 pointed lobes as long as the tube. Lower lip with 3 short lobes tapering to a fine point. Hairy.

Corolla - bright yellow. Standard petal, 10-12 mm long. Keel hairy towards the top.

Stamens - united by filaments in a tube around the ovary.

Anthers -

Fruit:

Pod brown or black, slightly curved, 4-8 seeded, flattened, 15-25 mm long by 5 mm wide, with silky hairs. Seeds explosively released. Coils after seed is released.

Seeds:

Dark brown to black, smooth, shiny, rounded, flattened, 2mm diameter.

Roots:

Branched taproot and many shallow laterals.

Key Characters:

Biology:

Life cycle:

Perennial. Seeds germinate in autumn and spring and grow slowly to flower when around 2 years old. Flowers in late winter to spring and may flower again at the end of summer. Seed pods burst on hot days catapulting seeds several metres from the parent plant. Evergreen plant with new growth formed in winter and spring.

Physiology:

Drought tolerant once established.

Reproduction:

By seed.

Flowering times:

Summer in western NSW.

Seed Biology and Germination:

Seed may remain in the soil for many years.

Seed dormancy is broken by fire.

Vegetative Propagules:

None.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Seeds explosively released scattering them several metres from the parent and accounting for most of the local spread.

Initially the major spread was from intentional planting. Now most spread is due to road making machinery moving the seed to new areas and in water flows. Some spread may be due to birds. Some spread is in contaminated produce and mud on animals and machinery.

It produces large quantities of seed.

Large numbers of seedlings emerge when vegetation is removed.

Origin and History:

Mediterranean, Europe, Azores.

Probably introduced to Australia as an ornamental hedge plant before 1850.

Distribution:

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

Habitats:

Climate:

Humid and sub-humid Mediterranean climates.

Soil:

Plant Associations:

Significance:

Beneficial:

Fermented flower buds are smoked and Mexican Indians use extracts as hallucinogens.

Ornamental used as a hedge plant and windbreak.

Fodder. Young plants are palatable.

Detrimental:

Weed of roadsides, railways, disturbed areas, watercourses and poorer pastures with and annual rainfall of more than 500 mm.

Forms dense thickets which excludes more desirable species and harbours vermin such as rabbits.

Forms an inflammable understorey on the edges of forests.

Toxicity:

Toxic if consumed in sufficient quantity. Sheep eat young plants without apparent problems if it is only a moderate portion of their diet. No cases of poisoning have been reported in Australia.

Symptoms:

Nausea, convulsions, respiratory failure then death.

Treatment:

Remove stock from infestations.

Legislation:

Noxious weed of VIC, SA and TAS.

Management and Control:

Grazing normally provides control.

Thresholds:

Forms dense thickets if left uncontrolled in suitable areas.

Eradication strategies:

Mechanically remove isolated plants and roots.

Seed dormancy is broken by fire and dense stands often develop after areas have been burnt. In denser infestations, slash, burn, then cultivate to kill emerging seedlings and sow perennial pastures to reduce reinfestation. Triclopyr plus picloram applied in spring provides good control. Repeat treatments are required for seedlings and regrowth from larger plants. Glyphosate is also used but high rates and repeated applications are required.

Herbicide resistance:

Biological Control:

Related plants:

Flax leaved Broom (Genista linifolia) has no petiole and narrower, linear to oblong leaflets that are rolled on the edges.

Madeira Broom (Genista stenopetala) has a longer petiole at 6-15 mm long.

Plants of similar appearance:

Broom (Cytisus scoparius) has a longer and coiled style.

White Spanish Broom (Cytisus multiflorus) has white flowers flecked with purple, grey green thinner stems

Gorse (Ulex europaeus) has darker flowers and is spiny. Its leaves are spine like and only has trifoliate leaves on the seedling.

Spiny Broom (Calycotome spinosa) is spiny.

Spanish Broom (Spartium junceum) has larger (20-30 mm) fragrant flowers with one lobe on usually leafless stems.

References:

Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P166. Photo.

Burbidge, N.T. and Gray, M. (1970). Flora of the Australian Capital Territory. (Australian National University Press, Canberra). P224.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). p422. Photo.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P421-422.

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

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #580.3.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P478-480. Photos.

Acknowledgments:

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