Senecio is from the Latin senex meaning old man and refers to the beard like pappus on the seed.
glastifolius
Holly-leaved Senecio refers to the toothed shape of the leaves, like Holly, and it membership of the Senecio genus.
Other names:
Large Senecio.
Waterdissel.
Pink Ragwort.
Summary:
A many branched, stout, erect, perennial shrub, usually about 1 metre tall with toothed, oblong leaves and clusters of purple to pink, daisy like flowers with yellow centres at the ends of the branches in spring.
Originating from South Africa it is a weed of woodland areas near Albany and flowers in spring.
Description:
Cotyledons:
Two.
Leaves:
Petiole -. Clasps the stem.
Winged and on lower leaves and stem clasping with the wings continuing down the stem.
Blade - Elliptic to egg shaped and clasp the stem. The lower leaves are 100 - 150 mm long by 30 - 50 mm wide and become smaller up the stem to around 30 -50 mm long near the top. The edges are serrated and often coarsely toothed near the base. Upper leaves are more finely serrated.
Variable, narrowly egg shaped and may have coarsely toothed margins, up to 150 mm long by 7-25 mm wide, leathery, dark green and almost hairless on the upper surface and white with woolly hairs on the underside. Tapering into the petiole.
Stem leaves - Narrower and without a petiole.
Stems:
1000-1500 mm tall and occasionally to 2000 mm. They are soft when young and become woody with age and up to 80 mm wide at the base. The stems branch in older plants. the branches are widely spaced and carry terminal clusters of flowers
Grey-green, erect, up to 3000 mm tall and usually about 1000 mm tall, many branched, stout, soft and sappy when young and becoming woody with age, lengthwise striped, ribbed and carry cobwebby, fine, woolly hairs. Wings on the lower stems.
Flower head:
The clusters of flowers range from 2-3 per plant to several hundred that form a loose corymb with supplementary bracts that are 3-5.5 mm long.
Flower base(involucre) bell shaped.
Flowers:
Composite (Daisy like) with 12-22 pink to purple ligulate ('petal') florets round the margin of the 'flower'.
Bracts - 19-23 inner bracts that are 6 - 9 mm long and narrow.
Ovary - Flat receptacle with a honey comb like surface with the edges forming tiny scales?
Florets - Ray florets, 12-22 with 12-25 mm long, purple to almost white petals(ligules). Disk florets, yellow, tubular.
'Petals' - 12-22, Purple to almost white and 12-25 mm long.
Stamens -
Anthers -
Fruit:
Achenes are about 2.5 mm long by 0.6 mm diameter, round in cross section and hairy or hairless.
Pappus is 7-9 mm long.
Seeds:
2 mm long by 0.6 mm wide. 0.6-0.8 mg.
Roots:
Relatively shallow taproot with several laterals.
Key Characters:
Erect perennials or sometimes annual.
Stems often woody towards the base.
Purple to almost white daisy like flowers, 25-50 mm diameter
Toothed leaves.
Biology:
Life cycle:
Perennial or sometimes annual. Seeds germinate from late summer (February) through to August. Maximum seedling establishment occurs on bare areas. Early growth is rapid and stems form from July and rapidly elongate. The first year plants are usually single stemmed. They flower in spring and seeds ripen 2-3 weeks after flowering. A smaller flowering may also occur in autumn. Branches arise from the axils of the flowers of the previous season. The age of the plant can be estimated by counting the layers of flowers stalks. Few plants appear to be more than 4 years old. They become top heavy with age and tend to break off at ground level. The plant may re sprout where it has broken. Fallen stems may continue to grow and occasionally form roots where they contact the ground. Plants that appear to die after flower usually re shoot in the following autumn.
Physiology:
Grow rapidly and may reach a height of 1500 mm tall by 500 mm wide in 2 years.
Reproduction:
By seed and a perennial crown.
Flowering times:
Spring in WA. Mainly October in NZ with some in January/February.
Seed Biology and Germination:
Germination starts about a week after the seed is moistened and is staggered over at least 70 days. 50-80% of field collected seed germinated in NZ populations. It probably needs relatively high temperatures around 200C for maximum germination. It probably doesn't have a persistent seed bank.
Seed production is around seeds per plant.
Probably require light, germination levels probably drop at about 25% full sun.
Little dormancy.
Vegetative Propagules:
Perennial crown. Occasional growth from broken stems in contact with the ground.
Hybrids:
Allelopathy:
Population Dynamics and Dispersal:
Spread by seed that is blown in the wind, carried by water, animals and on vehicles and machinery or in mud. Most seed will probably fall close to the parent plant because the pappus readily breaks from the seed.
Some has been spread as a contaminant in soil used for road making and in agricultural produce.
It quickly invades areas that have been cleared or burnt and is often in close proximity to gardens where it was originally planted.
Origin and History:
South Africa. Confined to a narrow coastal strip.
Distribution:
NSW, WA.
In WA it is around Albany from Elleker to Lower King with the main infestation near Mt Adelaide and Mt Clarence. First collected in 1986 and was well established at that time.
NZ. First found in New Zealand in 1963 near Gibsorne in the southern North Island and is now rapidly spreading in coastal areas. It is also present on the South Island.
Courtesy Australia's Virtual Herbarium
Habitats:
Climate:
Temperate. In latitudes from 30-400S with winter or all-year rainfall of .
Tolerates wind and grows best in areas or full sunlight to light shade.
Most abundant in areas with an annual rainfall is 500 - 1600 mm.
Soil:
Most abundant in coastal areas on the light to medium soils and those derived from granite. Stream banks, marshy land. Unlikely to tolerate waterlogged areas. It has some degree of salt tolerance
Plant Associations:
Banksia woodlands, scrubland, disturbed areas and granite outcrops. More frequent on sparsely vegetated sites.
In Australia, it is relatively rare and the major infestations are around Albany in WA. It has the potential to spread over large areas of land in the next few decades if some form of control is not imposed.
Beneficial:
Ornamental.
Palatable to sheep.
Detrimental:
Weed of new plantations, unimproved land, roadsides, denuded areas, burn sites, poorly grazed, pastures, urban bushland and disturbed areas.
Grows vigorously on burnt areas and may reduce the establishment of native species after fire.
It greatest environmental impact is likely to be in periodically waterlogged scrubland.
Toxicity:
Not recorded as toxic but other members of this family are toxic.
Legislation:
Banned in parts of New Zealand.
Management and Control:
Cultivate then plant competitive pastures. Slash as necessary to allow pasture to establish.
Graze heavily with goats or sheep in areas that can't be cultivated monitor stock regularly for toxic effects.
In bushland situations, hand pulling over several seasons in winter is effective but needs to be repeated in late spring to capture missed individuals. Wiping the stems with glyphosate is also effective if done before flowering. In heavy infestations misting with Lontrel is being investigated.
Plants cut just above ground level did not sprout in a New Zealand trial (R. Halsey).
Hand pulling on typical infestations takes about 2-4 man days per hectare per year. Heavy infestations require 6-10 man days per hectare per year. For budgeting purposes, about 20 man days per hectare, spread over 3-4 years is required to achieve high levels of control by manual removal. In NZ, hand pulling gave control levels of 98% in open terrain, 50% -90% in undulating sand dunes. In WA, hand pulling in bushland controlled 75-85% of plants.
Thresholds:
Eradication strategies:
Prevent seed set.
Hand pulling the plants or cutting at ground level in spring before flowering for a few years should provide control. Flowering plants need to be bagged and burnt as seed will mature on nutrient reserves within the stems.
Lontrel®750 at 200 g/ha applied before stem elongation in late spring provides reasonably selective control in coastal heath and bushland. For hand spraying use 4 g Lontrel®750 in 10 L water.
Small infestations can be treated with 100 mL Tordon®75-D in 10 L water which will control the plants and leave a soil residue for control of later emerging seedlings.
Cultivation and grazing provides reasonable control.
New infestations in bushland tend to establish after disturbance or fire.
Herbicide resistance:
None reported.
Biological Control:
Related plants:
Bushy Groundsel (Senecio cunninghamii)
Cape Ivy (Senecio angulatus)
Cape Ivy (Senecio mikanioides)
Common Groundsel. (Senecio vulgaris)
Commonwealth weed (Senecio bipinnatisectus)
Cotton Fireweed (Senecio quadridentatus)
Feathery Groundsel (Senecio anethifolius)
Fireweed (Senecio lautus) has yellow flowers and is a native.
Fireweed Groundsel (Senecio linearifolius)
Fleshy Groundsel (Senecio gregorii)
Hispid Fireweed (Senecio hispidulus)
Mountain Fireweed (Senecio gunnii)
Purple Groundsel (Senecio elegans) is an annual, smaller plant with lobed rather than toothed leaves and the bracts under the flower have a tiny dark tip.
Ragwort (Senecio jacobaea)
Slender Groundsel (Senecio glossanthus)
Squarrose Fireweed (Senecio squarrosus)
Tall Groundsel (Senecio runcinifolius)
Tall Yellowtop (Senecio magnificus)
Senecio daltonii
Senecio madagascariensis
Senecio megaglossus
Senecio tamoides
Plants of similar appearance:
Purple groundsel (Senecio elegans) is a very similar but is an annual, smaller plant with lobed rather than toothed leaves and the bracts under the flower have a tiny dark tip.
Nearly all our native Senecio species have yellow flowers except Senecio leucoglossus which has white to pale purple flowers.
References:
Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P182-183xxx.
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). P104
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). #919.6.
Moore, J.H. and Wheeler, J.R. (2002). Southern Weeds and their Control. Photos.
Williams, P.A., Ogle, Colin C., Timmins, Susan M, La Cock, Graham, and Reid, Virginia. (1998). Notes on the biology and ecology of Senecio glastifolius L. and its spread and impacts in New Zealand. Science and Research Unit, Department of Conservation.
Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.
