Long-tubed Ixia

Ixia paniculata Delaroche

Synonyms - Ixia hybrids.

Family: Iridaceae

Names:

Long-tubed Ixia because the flower has a much longer tube than other Ixia species.

Other Names

Summary:

Long-tubed Ixia (Ixia paniculata) is a tufted herb with long, narrow leaves arising annually from a corm. The flower spike is usually up to 50 cm high with a cluster of several pink to orange, tubular flowers. The flowers have 6 spreading petals with rounded petal lobes which are 1.5 to 2.5 cm long, 3 stamens and a 3-branched style. Originally from South Africa, Long-tubed Ixia has become a minor weed of roadsides particularly near old settlements and can be found invading woodlands. It flowers from spring to early summer.

Description:

Cotyledons:

One.

First leaves:

Leaves:

Prominent veins.
Blade - Narrowly elliptical, 300-400 mm by 4-8 mm.
Ligule - None.
Auricles - None.

Stems:

Slender and wiry. Erect usually with 1 or more almost erect branches.
Flower stem - 300-600 mm tall.

Flower head:

4-12 flowered, fairly loose spike,
Membranous floral bracts that are colourless at the base, brown near the tip and attached at the base of the ovary.

Flowers:

Orange-pink on the outside and cream to yellow underneath with a long narrow tube 6 radiating petals. Sessile.
Perianth - 60-70 mm long narrow tube with 6 spreading lobes. Outer 3, narrowly egg shaped, 20-25 mm long x about 6 mm wide. The inner three are slightly narrower.
Style - Thread like. Branches 2 mm long, spoon shaped, curved and folded lengthwise.

Stamens - Attached to the perianth tube. Filaments are free.
Anthers - Purple. 6 mm long. Erect.

Fruit:

Capsule but not seen in Australia.

Seeds:

Brown. Many.

Roots:

Small, 10-20 mm diameter, globular corms with fine roots and smaller cormels.

Key Characters:

Inflorescence unbranched and spike like with 4-12 flowers.
Flowers sessile.
Perianth tube 60-70 mm long.
Inferior ovary.
Style branches undivided.
3 stamens symmetrically arranged around the style.
2 membranous floral bracts.
Adapted from Gillian Perry, Flora of the Perth Region.

Biology:

Life cycle:

Annual leaves and stem with a perennial corm or corms.

Physiology:

Reproduction:

By corms.

Flowering times:

September to November in Perth region.
Spring in WA.

Seed Biology and Germination:

Doesn't produce seed in Australia.

Vegetative Propagules:

Corms.

Hybrids:

Population Dynamics and Dispersal:

Spread by movement of corms in water flows and soil.

Origin and History:

From South Africa.

Distribution:

SA, VIC, WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate.

Soil:

Light acid sands.

Plant Associations:

Significance:

Beneficial:

Ornamental

Detrimental:

Weed of roads, railways, old settlements and other disturbed areas.
It may form colonies that displace other plants.

Toxicity:

Not recorded as toxic.

Legislation:

None.

Management and Control:

Avoid moving soil from infested areas.
When applying foliar herbicides, use a wetting agent, especially on young plants as they are hard to wet.
2,2-DPA at 5 kg/ha plus 0.25% wetting agent applied before flowering provides good control in bushland.

Eradication strategies:

These plants are very difficult to control by hand weeding because they produce many small cormels under the main corm and the top tends to break off leaving the corm in the soil. Spray with 100 mL glyphosate(450g/L) or 100 g 2,2-DPA(740g/kg) in 10 L of water before flowering. The area will require spraying again next season to control the tiny seedlings emerging from cormels. Individual plants can be wiped with a mix of 1 part glyphosate in 2 parts water.
Grazing and mowing provide control.
Replant native shrub species if necessary. Avoid earth works that carry new cormels into the area. Start control at the top of the catchment to prevent water-transported cormels reinfesting treated areas.

Herbicide resistance:

None reported.

Biological Control:

Related plants:

Green Ixia (Ixia viridiflora)
Long-tubed Ixia (Ixia paniculata)
Variable Ixia (Ixia polystachya) has white flowers with a blue-green centre.
Yellow Ixia (Ixia maculata) has yellow flowers with a purple-brown to red centre.
Ixia cf. conferta
Ixia flexuosa
Ixia longituba
There are many cultivated hybrids.

Plants of similar appearance:

Cape Tulip has orange-pink flowers.
Daffodils and Jonquils have white to yellow flowers with 6 stamens rather than 3.
Freesia has larger flowers with a distinctive bend in the stem below the first flower.
Gladiolus has leafy floral bracts and the flowers tend to be on one side of the stem.
Iris has 2 or more flowers in each spathe and much broader leaves.
Kangaroo Paws has broader leaves and red, black or green flowers shaped like kangaroo paws.
Montbretia (Crocosmia X crocosmiiflora) has stolons.
Patersonia has single 3 petal, purple flowers.
Snowflake has white flowers with 6 stamens rather than 3.
Sparaxis has two tiny lobes on the style branches.
Watsonias and African Cornflag are much larger.

References:

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

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

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). P34. Photo.

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). 539.4.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P797.

Acknowledgments:

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