Twining Toadflax

Kickxia elatine (L.) Dumort ssp. crinita (Mabille) Greuter

Synonyms - Kickxia sieberi, Linaria elatine

Family: - Scrophulariaceae.

Names:

Kickxia commemorates Jean Kickx, a Belgian Professor.

Elatine

Twining Toadflax

Other Names:

Sharp-leaved Fluellen

Pointed Toadflax

Twining Toadflax (Kickxia elatine ssp. crinita)

Woolly Toadflax (Kickxia elatine ssp. elatine)

Summary:

A hairy, running annual to perennial vine with small purple and yellow, straight-spurred flowers from November to May on long fine stalks from the axils of the arrow shaped, hairy leaves.

Description:

Cotyledons:

Two. Round to heart shaped, tip indented, hairy, stalk about the same length as the blade, stalk is hairy. Base of blade almost at right angles to the stalk. Surface dull, hairy. Stem below cotyledons hairy.

First leaves:

Oval, opposite. Tip round. Edges slightly toothed. Base squarish to round. Surface shiny. Petiole short with long hairs.

Leaves:

Alternate, lower ones may be opposite.

Petiole - Short.

Blade - Greyish green, egg shaped to broadly egg shaped, usually arrow shaped at the base or with a few coarse teeth, 4-30 mm long by 3-20 mm wide. Veins in a feather like arrangement. Upper leaves are smaller. Densely hairy.

Stems:

Greyish, low lying, sprawling with long simple and glandular hairs.

Flower head:

Single flowers on thread like stalks(pedicels), 7-12 mm long in axils of leaves. Pedicel spreading and hairy below the flower and hairy or hairless on the rest depending on the sub species.

Flowers:

Purple and yellow with a long spur.

Ovary - Stigma tiny.

Sepals - 5, joined at the base, narrowly egg shaped, similar lengths, 3-4.5 mm long by 1-2 mm wide, acute tipped, slightly bigger when in fruit.

Petals - 7-12 mm long, tubular with a spur, 2 lipped. Upper lip 2 lobed, violet. Lower lip, yellow, 3 lobed with projecting palate closing the throat. Spur is narrowly conical, acute tipped, straight or only slightly curved.

Stamens - 4, in two set of 2, inside the petal tube.

Anthers -

Fruit:

Globular, slightly flattened, 4 mm wide, 2 celled capsule, slightly shorter than the calyx. Releases many seeds by 2 lids that fall off when ripe.

Seeds:

Red brown, dull, elliptical, 1 mm long with a honeycomb pattern on the surface or pitted. Tip round and rough. Edges curved and rough. Base round and rough. Surface round dimpled and lumpy.

Roots:

Key Characters:

Corolla 2 lipped, 8-10 mm long, tube with a straight spur at the base and the throat closed. Calyx 5 lobed. Sepals narrowly ovate, 3-4 mm long by 1-2 mm wide. At least some leaves hastate or sagittate at the base with smooth edges and pinnately veined. 4 stamens. Villous. Seeds pitted.

Biology:

Life cycle:

Annual or perennial. Germinates in late winter to summer forming a mat of low lying stems. Flowers in summer to autumn and dies in early winter. Stems and stubble interfere with cultural operations.

Physiology:

Reproduction:

By seeds.

Flowering times:

December to May in SA.

November to April in Perth.

Seed Biology and Germination:

Seed remains dormant while in the dark and this dormancy is broken by exposure to light. However, in the field most germination occurs in dark conditions such as in stubble retention systems.

About 1-5% of the seed bank is expected to germinate each year and the viable seed bank falls by about 40% per year.

It normally builds up considerable soil seed banks.

Vegetative Propagules:

None.

Hybrids:

Twining Toadflax (K. elatine ssp. crinita) has pedicels that are hairy all over and is in SA, NSW, VIC and WA.

Woolly Toadflax (K. elatine ssp. elatine) has pedicels that are hairless except just below the flower and is in SA and WA.

Allelopathy:

Population Dynamics and Dispersal:

Spread by seed.

Habitats:

Climate:

Temperate. Mediterranean.

Soil:

Tends to prefer neutral to alkaline clayey soils.

Plant Associations:

Summer Grass (Digitaria sanguinalis), Canadian fleabane (Conyza canadensis) and wind-dispersed weeds,

Origin and History:

Europe, North Africa and south western Asia.

Distribution:

NSW, QLD, SA, VIC, WA.

Significance:

Beneficial:

Related species have compounds used for diabetes treatment in Indian herbal medicine.

Detrimental:

Weed of roadsides, disturbed areas, crops, pastures, fallow, stubbles gardens, plantations and minimum tillage.

Stems tangle in cultivating implements in autumn.

Toxicity:

Not recorded as toxic. Contains iridoid glucosides which are suspected to make caterpillars feeding on Kickxia less prone to predators.

Legislation:

None.

Management and Control:

Tends to build up in minimum tillage situations. Tillage (even superficial workings) tend to reduce the density of Toad Flax.

Thresholds:

Eradication strategies:

Diuron based products are expected to provide good control. Fluroxypyr (Starane) and quinmerac are used for control overseas.

Herbicide resistance:

Some populations tolerant to herbicides have developed in Europe after 20 years of herbicide use.

Biological Control:

Related plants:

Round-leaved Toadflax (Kickxia spuria) is a garden weed with rounded leaves and the spur on the flower is curved.

Twining Toadflax (Kickxia elatine ssp. crinita)

Woolly Toadflax (Kickxia elatine ssp. elatine) is a garden weed.

Kickxia commutata

Plants of similar appearance:

Bartsia (Parentucellia viscosa) is similar when young but has yellow flowers and an upright, winter growth habit.

Mulleins (Verbascum spp.) are larger with yellow flowers.

White Bartsia (Bellardia trixago) is similar when young but has white flowers and an upright, winter growth habit.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P764.

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). P214. Photo.

Lazarides, M. and Hince, B. (1993). CSIRO handbook of economic plants of Australia. (CSIRO, Melbourne). #708.2, 708.3.

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). #547.2, 547.3

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P587.

Moerkerk, M.R. and Barnett, A.G. (1998). More Crop Weeds. R.G. and F.J. Richardson, Melbourne. P117. Diagrams. Photos.

Zanin, G. Otto, S. Riello, L. and Borin, M. (1977) Ecological interpretation of weed flora dynamics under different tillage systems. Ecosystems and Environment. 66: 3, p177-188

Acknowledgments:

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