One-leaved Cape Tulip

Moraea flaccida Sweet

Synonyms - Homeria flaccida Sweet, Homeria collina, Homeria collina var. aurantiaca, Homeria Breyniana, Homeria ochroleuca Salisb.

Family: Iridaceae

Names:

Homeria means to join and refers to the united stamens.
Flaccida means limp referring to the drooping leaf when mature.
Ochroleuca means yellow flower.
One-leaved Cape Tulip refers to the single leaf, its origin from the Cape of Good Hope and Tulip because in its country of origin, South Africa, it is known as "Tulps".

Other Names:

Yellow flowered Cape Tulip refers to the yellow flowered varieties of both One-leaved and Two-Leaved Cape Tulip species.

Summary

One-leaved Cape Tulip is a herb with a single sprawling basal, dark green, strap like leaf to 700 mm long produced annually from a small corm. The branched flowering stem has short-lived pink to orange (or rarely yellow) flowers. The flowers each have 6 petals, 3-4 cm long, 3 stamens and a 3-branched style in which each branch has 2 short lobes or 2 short crests. It reproduces by seeds as well as corms.
Prior to flowering, Cape Tulip can be recognised by the browning-off of the leaf tips. It has annual tops with a perennial corm.
It is native to South Africa and has become a weed of pasture, roadsides and disturbed bushland. It flowers in late winter and spring.
It is toxic to stock and most deaths occur in hungry animals that have recently been introduced to the plant.
Cape Tulips were previously assigned to the genus Homeria.

Description

Cotyledons:

One.

First leaves:

Very fine. Growth from corms is stronger than that from seed. First leaf from the corm is folded.

Leaves:

Usually single, long and narrow up to 1000 mm long x 4-15 mm wide. Ribbed, mid vein prominent. Pointed tip. Hairless. Limp at maturity. Folded at the base and flat or turned up at the edges above. Closed sheath. The part of the leaf below ground level is a rich yellow colour. The outer surface is usually darker and shinier than the inner surface.
Stem leaves - 2-4, short and bract like. Clasp the stem.

Stems:

Flower stem: Single, erect and enveloped by the sheathing base of the leaf. Stiff. Cylindrical. Zig zag. Up to 700 mm. Branched near top or simple.

Flower head:

Branched. The base of each branch is enveloped by a spathe or modified leaf.

Flowers:

Salmon pink, orange or yellow. Yellow triangular patches, outlined in orange, in the throat. 30-50 mm diameter. Each flower on a short stalk in small clusters of 1-4 flowers at the end of branches. The base of the flower stalks are enveloped by a membranous spathe that becomes lacerated at the tip with age. Unpleasant, sickly sweet smell. Opens early in the morning and fade by late afternoon.
Ovary - Inferior, 3 celled. Style has 3 orange branches, 4-5 mm long that are notched at the tip and hairy on the outer edge.
Perianth - Funnel shaped forming a small cup. With 6 free segments ('petals'), 3 inner and 3 outer ones. Up to 50 mm wide by 25-60 mm long.
Stamens - 3, opposite the outer perianth segments, with 3 staminodes in between. Filaments (6-8 mm long) completely united to form a tube around the style.
Anthers - Anthers 8-9 mm long and erect. Linear. Pressed against the style branches.

Fruit:

Green turning brown on maturity. Cylindrical, 3 valved capsule 30-55 mm long, 6 mm wide with a 2 mm long beak. Opens at the top to release seed. 3 valved capsule containing up to 150 seeds. It projects from the spathe at maturity.

Seeds:

Brown. 2 mm long. Irregular shape, angled with slightly winged margins.

Roots:

Fine. Shallow. Fibrous. Sometimes has thick contractile roots. Bulb like corms formed. A contractile root may form under the corm to pull it deeper into the soil each year.

Corms:

Spherical to tear shaped, 8-20 mm diameter. Underground at base of plant. Surrounded by brown, spine tipped, latticed, fibrous material that falls away with age. The corm is yellow after removal of the covering. 1-3 corms are produced above the old corm annually. Up to 7000 corms per square metre have been recorded. Young corms tend to be near the surface and corms from older plants tend to be deeper and up to 100 mm deep.

Key Characters:

Salmon pink, orange or yellow flowers with 6 'petals'.
8-20 mm tear shaped corm(s) at the base of the plant.
Long usually single basal leaf.

Biology:

Life cycle:

Perennial corm and annual tops. It is 300-700 mm tall, with a winter growing annual leaf and flowers. Germinates autumn/winter from seeds and corms. (In Tasmania, it germinates in spring and grows through the summer) Seeds are short lived with few surviving more than a year. They germinate most readily on the surface and won't germinate if buried more than 50 mm deep. Most corms will germinate under moist, warm autumn conditions. A cold late break to a season results in many corms becoming dormant. One or two new corms start forming at the base of the stem early in the season and old corms are consumed during winter. Flowers appear when the corm is exhausted, usually in early spring. Seed is produced soon afterwards. Aerial growth dies in summer and usually breaks off. The corms go dormant over summer. Plants from seed take 2-3 years to build up the corm size and flower. Some plants form a fleshy root below the corm that dries in summer pulling the corms deeper into the soil. This results in young plants having corms nearer the surface and older plants having corms at about 100 mm deep. Corms have varying dormancy resulting in varying densities in different seasons. Over half may remain dormant for the whole growing season making control difficult. Control programs usually have to be continued for several years. It flowers from September to November.

Physiology:

Australian varieties tested were hexaploid (Morrison and Scott, 1995).
Somewhat tolerant of salt.

Reproduction:

Seed and Corms.

Flowering times:

September to November in WA.
Early to mid spring in SE Australia

Seed Biology and Germination:

Seed rarely survives in the soil for more than one year.
Seed can pass through the gut of stock and native animals without a significant loss of viability.

Vegetative Propagules:

Corms and cormels.
Corms may remain viable for a few in the soil. Up to 7000 corms per square metre of soil have been recorded.
Up to 60% of corms may remain dormant in the soil over the winter growing period. The degree of dormancy of the corm depends on the seasonal conditions in autumn. If substantial rainfall occurs in early autumn when the soil is warm then most corms will germinate. If soils are cooler when the first rains come then many corms will remain dormant for the year. Corm dormancy is usually less on burnt areas, possibly due to warmer soil temperatures or better penetration of rain.

Hybrids:

Ecology, Population Dynamics and Dispersal:

Mainly spread by seed in farm produce (especially hay and silage) or corms in soil adhering to machinery or animals. Seed is also spread by attachment to wool and in animal dung (especially cattle). Wind or water may spread capsules. Road making machinery spreads it along road verges.

Origin and History:

Native to the Cape region of Southern Africa. Introduced as an ornamental garden plant.

Distribution:

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

Courtesy Australia's Virtual Herbarium.

Habitats:

Prefers sunny locations.

Climate:

Temperate.

Soil:

Usually occurs on the heavier soil types, especially the red granite derived loams. It will grow on a wide range of soil types.

Plant Associations:

Pastures, roadsides and disturbed areas.

Significance:

Beneficial:

Introduced to Australia as an ornamental plant.

Detrimental:

Carrying capacity of pastures is reduced because it displaces other species and stock avoid eating it.
Weed of cereal crops, pastures and disturbed lands.

Toxicity:

Toxic to cattle, sheep, donkeys, goats, elephants and humans. It is only rarely toxic to horses. Green leaves are the most toxic followed by other green parts then dry material. Corms are also toxic. Toxic cardiac glycosides have been extracted from the plant.
Most losses occur in stock recently introduced to an infestation. Stock accustomed to grazing infested areas are rarely affected. After treatment with hormone herbicides (such as Spray Grazing using 2,4-D) animals may consume more Cape Tulip and suffer toxicity. Cattle are more susceptible than sheep or horses. Eating corms has caused human deaths. Cockatoos eat corms exposed by cultivation with no apparent effects.
They have a digitalis like action on the heart.
One kilogram of fresh green leaves fed to a cow can cause death within 24 hours.

Symptoms:

Symptoms include scouring, loss of appetite, a "tucked up" stance, and evidence of abdominal pain, stiffness of the hind legs, blindness, depression, weakness, dysentery and morbidity. Skin, gums and inside the eyelids are pale. Death may occur from a few hours to 3 days of ingestion of the plant.

Treatment:

Treatment is by charcoal or kaolin dosing. Potassium salts may alleviate digitalis type symptoms.
Hungry and unaccustomed stock should be denied access to Cape Tulip.

Legislation:

Noxious weed of WA, SA, NSW, VIC and TAS.

Management and Control:

Apply 1 L/ha 2,4-D amine each year in late winter before flowering.

Thresholds:

Eradication strategies:

Reduce seed viability by burying to more than 50 mm. Increase corm germination by increasing the effectiveness of early rains by clearing trash with burning or cultivation in late summer and controlling summer weeds. Germinated corms can be controlled with herbicides. Cultivation to 150 mm only provides good control if done after the old corm is exhausted and before the new corms form. This usually occurs over a fortnight period in June or July but varies considerably between seasons and may be as late as September. Dig up plants to determine the stage of the corms. A follow up cultivation is also needed. A 4 year program is required. Treatment with herbicides can be effective but timing and conditions are often critical to achieving good results. Hormone herbicides (such as 2,4-D ester) are most effective when applied just before or at flowering. Sulfonylurea herbicides (such as Glean® and Ally®) appear to work over a wider range of application times. Glyphosate, amitrole, 2,2-DPA and imazethapyr also have provided good control. Glyphosate may be applied with a wick applicator in spring to reduce damage to pasture species. In non agricultural conditions a mixture of amitrole+atrazine+2,4-D is effective. This leaves the soil bare which encourages germination in following seasons.
Control by manual removal is difficult due to many dormant corms in the soil and the top often breaks off leaving the corm in the soil. Use a fork or trowel to loosen the soil so the corm may be removed. Burn the corms and seeding tops or drench with diesel.
Slashing, mowing, grazing and cultivation are usually ineffective.
For small infestations
Hand spray until just wet in June to early September each year with one of the following mixtures: 0.2 g of chlorsulfuron(750g/kg) or metsulfuron(600g/kg) or 100 mL glyphosate(450g/L) in 10 L water plus 25 mL Pulse®.
Use 50 mL amitrole(250g/L) plus 25 g simazine(900g/kg) plus 50 mL 2,4-D amine(500g/L) plus 25 mL Pulse® in 10 L water for areas such as firebreaks. In sensitive areas in spring, use a blanket wiper or sponge glove using 1 L of glyphosate or 2 g of chlorsulfuron(750g/kg) or metsulfuron(600g/kg) in 2 L of water. 1-2 L/ha of paraquat in spring is also effective.
In clover based pastures, an annual 'spray graze' with 750 mL/ha 2,4-D amine(500g/L) is cheap and effective. Spinnaker® is useful in other legume pastures.
Control normally takes several years and follow up is essential. Cultivation to expose the corms a few weeks after spraying may improve control.

Herbicide resistance:

None reported.

Biological Control:

CSIRO are investigating insects and rusts.

Related plants:

Moraea fugax Is not common in WA.
Moraea lewisiae is uncommon and occurs around Perth on clayey soils.
Moraea miniata (Two-leafed Cape Tulip) has more than one leaf, does not produce viable seeds, is usually smaller, has cormels below the corm and in leaf axils and has a scaly tunic around the corm.
Moraea ochroleuca has flowers with an unpleasant odour and often seen after fire.
Moraea setifolia occurs in Wandoo and York Gum woodlands of the WA wheat belt.
Moraea vegeta is rare and found at Maddington and Casuarina woodland in the wheat belt.

Plants of similar appearance:

Thread Iris (Gynandriris setifolia).

References:

Black, J.M. (1978). Flora of South Australia. (Government Printer, Adelaide, South Australia) P373. Diagram.

Cunningham, G.M., Mulham, W.E., Milthorpe, P.L. and Leigh, J.H. (1992). Plants of Western New South Wales. (Inkata Press, Melbourne). P192.

Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney). P375.

Gardner, G.A. and Bennetts, H.W. (1956). The toxic plants of Western Australia. (West Australian Newspapers Ltd, Perth). P18-20.

Gilbey, D. (1989). Identification of weeds in cereal and legume crops. Bulletin 4107. (Western Australian Department of Agriculture , Perth). P14-5. Photos.

Hyde-Wyatt, B.H. and Morris, D.I. (1980) The Noxious and Secondary Weeds of Tasmania. (Tasmanian Department of Agriculture, Hobart, Tasmania). P34-35. Diagram.

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

Marchant, N.G., Wheeler, J.R., Rye, B.L., Bennett, E.M., Lander, N.S. and Macfarlane, T.D. (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P796.

McBarron, E.J. (1983). Poisonous plants. (Inkata Press, Melbourne). P55. Diagram.

Meadly, G.R.W. (1965). Weeds of Western Australia. (Department of Agriculture - Western Australia). P53-8. Photos. Diagrams.

Moore, J.H. and Wheeler, J.R. (2002). Southern Weeds and their Control. Photos.

Morrison, S.M. and Scott, J.K. (1995) Chromosome numbers of Cape tulips (Homeria species) in South Australia and Western Australia. Plant Protection Quarterly, 10(3):96-98.

Muyt, A. (2001). Bush Invaders of South-East Australia: a guide to the identification and control of environmental weeds found in South East Australia. (R.G and F.J. Richardson, Australia). P94-96. Photos.

Parsons, W.T. and Cuthbertson, E.G. (1992). Noxious weeds of Australia. (Inkata Press, Melbourne). P74-7. Photos. Diagram.

Wilding, J.L. et al. (1987). Crop weeds. (Inkata Press, Melbourne). P11. Photos. Diagram.

Acknowledgments:

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