Black Flag

Ferraria crispa Burman ex Miller

Synonyms - Ferraria undulata

Family: Iridaceae

Names:

Ferraria recognises the Italian botanist Giovanni-Batista Ferrari (1584-1655)
Crispa refers to the wavy (or crisped) "petals".

Other Names:

Black Flag Iris

Summary:

A succulent, fan-leaved bulbous plant 13-35 cm tall with distinctive black flowers in late spring.

Description:

Cotyledons:

One.

First leaves:

Leaves:

Many, vertically flattened and arranged in 2 rows on either side of the stem and overlapping at the base (equitant)
Stipules - None
Petiole - None
Blade - Green with a bluish hue (glaucous). Broad, long, thick with a with a prominent thickened midrib. Lower leaves are 150-300 mm long x 5-15 mm wide. Tip pointed and often slightly incurved. Sides parallel and smooth. Base sheathing and split where it clasps a leaf on the opposite side of the stem. Hairless.
Stem leaves - graduate into oval floral bracts with white edges.

Stems:

Stout, erect, usually branched and arising from an underground corm.

Flower head:

Many cymes with 2-3 flowers in each spathe.
The spathe is 30-60 mm long, papery with translucent edges, swollen and striped. Outer spathe is shorter than the inner one.
Floral bracts are membranous and attached to the base of the flower stalk (pedicel).
Flowers on short stalks (pedicels) and only remain open for 1 day.

Flowers:

40-50 mm wide. Strong unpleasant odour.
Ovary - inferior, 3 celled.
Style - Single, short, thread-like and within the staminal tube. The 3 style branches, 3-4 mm long, are opposite the stamens, 2 lobed and fringed with short hairs
Perianth - 6 almost equal lobes, spreading, shortly clawed, maroon to black with lighter markings or purple blotched "petals" with greenish, wavy edges and a very short tube. 'Petals' (lobes) 15-20 mm long with 8-10 mm long claws. The limbs broadly triangular, 10-15 mm wide with wavy edges and pointed tips
Stamens - 3 filaments inserted in the perianth tube and symmetrically arranged.
Anthers - 3, black, small, oblong, erect, attached at the base, open outwards with parallel cells and pressed against the style branches

Fruit:

Globular to cylindrical capsule, 15-20 mm long, opening by 3 valves. Many seeds.

Seeds:

Globular and angular. Brown to straw coloured

Roots:

It has a string of brown, flattened globular, underground corms.

Key Characters:

Few, broad, linear, thick leaves.
Inflorescence axis branched.
2-3 pedicellate flowers grouped in cymes surrounded by 2 large spathes.
Perianth segments almost free, maroon to black with undulating margins.
Ovary inferior.
Style branches, small, opposite anthers, deeply divided into 2 segments and densely hairy along the upper margin and not exceeding the stamens within the perianth tube.
3 stamens.
Adapted from J. Black, C. Gardner and G. Perry.

Biology:

Life cycle:

Perennial corms with annual tops from autumn to spring. Flowers emerge successively in spring and are open for 1 day. Each year a new corm is added to the string of previous seasons corms.

Physiology:

Reproduction:

By underground corms.

Flowering times:

July to November in WA.
October to November in SA.
Spring.

Seed Biology and Germination:

Vegetative Propagules:

Underground corms.

Hybrids:

Allelopathy:

Population Dynamics and Dispersal:

Garden escapee. Spreads by seed and corms. Often grows in dense clumps. Spread by birds (Dixon pers comm.)

Origin and History:

South Africa.
Introduced as an ornamental garden plant.

Distribution:

SA, WA. Norfolk Island.
Often on roadsides, rubbish dumps and around old settlements.
Perth to Pingelly and Cape Riche.
Jarrah forest, Swan coastal plain and Warren in WA.

Courtesy Australia's Virtual Herbarium.

Habitats:

Climate:

Temperate, Mediterranean, coastal.

Soil:

Coastal. Grey sandy soils often over limestone.

Plant Associations:

Coastal heath and woodlands.

Significance:

Beneficial:

Ornamental garden plant.

Detrimental:

Invades disturbed bushland.

Toxicity:

Possibly toxic.

Symptoms:

Treatment:

Legislation:

None.

Management and Control:

Control is difficult because of the sting of underground corms that send up new plants when the corm above has been damaged.
Glyphosate and sulfonyl urea herbicides provide control if repeated regularly.

Thresholds:

Eradication strategies:

Dig up isolated plants and carefully collect the string of underground corms. Burn these plants.
Spray with metsulfuron, chlorsulfuron or glyphosate in early winter and repeat in spring for several years. The plant appears to regrow from successively deeper corms after each spraying.

Herbicide resistance:

None reported.

Biological Control:

None available.

Related plants:

Iris, Cape Tulip, Watsonia, Freesia, Gladiolus, Onion (Guildford) Grass, Ixia, Babiana, Sparaxis and the native Patersonia are in the same family.

Plants of similar appearance:

In the vegetative state the leaves look similar to Freesia and Sparaxis but these species have a single, globular mother corm. When flowering it is very distinctive.
Patersonia looks similar in the vegetative state but has a short rootstock rather than flattened corms underground. It has 3 "petal" blue flowers.
Watsonia has much larger leaves.

References:

Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P207. Diagram.

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). P30. Photo.

Lazarides, M. and Cowley, K. and Hohnen, P. (1997). CSIRO handbook of Australian Weeds. (CSIRO, Melbourne). 418.1.

Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P792.

Paczkowska, G. and Chapman, A. (2000). The Western Australia flora: a descriptive catalogue. (Wildflower Society of Western Australia (Inc), the Western Australian Herbarium, CALM and the Botanic Gardens & Parks Authority). P70.

Randall, J.M. and Marinelli, J. (1996) Invasive Plants. (Brooklyn Botanic Gardens Inc. Brooklyn). P. Photo.

Acknowledgments:

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