Cakile is derived from the Arabic name of the plant.
Sea Rocket refers to it rocket shaped pods and its preference for seaside habitats.
Other Names:
Two-horned Sea Rocket refers to the two horns on the seed pod.
Summary:
A lobed and wavy leaved succulent, annual, low, many branched, spreading herb of sea shores with short, fat, 2-segmented pods and 4 petalled, white, pink or purple flowers at any time of the year.
Description:
Cotyledons:
Two. Long and narrow, 10-18 mm long by 3-5 mm wide. Tip rounded. Edges smooth, Base tapered. Hairless. Green or often reddish and turning yellow with age. Petiole short, 3-5 mm long and merging. Stem below cotyledons usually reddish brown. Accumbent (Don't lean on each other).
First leaves:
Paired, long and narrow, 15-30 mm long by 3-8 mm wide. Hairless. The first leaf may have lobes reduced to a few shallow teeth or is lobed like the older leaves. Short merging petiole 5-10 mm long.
Leaves:
Paired
Stipules - None.
Petiole - Short and merging. Hairless.
Blade - Deeply lobed or occasionally entire. 30-100 mm long by 15-40 mm wide and succulent. Lobes usually in several (3-5) pairs, 1.5-5 mm wide and sometimes branched. Base tapered. Hairless.
Stem leaves - Hairless.
Stems:
Branched. Hairless.
Flower stem - Hairless
Flower head:
Tight raceme that elongates as the pods form. No bracts.
Flowers:
White, pink or purple with 4 petals and fragrant.
Ovary - Superior, 2 celled.
Style - Short, thick
Stigma - Small, head like.
Sepals - 4. 3-4 mm long. Erect.
Petals - 4. Pink or purple. 5-14 mm long. Egg shaped. Veined. Very slender claw.
Stamens - 6
Anthers - 2 celled, longitudinally dehiscent to the inside
4 nectary glands
Fruit:
Corky, pod-like, capsule, 14-27 mm long by 4-7 mm wide or smaller if only one seeded. Usually 2 seeded and the upper seed is larger. Constricted just above the top of the lower segment. Lower segment top shaped and expanded to form 2 blunt horns below the constriction. No septum. Doesn't release seed when ripe.
On thick stalks about 4 mm long.
Seeds:
Remain attached to the pod.
Roots:
Long taproot.
Key Characters:
Leaves succulent, hairless.
Petals long-acuminate, not twisted, usually less than twice as long as the sepals.
Fruit a siliqua, longer than broad, not compressed, differentiated into a valve and beak region with a 1 seeded upper segment and usually a 1 seeded lower segment. Upper segment breaks from lower segment but seed is not released from the individual segments. Lower segment horned. Upper segment with a short blunt beak.
Adapted from John Black and B. L. Rye
Biology:
Life cycle:
Annual. Seedlings appear all year depending on rain and are most abundant in spring. Flowers all year.
Physiology:
Reproduction:
Flowering times:
All year.
Seed Biology and Germination:
Vegetative Propagules:
Hybrids:
2 subspecies are recorded ssp. maritima and ssp. baltica which are quite similar.
Allelopathy:
Population Dynamics and Dispersal:
Dispersed by seed.
Origin and History:
North Africa, Europe, North America.
Distribution:
ACT, NSW, SA, TAS, VIC, WA.
Mainly on sandy areas near the coast in southern Australia.
Plant endemic native species then remove weed by manual weeding or selective herbicides such as metosulam.
Thresholds:
Eradication strategies:
Plant endemic native species then remove weed by manual weeding or selective herbicides such as metosulam for several years.
Most of the Brassicaceae weeds have dormant seeds that continue to germinate throughout the season and for several years. They often mature and set seed very quickly. Manual removal is effective but must be done at least every 8-10 weeks. Once pods are formed, seed will often mature even if the plant has been uprooted. Soil disturbance often leads to a flush of seedlings.
Many are somewhat unpalatable, so grazing only offers partial control. They often flourish in undergrazed, sunny areas.
In bushland situations, fairly selective control can be achieved with 100 mL spray oil plus 0.1 g Eclipse® or 0.5 g Logran® in 10 L water. 5 mL Brodal® is often added to this mix to provide residual control of seedlings. Spray the plants until just wet from the seedling stage up to pod formation.
Isolated plants should be removed manually and burnt if flowering or seeding and a 10 m buffer area sprayed with 10 mL Brodal® in 10 L water.
500 mL/ha of glyphosate(450g/L) can be used at flowering to reduce the seed set of most species on roadsides without causing significant damage to most native plants.
Wick application with 1 part glyphosate(450g/L) in 2 parts water or overall spraying with 100 mL glyphosate(450g/L) in 10 L water provides reasonable control of most species though Wild Radish tends to regrow.
Herbicide resistance:
None reported.
Biological Control:
Related plants:
American Sea Rocket (Cakile edentula) has smaller flowers less deeply lobed leaves and somewhat cylindrical lower fruit segment and occurs on the southern Queensland coast and near Eucla on the south Coast.
The native Brassicaceae species usually have short, broad and smooth pods.
Plants of similar appearance:
References:
Auld, B.A. and Medd R.W. (1992). Weeds. An illustrated botanical guide to the weeds of Australia. (Inkata Press, Melbourne). P131-132. Photo.
Black, J.M. (1965). Flora of South Australia. (Government Printer, Adelaide, South Australia). P388.
Bodkin, F. (1986). Encyclopaedia Botanica. (Angus and Robertson, Australia).
Everist, S.L. (1974). Poisonous Plants of Australia. (Angus and Robertson, Sydney).
Harden, Gwen J. (1991). Flora of NSW. (Royal Botanic Gardens, Sydney). Volume . P. Diagram.
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). P116. 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). #166.2.
Marchant et al (1987). Flora of the Perth Region. (Western Australian Herbarium, Department of Agriculture, Western Australia). P162.
Acknowledgments:
Collated by HerbiGuide. Phone 08 98444064 or www.herbiguide.com.au for more information.