Capeweed [Arctotheca calendula (L.) Levyns][Bayer code: none][CDFA list: A][CalEPPC: Red alert] Photographs Map of Distribution

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SYNONYMS: cape dandelion, cape gold, Arctotis calendula L., Arctotheca calendulaceum (L.) Lewin, Cryptostemma calendula (L.) Druce

GENERAL DESCRIPTION: Rosette-forming perennial with creeping stolons or winter annual, to 0.3 m tall. Capeweed is often grown as an ornamental groundcover. Most plants in the horticultural trade are derived from a single sterile individual and reproduce vegetatively. However, noxious seed-bearing types have been introduced into California and have escaped cultivation in some areas. Seed-bearing plants typically colonize open sites with exposed soils. Sterile plants sometimes escape cultivation, but are much less invasive than seed-bearing plants. Capeweed is perennial in areas with a mild frost-free mediterranean climate, such as coastal California. Seed-bearing plants are annual elsewhere, including capeweed’s native range and southern Australia, where it is an abundant pasture weed. Certain capeweed populations in Australia have developed resistance to bipyridylium herbicides. Handling plants can cause contact dermatitis on sensitive individuals. Introduced from South Africa.

SEEDLINGS: Cotyledons spoon-shaped, glabrous. First leaves appear opposite, narrowly oblong with deeply lobed margins. Lobes broadly acute to rounded. Terminal lobe larger than lateral lobes, typically rounded. Upper surfaces sparse to moderately covered with white hairs. Lower surfaces densely covered with white woolly hairs. Subsequent leaves alternate, similar to first leaves.

MATURE PLANT: Rosette leaves +/- oblanceolate, deeply pinnate- to +/- bipinnate-lobed, 5-25 cm long, 2-6 cm wide. Lobes irregularly toothed to lobed, teeth and lobe apices +/- acute, often tipped with a short bristle. Upper surfaces glabrous to moderately covered with fine white cobweb-like hairs. Lower surfaces white, densely covered with white woolly hairs. Leaves on flowering stems 0-few, alternate, much reduced, sessile, clasping stem, pinnate-lobed to nearly entire.

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ROOTS and UNDERGROUND STRUCTURES: Stolons creeping, rooting at nodes, often vigorous. One plant can spread to cover up to 18 m2 (200 ft2) in 1-2 years.

FLOWERS: Most of year, peaking March-June. Heads +/- 5 cm in diameter, solitary on hairy stalks ~ 15-20 cm long. Receptacle flat, lacks chaff (bracts). Phyllaries strongly overlapping (imbricate) in 3-6 rows, green, with membranous margins and tips curved backwards (reflexed), covered with woolly hairs. Ray flowers sterile, less than 20. Ray corollas 15-25 mm long, pale yellow in upper half, sometimes darker yellow below, purple or greenish at the base. Disk flowers dark purplish or yellow, numerous. Pappus scales 6-8, +/- 1 mm long.

FRUITS and SEEDS: Achenes ovate, flattened, ~2-4 mm long. Surface longitudinally 3-5-ribbed, laterally wrinkled, but hidden by a dense ball of long pale (pinkish-)brown woolly hairs.

POSTSENESCENCE CHARACTERISTICS: Plants break-apart rapidly when desiccated.

HABITAT: Disturbed coastal and urban sites. Tolerates drought. Grows best on well-drained soils. Plants are damaged by frosts a few degrees below freezing and are killed by colder temperatures.

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DISTRIBUTION: Escaped populations are uncommon. North Coast, San Francisco Bay region. To 250 m (820 ft).

PROPAGATION/PHENOLOGY: Reproduces by seed and/or vegetatively from stolons. The biology of capeweed is poorly understood. Seeds disperse with human activities, animals, and probably wind. Seedlings tolerate dry conditions.

MANAGEMENT FAVORING/DISCOURAGING SURVIVAL: In pastures, mowing and close grazing can increase the ratio of capeweed to desirable vegetation. Shallow cultivation can eliminate seedlings.

SIMILAR SPECIES: Cape marigold or African daisy [Dimorphotheca sinuata DC.][Bayer code: none] is a winter annual with orange to yellow ray flowers, sometimes with violet tips or bases, and yellow disk flowers that has escaped cultivation and may be confused with capeweed. Unlike capeweed, cape marigold has phyllaries in 1 row, flowers that lack a pappus, smooth and tubercled achenes without woolly hairs, foliage covered with glandular hairs, and leaves that lack a dense covering of white woolly hairs. Cape marigold occurs along roadsides and in disturbed areas of the San Joaquin Valley, western South Coast Ranges, South Coast, and Peninsular Ranges. To 1000 m (3300 ft). Introduced from South Africa.


Prevention: Capeweed was originally introduced to California from a single sterile clone and primarily spreads vegetatively from horticultural plantings. However, plants producing viable seed have been found from other more recent introductions. To prevent spreading capeweed into sensitive wildland habitat, use other noninvasive horticultural species when landscaping near the urban wildland interface, preferrably native species. If capeweed must be used, be sure to check that you are using the sterile clone that does not produce seed.

Mechanical: Hand removal with a hoe has been one of the primary methods used for capeweed eradication. Starting at the edge of a patch, work inwards, removing plants rooted at the nodes on each stolon. Some resprouting will occur from missed tubers or crowns, so a follow up removal will likely be necessary. Broken stems may root if left on the soil surface in moist areas. Where possible, tractor mounted scraper blades may also be used to remove dense infestations. However, this results in complete disturbance of the plant community, but may be efficient in badly infested areas.

Biological: There are no registered biological agents for capeweed control and it appears to be rarely used by native California wildlife. Some insects, diseases, and invertebrates may occasionally cause minor damage to plants but with no long term adverse effects.

Chemical: A 3% v/v solution of glyphosate has been used to control large infestations of capeweed. Repeated applications may be necessary for complete eradication. A bypyridylium herbicide resistant biotype has been reported from Australia but has not been reported to occur in California.

Prescribed fire: No information has been reported on the use of fire for capeweed control.

Bossard, C. C., J. M. Randall, and M. C. Hoshovsky, Eds. 2000. Invasive Plants of California's Wildlands. University of California Press, Berkeley, CA. Pp 49-53.
Broom, D.M. and G.W. Arnold, 1986. Selection by grazing sheep of pasture plants at low
herbage availability and responses of the plants to grazing. Australian Journal of
Agricultural Research 37(5):527-538.
Chaharsoghi, A.T. and B. Jacobs, 1998. Manipulating dormancy of capeweed
(Arctotheca calendula L.) seed. Seed Science Research 8(2):139-146.
Dunbabin, M.T. and P.S. Cocks, 1999. Ecotypic variation for seed dormancy contributes
to the success of capeweed (Arctotheca calendula) in Western Australia. Australian
Journal of Agricultural Research 50(8):1451-1458.
Fuerst, E.P. and K.C. Vaughn, 1990. Mechanisms of Paraquat Resistance. Weed
Technology 4(1):150-156.
Powles, S.B., E.S. Tucker, and T.R. Morgan, 1989. A capeweed (Arctotheca calendula)
biotype in Australia resistant to bipyridyl herbicides. Weed Science 37(1):60-62.
Powles, S.B. and P.D. Howat, 1990. Herbicide-Resistant Weeds in Australia. Weed
Technology 4(1):178-185.
Preston, C., S. Balachandran, and S.B. Powles, 1994. Investigations of mechanisms of
resistance to bipyridyl herbicides in Arctotheca calendula (L.) Levyns. Plant Cell and
Environment 17(10):1113-1123.
Turner, N.C., C.J. Thomson, and H.M. Rawson, 2001. Effect of temperature on
germination and early growth of subterranean clover, capeweed and Wimmera ryegrass.
Grass and Forage Science 56(2):97-104.
Wood, H., 1994. The introduction and spread of capeweed, Arctotheca calendula (L.)
Levyns (Asteraceae) in Australia. Plant Protection Quarterly 9(3):94-100.

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