capeweed
(Arctotheca calendula)
This species is Introduced in the United States
ORIGIN: South Africa
GROWTH TRAITS: Low-growing, herbaceous, winter annual to perennial with a stoloniferous root system. Stems are hairy, ribbed, and creep on top of or just below the surface, rooting at nodes and forming new rosettes. Stems can reach up to 9’ long (2¾ m) in a single growing season and form a dense groundcover. Leaves are 2-10” long (5-25 cm) and deeply and irregularly lobed. Leaves are bright green and slightly hairy above; they are densely hairy and white beneath. Flowering occurs nearly year-round but peaks in spring. Flower heads are ~2” in diameter (5 cm) and occur singly on hairy stalks 6-8” tall (15-20 cm). Outer florets (<20) are petal-like, sterile, and yellow with purple-tinged bases. Inner florets are numerous, tiny, and dark purple or yellow. Inner florets produce oval, brown achenes, each surrounded by a dense tuft of light, woolly hairs. Seeds are sterile in the infertile form of the plant frequently used in landscaping.
REPRODUCTION: Infertile form spreads only via stolons. Fertile form spreads with seeds and stolons. Seed viability is unknown.
HABITAT: Found in disturbed areas with well-drained soil and full sun including coastal sites, vacant urban areas, riparian zones, and roadsides. Tolerates wet or dry soils, but is limited by frost.
LOOK-ALIKES: The large flower heads with yellow outer florets and tiny, usually darker, inner florets help set this species apart from many others in the Asteraceae family. It can be differentiated from most remaining look-alikes by being very low-growing and having deeply lobed leaves. Cape marigold (Dimorphotheca sinuata) is a winter annual that has also escaped cultivation. Cape marigold sometimes has similar yellowish flowers with purple-tinged florets and can form dense infestations. Cape marigold does not have stolons, or hairy leaf undersides, or woolly hairs around seeds.
CITATIONS:
Winston, R.L., Andreas, J.E., Milan, J., DesCamp, W., Randell, C.B., and M. Schwarzlander. 2014. New Invaders of the Southwest. United States Department of Agriculture, Forest Health Technology Enterprise Team. FHTET-2014-12. Retrieved from https://bugwoodcloud.org/resource/files/14767.pdf
GROWTH TRAITS: Low-growing, herbaceous, winter annual to perennial with a stoloniferous root system. Stems are hairy, ribbed, and creep on top of or just below the surface, rooting at nodes and forming new rosettes. Stems can reach up to 9’ long (2¾ m) in a single growing season and form a dense groundcover. Leaves are 2-10” long (5-25 cm) and deeply and irregularly lobed. Leaves are bright green and slightly hairy above; they are densely hairy and white beneath. Flowering occurs nearly year-round but peaks in spring. Flower heads are ~2” in diameter (5 cm) and occur singly on hairy stalks 6-8” tall (15-20 cm). Outer florets (<20) are petal-like, sterile, and yellow with purple-tinged bases. Inner florets are numerous, tiny, and dark purple or yellow. Inner florets produce oval, brown achenes, each surrounded by a dense tuft of light, woolly hairs. Seeds are sterile in the infertile form of the plant frequently used in landscaping.
REPRODUCTION: Infertile form spreads only via stolons. Fertile form spreads with seeds and stolons. Seed viability is unknown.
HABITAT: Found in disturbed areas with well-drained soil and full sun including coastal sites, vacant urban areas, riparian zones, and roadsides. Tolerates wet or dry soils, but is limited by frost.
LOOK-ALIKES: The large flower heads with yellow outer florets and tiny, usually darker, inner florets help set this species apart from many others in the Asteraceae family. It can be differentiated from most remaining look-alikes by being very low-growing and having deeply lobed leaves. Cape marigold (Dimorphotheca sinuata) is a winter annual that has also escaped cultivation. Cape marigold sometimes has similar yellowish flowers with purple-tinged florets and can form dense infestations. Cape marigold does not have stolons, or hairy leaf undersides, or woolly hairs around seeds.
CITATIONS:
Winston, R.L., Andreas, J.E., Milan, J., DesCamp, W., Randell, C.B., and M. Schwarzlander. 2014. New Invaders of the Southwest. United States Department of Agriculture, Forest Health Technology Enterprise Team. FHTET-2014-12. Retrieved from https://bugwoodcloud.org/resource/files/14767.pdf
Selected Images
Maps
EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org
State Lists - This map identifies those states that have this species on their invasive species list or law.
Invasive Listing Sources
Taxonomic Rank
| Domain: Eukarya |
| Kingdom: Plantae |
| Phylum: Magnoliophyta |
| Class: Magnoliopsida |
| Superorder: Asteranae |
| Order: Asterales |
| Family: Asteraceae |
| Subfamily: Cichorioideae |
| Tribe: Arctotideae |
| Genus: Arctotheca |
| Arctotheca calendula |
References
Common Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.
Scientific Name Reference: USDA, NRCS. 2010. The PLANTS Database. National Plant Data Center, Baton Rouge, LA, USA.