Yellow fist opener. Annual or biennial herb, whitish due to hairiness, belonging to the genus Centaurea of the compound family.
Summary
[ hide ]
- 1 Habitat and Distribution
- 2 Description
- 3 Flowering
- 4 Care
- 5 Multiplication
- 6 Uses
- 7 Propagation Data
- 8 Sources
Habitat and distribution
It grows in grasslands and somewhat nitrified open places. It is native to the Mediterranean region of Europe , North and West Africa , and Macaronesia . It was introduced to North America in the 18th century: the first documented appearance in California is in the adobe of a building built in San Fernando in 1797. In this region it has become an invasive pest that is practically impossible to eradicate in the entire United States . It is also naturalized on a number of Pacific islands, and practically the entire world.
Description
It is an annual species, 10 to 100 cm high, with superiorly branched stems, leaves with resins, and alternate fillarial-type spines, the basal petioles with sinuate and lobed or pinnate limbs, the caulinars seated and linear lanceolate. Flowers in homogamous discoid chapters, solitary or in terminal groups. Chapters with involvement of arachnoid bracts; the outer and middle ones with a spiny appendage. This appendix has a terminal spine and several pairs of lateral spines. The fruits are achenes with a scaly vilane almost as long as the achene and with eleosome .
Flowering
Yellow capitula with alternate spines that appear in summer.
Care
- IRRIGATION: nothing
- PRUNING: mow at the end of summer.
- LIGHT: full sun
- SOIL: sandy and heavy
Multiplication
It multiplies by seeds. Self sows with ease.
Applications
Plant of low ornamental value (3) Useful properties: Weed
Propagation Data
This species has the following resistance to cold: Plant does not resist snow, but it resists occasional non-prolonged frosts up to approx. -5 ° C (the typical morning frosts). Equivalent to USDA Climate Zone 9.
