Concept

Crepis

Crepis, commonly known in some parts of the world as hawksbeard or hawk's-beard (but not to be confused with the related genus Hieracium with a similar common name), is a genus of annual and perennial flowering plants of the family Asteraceae superficially resembling the dandelion, the most conspicuous difference being that Crepis usually has branching scapes with multiple heads (though solitary heads can occur). The genus name Crepis derives from the Greek krepis, meaning "slipper" or "sandal", possibly in reference to the shape of the fruit. The genus is distributed throughout the Northern Hemisphere and Africa, and several plants are known as introduced species practically worldwide. The center of diversity is in the Mediterranean. Crepis species are used as food plants by the larvae of some Lepidoptera species including the broad-barred white moth. The fly Tephritis formosa is known to attack the capitula of this plant. Seeds of Crepis species are an important food source for some bird species. Crepis can reproduce sexually or asexually. Crepis is insect-pollinated, typically by bees and other generalist pollinators. Species in this genus are able to produce viable seeds through hybridization. Some of these hybrids (depending on their parent species) can reproduce themselves. As an aster, flowers of Crepis are closely clustered on a capitulum, which is surrounded by petal-like rays. Asexual reproduction (or autogamy) between flowers on the same capitulum has been observed in the genus. As with several other genera in Asteraceae, multiple Crepis species exhibit apomixis, a form of asexual reproduction where flowers produce clonal seeds without need of fertilization. Unlike sexually-reproducing individuals, which are diploid, apomicts are typically polyploid, with three or more sets of chromosomes. The mechanism of apomixis in Crepis is apospory, wherein diploid tissue arises during meiosis in the ovule. Through apospory, asexual seeds can develop spontaneously in the flowers of a non-apomictic Crepis.

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