Крепис өсімдігінің сипаттамасы мен ерекшеліктері

Genus of flowering plants in the family Asteraceae
the genus of plant

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. 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. Crepis is part of the Cichorieae tribe in Asteraceae, and is one of several genera of that tribe that exhibits apomixis. The largest group of asexual species is found in North America, and is referred to as the "North American Crepis agamic complex" At least one Eurasian Crepis species, C. tectorum, has been observed to self fertilize. Species known to produce apomicts include C. acuminata, C. barbigera, C. intermedia, and C. occidentalis. Polyploid individuals may still be able to carry out sexual reproduction and therefore produce sexual offspring, allowing for the formation of new polyploid hybrids. The mixed apomict sexual parantage may produce a polyploid hybrid (as has been observed when the apomictic C. barbigera breeds with diploid species C. atribarba). Seed set in the diploid may be reduced, or the pollen may produce hybrid seeds that are unable to reproduce or survive to a normal lifespan. The pollen from the apomict may also prevent germination of pollen from a diploid flower. When pollen from a polyploid individual fertilizes diploid flowers, the resultant seeds are typically polyploid, which lowers the diploid population over generations. Additionally, some Crepis apomict species have the ability to hybridize with other apomicts, resulting in genetic recombination alongside parthenogenesis.

In Crete, Greece the leaves of Crepis commutata which are called glykosyrida (γλυκοσυρίδα) are eaten raw, boiled, steamed or browned in salads. Another two species on the same island, Crepis vesicaria, called kokkinogoula (κοκκινογούλα), lekanida (λεκανίδα) or prikousa (πρικούσα) and a local variety called maryies (μαργιές) or pikrouses (πικρούσες) have both its leaves and tender shoots eaten boiled by the locals.

The genus Crepis is a rich source of costus lactone type guaianolides, a class of sesquiterpene lactones. Phenolics found in Crepis include luteolin type flavonoids and caffeoyl quinic acid derivatives such as chlorogenic acid and 3,5 dicaffeoylquinic acid. Moreover, Crepis species contain the caffeoyl tartaric acid derivatives caffeoyl tartaric acid and cichoric acid.