Sisyrinchium bermudiana (Blue-eyed grass)

Kingdom:   Plantae
Clade:       Angiosperms
Clade:       Monocots
Order:       Asparagales
Family:      Iridaceae
Genus:      Sisyrinchium
Species:     S. bermudiana
Binomial name:  Sisyrinchium bermudiana
Common name: Blue-eyed grass,  Bermudiana, Feilistrín gorm

Sisyrinchium bermudiana is a perennial plant of the Sisyrinchium genus (of the iris family). Is a small, tufted perennial of wet pastures, lake shores and grass verges that is widespread in North America and has its European presence principally in Northern Ireland.
Flowers are produced during spring and each one lasts only a day or two. The small, star-like, pale to bright blue flowers have contrasting yellow centres. They open only in bright sunlight.
Sisyrinchium bermudiana usually grows to 20 cm in height but can sometimes reach 40 cm.
In good growing conditions, blue-eyed grass can become locally abundant, spreading in an invasive weedy manner. The plant often possesses a short thickened, horizontal underground stem which provides food storage over the winter period, and this also allows the individual plant to increase in size and form a tight clump.

Photographed at Tupare Gardens, New Plymouth
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Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/