Poa cookii, sometimes called Cook's tussock-grass or bluegrass, is a species of tussock grass native to various subantarctic islands. The specific epithet honours British explorer James Cook who visited the Kerguelen Islands in 1776.[2]

Poa cookii
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Pooideae
Genus: Poa
Species:
P. cookii
Binomial name
Poa cookii
Synonyms
  • Festuca cookii Hook.f.
  • Poa hamiltonii Kirk

Description

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Poa cookii is a deep green, perennial, gynomonoecious grass growing as densely clumped tussocks up to 800 mm in height, with the fibres from older leaf-sheaths forming a tangled mass at the base of the plant. It is a smaller plant than Poa foliosa with which it may grow. The grass flowers from November to February.[2][3]

Distribution and habitat

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The grass is found on the Prince Edward, Crozet, Heard and Kerguelen Islands of the southern Indian Ocean, as well as on Australia's Macquarie Island. On Heard it occupies moist and sandy areas along the shore and on peat flats with the cushion plant Azorella selago. On Macquarie it grows on rocky areas along the coast up to 200 m above sea level, on flats and slopes on wet peat and along the edges of creeks, often flourishing in the nutrient-rich soil near penguin colonies where it has a competitive advantage over the dominant Poa foliosa. On the Prince Edward Islands Poa cookii is eaten by caterpillars of the native moth Embryonopsis halticella.[4] On Macquarie it has been severely affected by rabbit grazing.[2][3]

References

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  1. ^ Hooker, J.D. (1879). "Enumeration of the plants hitherto collected in Kerguelen Isalnd [sic] by the "Antarctic," "Challenger," and "British Transit of Venus" expenditions - I. - Flowering plants, ferns, lycopodiaceæ, and churaceæ". Philosophical Transactions of the Royal Society. 168: 22. doi:10.1098/rstl.1879.0004. S2CID 186212975.
  2. ^ a b c "Poa cookii (Hook.f.) Hook.f." Flora of Australia Online. Australian Biological Resources Study. 1993. Retrieved 2011-01-20.
  3. ^ a b Bryant, S. L. & Shaw. J.D. (2007). Threatened species assessment on Macquarie Island, Voyage 5, April 2007 (PDF). Report to Biodiversity Conservation Branch, DPIW. Hobart: Department of Primary Industries and Water, Tasmania.
  4. ^ Crafford, J. E.; Scholtz, C. H. (1986). "Impact of Embryonopsis halticella eaton larvae (Lepidoptera: Yponomeutidae) feeding in Marion Island tussock grassland". Polar Biology. 6 (4): 191–196. doi:10.1007/BF00443395. ISSN 0722-4060.