''Poa infirma'' is a species of
grass
Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns an ...
known by the common names early meadow-grass
and weak bluegrass. It was first described from a specimen found in
Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
, but it is actually an
introduced species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there ...
in the Americas and is native to Europe.
[Grass Manual Treatment]
/ref> It grows in many types of habitat, including disturbed areas. It is very similar to ''Poa annua
''Poa annua'', or annual meadow grass (known in America more commonly as annual bluegrass or simply poa), is a widespread low-growing turfgrass in temperate climates. Notwithstanding the reference to annual plant in its name, perennial bio-types ...
'', which is probably a daughter species,[ and it is often mistaken for ''P. annua'' unless it is closely examined.][Chester, T]
Plants of Southern California: ''Poa annua'' and ''P. infirma''
/ref>
This is a small, densely tufted annual grass growing up to tall. It has thin, soft-haired, yellow-green leaves. The inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
is a series of branches bearing flattened spikelets which have tufts of curly hairs.
References
Further reading
* Takagi-Arigho, Ray (1994
''Poa infirma'' - Flourishing? ... or Fleeing?
''BSBI News
The Botanical Society of Britain and Ireland (BSBI) is a scientific society for the study of flora, plant distribution and taxonomy relating to Great Britain, Ireland, the Channel Islands and the Isle of Man. The society was founded as the Botani ...
'' 65:14-18 (gives details of the plant's status and habitat in southwest England)
External links
Jepson Manual Treatment
USDA Plants Profile
infirma
Flora of Europe
Flora of Western Asia
Flora of China
{{Pooideae-stub