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Poa bulbosa; photograph (c) cigazze, some rights reserved (CC BY) CC BY(c) cigazze, some rights reserved (CC BY) · observed growing wild · 2026-09-11

Poa bulbosa L.

Bulbous meadow-grass; Bulbous bluegrass; Bulbous poa; Bulbous speargrass

Poaceae · Denmark, Finland +67

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Poa bulbosa, photograph (c) cigazze, some rights reserved (CC BY)Poa bulbosa, photograph (c) ivansemenkov, some rights reserved (CC BY)Poa bulbosa, photograph (c) ivansemenkov, some rights reserved (CC BY)Poa bulbosa, photograph (c) ivansemenkov, some rights reserved (CC BY)Poa bulbosa, photograph (c) ivansemenkov, some rights reserved (CC BY)Poa bulbosa, photograph (c) ivansemenkov, some rights reserved (CC BY) 62 photographs ›
Habitat figures
Cold floor (1 night in 100)
-11.1°C
Record low -23.3 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
27°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
622mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
8–40DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Rain spread: 70% of the median year's rain takes 8 months, so no short rainy season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Poa bulbosa is a species of grass known by the common names bulbous bluegrass or bulbous meadow-grass. It is native to Eurasia and North Africa, but it is present practically worldwide as an introduced species. It is widespread in the United States and southern Canada. It was introduced to the eastern United States around 1906 and the western US in 1915 as a contaminant in shipments of alfalfa seed. More on Wikipedia ›

Quoted from Wikipedia, "Poa bulbosa", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (437 mm of 614 mm) takes 8 months, May to December. Mean temperature moves 21.7 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to June.

Rain

614 mm in the median year at the habitat, 437 mm of it May to December. Wettest month June at 63 mm, driest month February at 41 mm. Across the grid cells of the range the year's total runs 376 mm to 971 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 622 mm, is the year's rain at the top of the page; the 614 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 8 to 40 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA; the lowest 10th-percentile month across the cells is 4, the highest 90th-percentile month 50).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -11.1 °C, the absolute minimum -23.3 °C, 3,566 frost nights in 44 years, 81.0 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 38.2 °C. Monthly means: the coldest month's mean nightly low -2.3 °C in January (across the grid cells of the range -6.4 °C to 5.0 °C), the warmest month's mean daily high 26.7 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -11.1 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 56 to 66% across the year (monthly means, median year across the grid cells of the range, CHELSA). A figure about the air, saying nothing about how the plant takes water.

How this section is made

Each card states this species' habitat figures with their sources, and what two fixed rules read from them; nothing here says what the plant does, wants or tolerates. The rules · the terms.

Seasons. Read from the median year of CHELSA monthly rainfall and mean temperature across the grid cells of the range: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve moves 4 °C or more and the habitat lies 10° or more from the equator. A reading of the curves, not an observation of the plant.

Rain. CHELSA monthly precipitation, median year across the grid cells of the range. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light. CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Temperature. NASA POWER daily minima and maxima over 44 years at a typical spot in the range, lapse-corrected -103 m to its elevation; CHELSA monthly means, median year across the grid cells of the range. The cold floor is the 1st-percentile night named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity. CHELSA relative humidity, median year across the grid cells of the range.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Poa bulbosa through the yearWarmest months July and August, mean daily high 27 °C; coldest month January, mean nightly low -2.3 °C; 614 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, northern hemisphere.-40°-20°0°20°40°frost38.2° 99th-percentile day, NASA POWER-23.3° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125mm rainDLI 8–40RH 56–66%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 403 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C4 / -1–125 / 0–1310 / 6–1715 / 12–2020 / 17–2524 / 21–3027 / 23–3227 / 23–3222 / 18–2816 / 13–2110 / 5–175 / 0–14
Night °C-2 / -6–5-2 / -7–51 / -2–76 / 3–1011 / 8–1415 / 12–1817 / 14–2117 / 14–2113 / 10–188 / 5–153 / 0–10-1 / -5–7
Rain mm46 / 26–10441 / 25–9146 / 28–7744 / 26–9459 / 23–9663 / 7–8751 / 3–8251 / 2–7951 / 6–9847 / 24–11056 / 32–10759 / 31–118
DLI9 / 6–1815 / 11–2423 / 18–3331 / 28–4037 / 34–4540 / 36–5040 / 35–4935 / 30–4526 / 20–3717 / 12–2710 / 6–198 / 4–15
RH %65 / 58–6862 / 57–6660 / 55–6357 / 53–6157 / 52–6057 / 50–6056 / 49–5956 / 49–6058 / 51–6161 / 54–6464 / 55–6766 / 57–69
How this section is made
Each figure is the median across the 403 grid cells on land that hold in-range records (544 records in those cells; 11 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are left out), with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 906:4018 (44.675, 20.925). Over 44 years there: absolute minimum -23.3 °C, 1st-percentile night -11.1 °C, 99th-percentile day 38.2 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 403 distinct grid cells holding 544 of the 555 in-range records (11 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 906:4018 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 44.50_20.625, lapse-corrected -103 m at 6.5 °C/km. Elevation: ETOPO 2022, 80 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeDenmark, Finland, Great Britain, Ireland, Norway, Sweden, Austria, Belgium, Czechoslovakia, Germany, Hungary, Netherlands, Poland, Switzerland, Baleares, Corse, France, Portugal, Sardegna, Spain, Albania, Bulgaria, Greece, Italy, Kriti, Romania, Sicilia, Turkey-in-Europe, Yugoslavia, Baltic States, Krym, Central European Russia, East European Russia, North European Russia, South European Russia, Northwest European Russia, Ukraine, Algeria, Libya, Morocco, Tunisia, Canary Is., Madeira, Sudan, Cape Provinces, Altay, Kazakhstan, Kirgizistan, Turkmenistan, Tadzhikistan, Uzbekistan, North Caucasus, Transcaucasus, Afghanistan, Cyprus, East Aegean Is., Iran, Iraq, Lebanon-Syria, Palestine, Turkey, Gulf States, Oman, Saudi Arabia, Tibet, Xinjiang, Nepal, Pakistan, West Himalaya · introduced: Korea, New South Wales, South Australia, Tasmania, Victoria, Western Australia, New Zealand South, Alberta, Colorado, Idaho, Montana, Oregon, Washington, Wyoming, Illinois, Iowa, Kansas, Minnesota, Missouri, North Dakota, Nebraska, Oklahoma, South Dakota, Wisconsin, Connecticut, Indiana, Massachusetts, Michigan, New Jersey, New York, Ohio, Pennsylvania, Vermont, West Virginia, Arizona, California, Nevada, Utah, New Mexico, Texas, Arkansas, Delaware, Georgia, Kentucky, Louisiana, Maryland, North Carolina, Tennessee, Virginia, Argentina South, Chile South · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker47.551, 18.989 · in the densest population, 118 records (21% of those in range)
Kew's description“perennial or bulbous geophyte” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 564 georeferenced records inside the native range; the climate across the range on the 544 of them in the land cells it reads, of 555 placed to within 10 km; the map shows only the 85 openly licensed ones, which alone would put the marker 768 km away. 222 records outside the WCVP native range not used. 9 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 564 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Poa bulbosa, photograph 1did not loadPoa bulbosa, photograph 2did not loadPoa bulbosa, photograph 3did not loadPoa bulbosa, photograph 4did not loadPoa bulbosa, photograph 5did not loadPoa bulbosa, photograph 6did not load

Photographs: (c) cigazze, some rights reserved (CC BY); (c) ivansemenkov, some rights reserved (CC BY) (5).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Paeonia peregrina Paeonia peregrina Scarlet peony Photo: CC BY, Salza PalpurinaOnosma arenaria Onosma arenaria Golden Drop Photo: CC BY-SA, Selchuk SyuleymanCrocus flavus Crocus flavus Yellow crocus Photo: CC BY, ajottKnautia macedonica Knautia macedonica Macedonian scabious Photo: CC0, author not stated Satureja coerulea Lamiaceae Hibiscus trionum Hibiscus trionum Bladder ketmia Photo: CC BY-SA, Tony Rebelo

Other Poa 30 in the reference

Poa alpina Poa alpina Alpine meadow-grass Photo: CC BY, Matt BergerPoa alsodes Poa alsodes Grove bluegrass Photo: CC BY, Summit Metro ParksPoa anceps Poa anceps Poaceae Photo: CC BY, Hannah RogersPoa angustifolia Poa angustifolia Narrow-leaved meadow-grass Photo: CC BY, Oleksii VasyliukPoa annua Poa annua Annual bluegrass Photo: CC0, author not statedPoa arachnifera Poa arachnifera Texas bluegrass Photo: CC BY, Cody StrickerPoa araratica Poa araratica Poaceae Photo: CC BY-SA, Krzysztof Ziarnek, KenraizPoa badensis Poa badensis Baden's bluegrass Photo: CC BY, arthur_haendlerPoa buchananii Poa buchananii Scree poa Photo: CC BY, Ian DickiePoa cenisia Poa cenisia Poaceae Photo: CC BY, Ana GarciaPoa chaixii Poa chaixii Broad-leaved meadow-grass Photo: CC0, author not statedPoa cita Poa cita Silver tussock Photo: CC BY, Colin Meurk all 31 ›

Names & registers

Also known as Paneion bulbosum; Paneion bulbosum var. viviparum; Poa alpina f. vivipara; Poa attenuata var. desertorum; Poa briziformis and 44 more. (GBIF Backbone)

Kew accepts as species of their own Poa carniolica: older names in GBIF's record of this species that Kew's World Checklist accepts as other species. (WCVP, RBG Kew, file of 2026-06-04)

Under another author Poa alpina Pall. and Poa alpina Pall. ex Roem. & Schult. is an older name of this species, not Poa alpina, a species of the reference; Poa compressa Schrenk and Poa compressa Schrenk ex Griseb. and Poa compressa Schrenk ex Ledeb. is an older name of this species, not Poa compressa, a species of the reference. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Poaceae
Described by
L.
Native to
Denmark, Finland, Great Britain +66
Wild records
564 in range · 85 open

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-22
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredasked 2026-10-22GBIF occurrence search API; 51 records within 1 km of a botanic garden, herbarium or zoo left out (32 at a botanic garden or arboretum, 6 at a herbarium, 13 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 44.50_20.625, lapse-corrected -103 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by its label; its POWO identifier 320038-2 is Kew's for Poa bulbosa L.
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild answeredasked 2026-10-22from iNaturalist's open data of 2026-09-27: research-grade observations with an open-licence photograph, the 24 whose photographs iNaturalist received last (the open data holds no votes); filled 2026-10-22
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-22
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 7 datasets via GBIF.org; each carries its own licence.

Cultifolio

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