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Blechnum durum; photograph Peter de Lange, CC0, via Wikimedia Commons CC0Peter de Lange, CC0, via Wikimedia Commons

Blechnum durum (T.Moore) C.Chr.

Aspleniaceae · Antipodean Is., Chatham Is. +2

English names not checked: Wikidata's common names were not read for this page.

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Blechnum durum, photograph Heidi Meudt, CC BY 4.0, via Wikimedia Commons 2 photographs ›
Habitat figures
Coldest month, mean nightly low
5.8°C
Jul at the habitat, not a floor; extremes not used (sea cell) CHELSA
Warmest month, mean daily high
15°C
Jan, Feb and Mar at the habitat CHELSA
Rain a year (median across the range)
1,241mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
7–39DLI
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 9 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

Austroblechnum durum, synonym Blechnum durum, is a species of fern in the family Blechnaceae. The fern is endemic to New Zealand.

Quoted from Wikipedia, "Austroblechnum durum", CC BY-SA 4.0; its title is one of this species' older names (GBIF Backbone), which is the proof that the article is this species'.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (971 mm of 1,252 mm) takes 9 months, December to January, March to June and August to October. Mean temperature moves 6.3 °C between the warmest and coldest month. Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: February to April, June to July and September to December.

Rain

1,252 mm in the median year at the habitat, 971 mm of it December to January, March to June and August to October. Wettest month January at 120 mm, driest months (2 at 92 mm). Across the grid cells of the range the year's total runs 931 mm to 1,837 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,241 mm, is the year's rain at the top of the page; the 1,252 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, southern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 7 to 39 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 43).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low 5.8 °C in July (across the grid cells of the range 4.1 °C to 8.7 °C), the warmest month's mean daily high 15.3 °C in February (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 5.8 °C, the coldest month's mean nightly low, July, in the median year (CHELSA); a month's mean of its nightly lows is warmer than the nights a floor is read from. The daily extremes were read at a weather cell that is mostly sea and are not used.

Humidity

Relative humidity at the habitat: 62 to 64% 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. CHELSA monthly means, median year across the grid cells of the range. No cold floor is read without a daily extremes series; the coldest month's mean nightly low named in its sentence is not one. 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, southern hemisphere

Habitat climate of Blechnum durum through the yearWarmest months January, February and March, mean daily high 15 °C; coldest month July, mean nightly low 5.8 °C; 1,252 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, southern hemisphere.0°5°10°15°20°°C · day and nightcold quarter050100150200mm rainDLI 7–39RH 62–64%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 58 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C15 / 10–1715 / 10–1715 / 10–1613 / 9–1411 / 8–139 / 7–119 / 7–1010 / 7–1011 / 7–1111 / 7–1312 / 8–1414 / 9–16
Night °C12 / 8–1412 / 8–1411 / 8–149 / 7–127 / 6–116 / 4–96 / 4–96 / 4–97 / 4–98 / 5–109 / 6–1110 / 7–12
Rain mm120 / 60–15792 / 69–118112 / 83–144106 / 76–149116 / 91–168115 / 84–16697 / 80–15498 / 83–143101 / 73–16099 / 66–17592 / 64–151104 / 68–161
DLI38 / 34–4232 / 28–3523 / 19–2615 / 11–179 / 6–117 / 4–88 / 5–1013 / 10–1520 / 17–2329 / 26–3136 / 34–4039 / 37–43
RH %64 / 61–6864 / 61–6763 / 62–6863 / 61–6863 / 61–6763 / 61–6662 / 60–6662 / 61–6662 / 61–6663 / 61–6763 / 60–6664 / 61–68

The daily extremes were read at a NASA POWER cell that is 28% land: neither it nor the next candidates whose coldest month's mean nightly low is within 2 °C of the median across cells sit in a POWER cell that is mostly land, and the rule reads a cold floor only from a cell that is mostly land, so none is read for this species. Nor is the coldest month's mean nightly low taken as one: it is a mean of a month's lows, not its coldest night. What that cell gave over 44 years: absolute minimum 3.4 °C, 1st-percentile night 6.0 °C, 99th-percentile day 20.4 °C.

How this section is made
Each figure is the median across the 58 grid cells on land that hold in-range records (126 records in those cells; 3 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 2672:6988 (-43.625, 169.425). 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 58 distinct grid cells holding 126 of the 133 in-range records (3 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 2672:6988 (its coldest month's mean nightly low nearest the median across cells, though its NASA POWER cell is only 28% land and none of the 11 next candidates within 2 °C of the median was mostly land); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell -43.50_169.375, lapse-corrected -59 m at 6.5 °C/km. Elevation: ETOPO 2022, 65 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.

This species has no GBIF key of its own. Its records are GBIF's under the key of the name Kew's World Checklist holds as this plant: 9305542 (Austroblechnum durum (T.Moore) Gasper & V.A.O.Dittrich, 362 records). No name was matched to GBIF; the keys are read from Kew's synonymy. How.

NativeAntipodean Is., Chatham Is., New Zealand North, New Zealand 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 marker-46.815, 168.233 · in the densest population, 151 records (62% of those in range)
Kew's description“temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 243 georeferenced records inside the native range; the climate across the range on the 126 of them in the land cells it reads, of 133 placed to within 10 km; the map shows only the 180 openly licensed ones, which alone would put the marker 50 km away. 26 records outside the WCVP native range not used. 110 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.
Other GBIF keysRecords also from GBIF's key 9305542 (Austroblechnum durum (T.Moore) Gasper & V.A.O.Dittrich): Kew's file holds it as Austroblechnum durum (T.Moore) Gasper & V.A.O.Dittrich (synonym under Blechnum durum (T.Moore) C.Chr.); 362 records, from GBIF's download.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 2° block of the 243 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Blechnum durum, photograph 1did not load

Photographs: Heidi Meudt, CC BY 4.0, via Wikimedia Commons.

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

Libertia peregrinans Libertia peregrinans Iridaceae Photo: CC BY, Irisa HudsonMyosotis rakiura Myosotis rakiura Boraginaceae Photo: CC BY, Irisa HudsonMacrolearia angustifolia Macrolearia angustifolia Asteraceae Photo: CC BY, Pieter PelserCrassula moschata Crassula moschata Native stonecrop Photo: CC BY, Julia PalmerRumex neglectus Rumex neglectus Shore Dock Photo: CC BY, Irisa HudsonBrachyglottis rotundifolia Brachyglottis rotundifolia Muttonbird scrub Photo: CC0, author not stated

Other Blechnum 52 in the reference

Blechnum appendiculatum Blechnum appendiculatum Palm fern Photo: CC0, author not stated Blechnum attenuatum Aspleniaceae Blechnum auratum Aspleniaceae Blechnum australe Blechnum australe Southern Deer Fern Photo: CC BY, EliasBlechnum brasiliense Blechnum brasiliense Aspleniaceae Photo: CC BY-SA, Valérie75 Blechnum capense Aspleniaceae Blechnum cartilagineum Blechnum cartilagineum Aspleniaceae Photo: CC BY-SA, Mark MarathonBlechnum chambersii Blechnum chambersii Aspleniaceae Photo: CC BY-SA, Rudolph89Blechnum chilense Blechnum chilense Aspleniaceae Photo: CC BY, Krzysztof Ziarnek, KenraizBlechnum colensoi Blechnum colensoi Aspleniaceae Photo: CC BY-SA, Rudolph89Blechnum cordatum Blechnum cordatum Aspleniaceae Photo: CC BY-SA, Len Worthington Blechnum cyatheoides Aspleniaceae all 53 ›

Names & registers

Also known as Austroblechnum durum; Lomaria dura; Lomaria rigida; Struthiopteris dura. (WCVP, RBG Kew)

IPNIPOWOWikidataWFOWikipedia

The record

Family
Aspleniaceae
Described by
(T.Moore) C.Chr.
Native to
Antipodean Is., Chatham Is., New Zealand North +1
Wild records
243 in range · 180 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
Kew's names (WCVP) kew.names answeredas of 2026-06-04Kew's entry Blechnum durum (T.Moore) C.Chr. (plant_name_id 3175277), read from Kew's names file
GBIF species record gbif.species not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
GBIF synonyms gbif.synonyms not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
GBIF common names gbif.vernacular not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredas of 2026-10-21this species has no GBIF key of its own; its records are read under GBIF's keys for the names Kew's file holds as this plant, never by a name matched; GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 362 records of GBIF's key 9305542, Austroblechnum durum (T.Moore) Gasper & V.A.O.Dittrich (Kew's file holds it as Austroblechnum durum (T.Moore) Gasper & V.A.O.Dittrich (synonym under Blechnum durum (T.Moore) C.Chr.)): the GBIF download; 1 record within 1 km of a botanic garden, herbarium or zoo left out (1 at a botanic garden or arboretum; 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 -43.50_169.375, lapse-corrected -59 m at 6.5 °C/km; read, and set aside: NASA POWER's cell is mostly sea (28% land), so no cold floor is shown
Wikidata wikidata answeredasked 2026-10-22found by Kew's IPNI identifier 17058750-1, POWO 17058750-1
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild not asked
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
Wikimedia Commons commons 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 11 datasets via GBIF.org; each carries its own licence.

Cultifolio

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