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Woodwardia radicans; photograph (c) Borja Fierro, some rights reserved (CC BY) CC BY(c) Borja Fierro, some rights reserved (CC BY) · observed growing wild · 2026-04-15

Woodwardia radicans (L.) Sm.

Chain fern; Rooting chain fern; European chain fern

Blechnaceae · Corse, Portugal +8 · listed by its genus as a fern or moss

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Woodwardia radicans, photograph (c) Rui Ribeiro, some rights reserved (CC BY)Woodwardia radicans, photograph (c) Rui Ribeiro, some rights reserved (CC BY)Woodwardia radicans, photograph (c) Rui Ribeiro, some rights reserved (CC BY)Woodwardia radicans, photograph (c) Rosario Douglas, some rights reserved (CC BY)Woodwardia radicans, photograph (c) Vítor Jorge, some rights reserved (CC BY)Woodwardia radicans, photograph (c) Vítor Jorge, some rights reserved (CC BY) 66 photographs ›
Habitat figures
Cold floor (1 night in 100)
4.9°C
Record low 0.6 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
22°C
Aug at the habitat CHELSA
Rain a year (median across the range)
1,370mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
10–42DLI
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
Wet winters: the rain comes October to April, read as a winter growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Woodwardia radicans, the chain fern, European chain fern or rooting chainfern, is a species of fern in the family Blechnaceae, mainly found in Macaronesia and southwestern Europe, but is also found in southern Italy and Crete. Growing to 1.8 m (6 ft) tall by 2 m (7 ft) broad, it is evergreen with arching fronds. The pinnae have curved, finely-toothed segments. The plant derives its common name from the linked sori on the undersides of the fronds.

Quoted from Wikipedia, "Woodwardia radicans", CC BY-SA 4.0.

About the genus · Woodwardia

Woodwardia is a genus of ferns in the family Blechnaceae, in the suborder Aspleniineae of the order Polypodiales. Species are known as netted-chain ferns. The genus is native to warm temperate and subtropical regions of the Northern Hemisphere. More on Wikipedia ›

Quoted from Wikipedia, "Woodwardia", CC BY-SA 4.0.

Cultivation

Grouped as a fern or moss, listed under the genus Woodwardia in the archetype table, and Kew describes it as “perennial”.

Seasons

The rain rule reads a winter growing season: 70% of the median year's rain (987 mm of 1,353 mm) falls in October to April, cooler than the year (wet-season mean 12.2 °C against a yearly mean of 14.6 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to October.

Rain

1,353 mm in the median year at the habitat, 987 mm of it October to April. Wettest month December at 174 mm, driest month July at 44 mm. Across the grid cells of the range the year's total runs 808 mm to 1,968 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,370 mm, is the year's rain at the top of the page; the 1,353 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: 10 to 42 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 8, the highest 90th-percentile month 47).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 4.9 °C, the absolute minimum 0.6 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 31.6 °C. Monthly means: the coldest month's mean nightly low 8.3 °C in February (across the grid cells of the range 3.7 °C to 13.7 °C), the warmest month's mean daily high 21.9 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: 4.9 °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: 62 to 67% 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 +92 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.

Group. Listed under the genus Woodwardia in the archetype table, and Kew describes it as “perennial”. A group is taken only where Kew's description of the species agrees with the table's listing. The table gives no figure and no prose; the cold floor is the habitat's alone.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Woodwardia radicans through the yearWarmest month August, mean daily high 22 °C; coldest month February, mean nightly low 8.3 °C; 1,353 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.-10°0°10°20°30°40°frost31.6° 99th-percentile day, NASA POWER0.6° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200250300mm rainDLI 10–42RH 62–67%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 297 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 °C12 / 10–1612 / 10–1614 / 12–1614 / 13–1616 / 15–1819 / 18–2121 / 20–2322 / 21–2321 / 20–2218 / 17–2015 / 13–1813 / 10–17
Night °C9 / 4–148 / 4–149 / 5–1410 / 6–1412 / 9–1615 / 12–1817 / 14–2018 / 15–2117 / 13–2114 / 10–1912 / 7–179 / 5–15
Rain mm139 / 89–224124 / 88–198124 / 75–181117 / 70–17497 / 49–13467 / 27–8444 / 13–6758 / 22–85100 / 60–130146 / 100–224163 / 115–243174 / 124–280
DLI11 / 10–1717 / 15–2325 / 24–3133 / 30–3838 / 35–4341 / 38–4642 / 37–4738 / 33–4329 / 27–3519 / 17–2613 / 11–1910 / 8–16
RH %63 / 61–6963 / 61–6862 / 60–6863 / 62–6965 / 62–7066 / 61–7167 / 59–7166 / 60–7165 / 62–7064 / 61–6963 / 61–6864 / 61–69
How this section is made
Each figure is the median across the 297 grid cells on land that hold in-range records (1408 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 1091:4077 (35.425, 23.875). Over 44 years there: absolute minimum 0.6 °C, 1st-percentile night 4.9 °C, 99th-percentile day 31.6 °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 297 distinct grid cells holding 1408 of the 1419 in-range records (11 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1091:4077 (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 35.50_23.750, lapse-corrected +92 m at 6.5 °C/km. Elevation: ETOPO 2022, 327 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.
NativeCorse, Portugal, Spain, Italy, Kriti, Sicilia, Algeria, Azores, Canary Is., Madeira · introduced: Great Britain, Ireland, France, California, Florida · 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 marker38.56, -28.362 · in the densest population, 485 records (31% of those in range)
Kew's description“perennial” · “subtropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 1540 georeferenced records inside the native range; the climate across the range on the 1408 of them in the land cells it reads, of 1419 placed to within 10 km; the map shows only the 1034 openly licensed ones, which alone would put the marker 1 km away. 50 records outside the WCVP native range not used. 121 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 of the 1540 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Woodwardia radicans, photograph 1did not loadWoodwardia radicans, photograph 2did not loadWoodwardia radicans, photograph 3did not loadWoodwardia radicans, photograph 4did not loadWoodwardia radicans, photograph 5did not loadWoodwardia radicans, photograph 6did not load

Photographs: (c) Rui Ribeiro, some rights reserved (CC BY) (3); (c) Rosario Douglas, some rights reserved (CC BY); (c) Vítor Jorge, some rights reserved (CC BY) (2).

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

Armeria pubigera Armeria pubigera Plumbaginaceae Photo: CC BY, Peter AbrahamsenAngelica pachycarpa Angelica pachycarpa Portuguese Angelica Photo: CC BY, Michael Berardozzi Scilla merinoi Asparagaceae Romulea clusiana Romulea clusiana Iridaceae Photo: CC BY, Darío Estraviz LópezDavallia canariensis Davallia canariensis Hare's-foot Fern Photo: CC BY, Cesar OrmazabalSaxifraga maderensis Saxifraga maderensis Madeira Saxifrage Photo: CC0, author not stated

Other Woodwardia 7 in the reference

Woodwardia areolata Woodwardia areolata Aspleniaceae Photo: CC BY-SA, ChoessWoodwardia fimbriata Woodwardia fimbriata Giant chain fern Photo: CC0, author not statedWoodwardia japonica Woodwardia japonica Asian chain fern Photo: CC0, author not statedWoodwardia orientalis Woodwardia orientalis Oriental chain fern Photo: CC BY-SA, harum.kohWoodwardia prolifera Woodwardia prolifera Blechnaceae Photo: CC BY, Cheng-Te HsuWoodwardia unigemmata Woodwardia unigemmata Jewelled chain fern Photo: CC BY, 如此甚好Woodwardia virginica Woodwardia virginica Aspleniaceae Photo: Public domain, Robert H. Mohlenbrock.

Names & registers

Also known as Blechnum houttuynii; Blechnum radicans; Blechnum stans; Woodwardia stans. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Blechnaceae
Described by
(L.) Sm.
Native to
Corse, Portugal, Spain +7
Wild records
1540 in range · 1034 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 answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 55 records within 1 km of a botanic garden, herbarium or zoo left out (50 at a botanic garden or arboretum, 1 at a herbarium, 4 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 35.50_23.750, lapse-corrected +92 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
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 75 datasets via GBIF.org; each carries its own licence.

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