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Sphaeropteris excelsa; photograph (c) Stella Fish, some rights reserved (CC BY) CC BY(c) Stella Fish, some rights reserved (CC BY) · observed growing wild · 2024-03-25

Sphaeropteris excelsa (R.Br. ex Endl.) R.M.Tryon

Norfolk tree fern; Norfolk Isl. tree fern; Smooth tree fern

Cyatheaceae · Norfolk Is. · listed by its family as a fern or moss

Cited as Kew's World Checklist cites it, Sphaeropteris excelsa (R.Br. ex Endl.) R.M.Tryon: GBIF's backbone key for this page carries the name with another author, (Endl.) R.M.Tryon.

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Sphaeropteris excelsa, photograph author not stated, no rights reservedSphaeropteris excelsa, photograph author not stated, no rights reservedSphaeropteris excelsa, photograph (c) Stella Fish, some rights reserved (CC BY)Sphaeropteris excelsa, photograph (c) Stella Fish, some rights reserved (CC BY)Sphaeropteris excelsa, photograph (c) Stella Fish, some rights reserved (CC BY)Sphaeropteris excelsa, photograph (c) naturewatchwidow, some rights reserved (CC BY) 13 photographs ›
Habitat figures
Coldest month, mean nightly low
16.0°C
Aug at the habitat, not a floor; extremes not used (sea cell) CHELSA
Warmest month, mean daily high
23°C
Jan, Feb and Mar at the habitat CHELSA
Rain a year (median across the range)
1,235mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
17–44DLI
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

Sphaeropteris excelsa, synonym Cyathea brownii, commonly known as the Norfolk tree fern or smooth tree fern, is probably the largest fern species in the world. It is endemic to Norfolk Island, in the Pacific Ocean near Australia and New Zealand. It is named after the botanist Robert Brown (1773-1858).

Quoted from Wikipedia, "Sphaeropteris excelsa", CC BY-SA 4.0.

About the genus · Sphaeropteris

Sphaeropteris is a genus of tree ferns in the family Cyatheaceae. It has been treated as a subgenus within the genus Cyathea, but is accepted in the Pteridophyte Phylogeny Group classification of 2016.

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

Cultivation

Grouped as a fern or moss, listed under the family Cyatheaceae in the archetype table, and Kew describes it as “tree”.

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (896 mm of 1,235 mm) takes 8 months, March to August and November to December. Mean temperature moves 5.9 °C between the warmest and coldest month. Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: September to February and May to June.

Rain

1,235 mm in the median year at the habitat, 896 mm of it March to August and November to December. Wettest month June at 130 mm, driest month October at 71 mm. Across the grid cells of the range the year's total runs 1,181 mm to 1,497 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,235 mm, is the year's rain at the top of the page; the 1,235 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: 17 to 44 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 16, the highest 90th-percentile month 44).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low 16.0 °C in August (across the grid cells of the range 15.8 °C to 16.3 °C), the warmest month's mean daily high 23.1 °C in February (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 16.0 °C, the coldest month's mean nightly low, August, 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: 56 to 61% 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.

Group. Listed under the family Cyatheaceae in the archetype table, and Kew describes it as “tree”. 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, southern hemisphere

Habitat climate of Sphaeropteris excelsa through the yearWarmest months January, February and March, mean daily high 23 °C; coldest month August, mean nightly low 16.0 °C; 1,235 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, southern hemisphere.10°15°20°25°°C · day and nightcold quarter050100150200mm rainDLI 17–44RH 56–61%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 5 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 °C23 / 22–2323 / 23–2323 / 22–2321 / 21–2220 / 20–2019 / 19–1918 / 18–1817 / 17–1818 / 18–1819 / 19–1920 / 20–2022 / 21–22
Night °C22 / 21–2222 / 22–2221 / 21–2220 / 20–2119 / 19–1918 / 17–1817 / 16–1716 / 16–1617 / 17–1717 / 17–1819 / 18–1920 / 20–21
Rain mm83 / 78–10891 / 86–11395 / 90–115118 / 111–156119 / 113–147130 / 124–161129 / 125–148103 / 99–11394 / 92–11171 / 68–9795 / 90–112107 / 102–116
DLI44 / 43–4440 / 40–4034 / 33–3427 / 26–2721 / 20–2117 / 16–1719 / 18–1924 / 24–2532 / 31–3238 / 38–3942 / 42–4344 / 44–44
RH %61 / 60–6461 / 60–6360 / 59–6259 / 58–6157 / 57–5957 / 56–5856 / 56–5856 / 55–5758 / 57–5958 / 58–5959 / 59–6061 / 60–63

The daily extremes were read at a NASA POWER cell that is 0% 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 13.1 °C, 1st-percentile night 15.2 °C, 99th-percentile day 24.5 °C.

How this section is made
Each figure is the median across the 5 grid cells holding the 28 in-range records, 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 2380:6959 (-29.025, 167.975). 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 5 distinct grid cells holding 28 of the 28 in-range records; extremes and elevation at the typical cell 2380:6959 (its coldest month's mean nightly low nearest the median across cells, though its NASA POWER cell is only 0% land and none of the 4 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 -29.00_168.125, lapse-corrected +70 m at 6.5 °C/km. Elevation: ETOPO 2022, 71 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.
NativeNorfolk Is. · 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-29.015, 167.946 · in the densest population, 29 records (94% of those in range)
Kew's description“tree” · “wet tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 31 georeferenced records inside the native range; the climate across the range on the 28 of them placed to within 10 km; the map shows only the 20 openly licensed ones, which alone would put the marker in the same place. 16 records outside the WCVP native range not used. 3 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 31 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Sphaeropteris excelsa, photograph 1did not loadSphaeropteris excelsa, photograph 2did not loadSphaeropteris excelsa, photograph 3did not loadSphaeropteris excelsa, photograph 4did not loadSphaeropteris excelsa, photograph 5did not loadSphaeropteris excelsa, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0 (2); (c) Stella Fish, some rights reserved (CC BY) (3); (c) naturewatchwidow, some rights reserved (CC BY).

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

Alyxia gynopogon Alyxia gynopogon Apocynaceae Photo: CC BY-SA, bushmanjimCoprosma baueri Coprosma baueri Rubiaceae Photo: Public domain, StickpenHibiscus insularis Hibiscus insularis Phillip Island hibiscus Photo: CC BY, naturewatchwidowAsplenium dimorphum Asplenium dimorphum Three-in-one fern Photo: CC BY, Sue CarnahanAraucaria heterophylla Araucaria heterophylla Norfolk Island pine Photo: CC BY, naturewatchwidowRhopalostylis baueri Rhopalostylis baueri Kermadec Five Finger Photo: CC0, author not stated

Other Sphaeropteris 11 in the reference

Sphaeropteris atrox Cyatheaceae Sphaeropteris brunoniana Cyatheaceae Sphaeropteris cooperi Sphaeropteris cooperi Scaly tree fern Photo: CC BY, Kevin Faccenda Sphaeropteris felina Cyatheaceae Sphaeropteris glauca Sphaeropteris glauca Cyatheaceae Photo: CC BY, Fabian BrambachSphaeropteris intermedia Sphaeropteris intermedia Cyatheaceae Photo: CC BY, Irisa HudsonSphaeropteris lunulata Sphaeropteris lunulata Balabala Photo: CC BY, Cheng-Wei CHENSphaeropteris medullaris Sphaeropteris medullaris Black tree fern Photo: CC BY-SA, Tony WillsSphaeropteris quindiuensis Sphaeropteris quindiuensis Cyatheaceae Photo: CC BY, Dick Culbert from Gibsons, B.C., CanadaSphaeropteris robusta Sphaeropteris robusta Cyatheaceae Photo: CC BY, ian_mcallanSphaeropteris tomentosissima Sphaeropteris tomentosissima Cyatheaceae Photo: CC BY-SA, Magnus Manske

Names & registers

Also known as Alsophila australis var. excelsa; Alsophila excelsa; Cyathea brownii. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Cyatheaceae
Described by
(R.Br. ex Endl.) R.M.Tryon
Native to
Norfolk Is.
Wild records
31 in range · 20 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 2026-10-22GBIF's key 5529738 is Sphaeropteris excelsa (Endl.) R.M.Tryon; the page links Kew's Sphaeropteris excelsa (R.Br. ex Endl.) R.M.Tryon, and the name is cited as Kew cites it
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; 12 records within 1 km of a botanic garden, herbarium or zoo left out (10 at a botanic garden or arboretum, 2 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 -29.00_168.125, lapse-corrected +70 m at 6.5 °C/km; read, and set aside: NASA POWER's cell is mostly sea (0% land), so no cold floor is shown
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 12 datasets via GBIF.org; each carries its own licence.

Cultifolio

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