Ctenitis ampla (Humb. & Bonpl. ex Willd.) Ching
English names not checked: Wikidata's common names were not read for this page.
3 photographs › At a glance
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Summary
Ctenitis sloanei (commonly known as the Florida tree fern, red hair comb fern, Bermuda cave fern, or Florida lacefern) is a species of wood fern native to USA (Florida), Bermuda, Cuba, the Caribbean, Mexico, Central America, and northwestern South America. Although it does not belong to the order Cyatheales (the group that contains most tree ferns), it is still considered by some to be a type of tree fern. This would make it the only tree fern native to the continental United States (the parts of the US that exclude Hawaii, Alaska and overseas territories). A member of the genus Ctenitis, it was formerly classified under the genus Dryopteris as Dryopteris ampla. More on Wikipedia ›
Quoted from Wikipedia, "Ctenitis sloanei", 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
Grouped as a fern or moss, listed under the family Polypodiaceae in the archetype table, and Kew describes it as “perennial or rhizomatous geophyte”.
Seasons
The rain rule reads no short rainy season: 70% of the median year's rain (1,441 mm of 1,904 mm) takes 8 months, March and May to November. Mean temperature moves 2.1 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere. The habitat lies within 10° of the equator, where the shift rule does not apply, so they are not shifted for a collection elsewhere.
Rain
1,904 mm in the median year at the habitat, 1,441 mm of it March and May to November. Wettest month October at 219 mm, driest month January at 93 mm. Across the grid cells of the range the year's total runs 1,317 mm to 2,712 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,933 mm, is the year's rain at the top of the page; the 1,904 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: 28 to 35 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 22, the highest 90th-percentile month 42).
Warmth and air
Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 16.0 °C, the absolute minimum 12.8 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 29.8 °C. Monthly means: the coldest month's mean nightly low 17.5 °C in January (across the grid cells of the range 11.5 °C to 22.4 °C), the warmest month's mean daily high 26.5 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: 16.0 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).
Relative humidity at the habitat: 64 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 -968 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 family Polypodiaceae in the archetype table, and Kew describes it as “perennial or rhizomatous geophyte”. 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
Mean daily high from 25 °C in Jan, Feb and Dec to 27 °C in Aug; mean nightly low from 18 °C in Jan, Feb, Mar and Dec to 19 °C in Apr, May, Jun, Jul, Aug, Sep, Oct and Nov. The cold quarter, Dec to Feb, is the three months around the coldest month's mean nightly low, centred on the 4 months in a row that tie for it. 1,904 mm of rain in the median year (the twelve monthly medians added), the wettest month Oct. The bands show the 10th to 90th percentile across 33 habitat cells. Over 44 years at a typical spot in the range (NASA POWER) the absolute minimum was 12.8 °C and the 99th-percentile day 29.8 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.
Figures by month
| Figure | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 25 / 20–27 | 25 / 21–27 | 26 / 21–28 | 26 / 20–29 | 26 / 22–30 | 26 / 22–31 | 26 / 21–31 | 27 / 22–31 | 26 / 21–30 | 26 / 21–29 | 26 / 22–27 | 25 / 21–27 |
| Night °C | 18 / 12–22 | 18 / 12–23 | 18 / 13–23 | 19 / 14–23 | 19 / 14–24 | 19 / 13–25 | 19 / 13–25 | 19 / 13–26 | 19 / 13–25 | 19 / 13–24 | 19 / 13–23 | 18 / 12–23 |
| Rain mm | 93 / 9–165 | 109 / 11–190 | 146 / 18–235 | 139 / 63–337 | 191 / 95–317 | 190 / 59–322 | 162 / 45–262 | 172 / 55–312 | 195 / 95–377 | 219 / 135–352 | 166 / 63–327 | 122 / 40–218 |
| DLI | 30 / 24–35 | 32 / 27–37 | 34 / 28–40 | 35 / 24–41 | 31 / 23–42 | 31 / 24–40 | 33 / 26–41 | 34 / 28–40 | 33 / 28–37 | 29 / 25–34 | 28 / 23–34 | 28 / 22–33 |
| RH % | 65 / 58–70 | 64 / 58–69 | 65 / 58–70 | 65 / 58–72 | 67 / 60–73 | 67 / 63–72 | 65 / 62–72 | 65 / 62–72 | 66 / 62–72 | 67 / 61–71 | 67 / 59–71 | 66 / 59–70 |
How this section is made
Natural habitat
This species has no GBIF key of its own. Its records are GBIF's under the keys of the names Kew's World Checklist holds as this plant: 2650910 (Ctenitis ampla (Humb. & Bonpl. ex Willd.) Ching, 256 records), 7877709 (Polypodium amplum Humb. & Bonpl. ex Willd., 0 records). No name was matched to GBIF; the keys are read from Kew's synonymy. How.
How this section is made
Photographs
Photographs: Krzysztof Ziarnek, Kenraiz, CC BY-SA 4.0, via Wikimedia Commons; David J. Stang, CC BY-SA 4.0, via Wikimedia Commons.
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Eleocharis elegans Elegant spikerush Photo: CC BY, Samuel Peláez Vélez
Senna spectabilis Casia amarilla Photo: CC BY, Fabricio Carvalho da Silva
Guzmania monostachia West Indian tufted airplant Photo: CC BY, Barry Cottam
Adiantum macrophyllum Largeleaf maidenhair Photo: CC BY, Daniel Mesa
Zephyranthes rosea Cuban zephyrlily Photo: CC BY, Alan Prather
Clusia minor Clusiaceae Photo: CC BY, Neptalí Ramírez MarcialOther Ctenitis 3 in the reference
Ctenitis eatonii Dryopteridaceae Photo: CC BY-SA, 許文俊 Ctenitis sieberiana Dryopteridaceae 
Ctenitis subglandulosa Dryopteridaceae Photo: CC BY, portioid Names & registers
Also known as Ctenitis sloanei; Aspidium nemophilum; Polypodium sloanei; Ctenitis catocarpa; Ctenitis nemophila and 22 more. (WCVP, RBG Kew)
The record
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.names answeredas of 2026-06-04Kew's entry Ctenitis ampla (Humb. & Bonpl. ex Willd.) Ching (plant_name_id 3151403), read from Kew's names filegbif.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 askedgbif.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 askedgbif.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 askedwcvp.distribution answeredas of 2026-06-04gbif.occurrences answeredasked 2026-10-22this 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; 256 records of GBIF's key 2650910, Ctenitis ampla (Humb. & Bonpl. ex Willd.) Ching (Kew's file holds it as Ctenitis ampla (Humb. & Bonpl. ex Willd.) Ching (accepted)): the GBIF download; 0 records of GBIF's key 7877709, Polypodium amplum Humb. & Bonpl. ex Willd. (Kew's file holds it as Polypodium amplum Willd. (synonym under Ctenitis ampla (Humb. & Bonpl. ex Willd.) Ching)): GBIF occurrence search API; 8 records within 1 km of a botanic garden, herbarium or zoo left out (7 at a botanic garden or arboretum, 1 at a zoo; Wikidata's list)climate answeredasked 2026-10-22climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 5.00_-75.625, lapse-corrected -968 m at 6.5 °C/kmwikidata answeredasked 2026-10-22found by Kew's IPNI identifier 71834-2, POWO 71834-2wikipedia answeredasked 2026-10-22inat.taxon not askedinat.photos.wild not askedinat.photos.cultivated not askedgbif.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 askedcommons answeredasked 2026-10-22openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshotEvery 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 35 datasets via GBIF.org; each carries its own licence.