Lowland brittle fern
Cystopteris protrusa (Weath.) Blasdell
Lowland brittle fern in all of Ohio- Kingdom
- Plantae
- Phylum
- Tracheophyta
- Class
- Polypodiopsida
- Order
- Polypodiales
- Family
- Cystopteridaceae
- Genus
- Cystopteris
Range
Where it is recorded
Season shown in 0 of Ohio's 88 counties. Explore Ohio
- No result yet (44)
- Recorded, too few records for a result (42)
- Recorded, season not shown (2)
- Season shown (0)
Counties as a table
| County | Records |
|---|---|
| Adams County | Recorded, too few records for a result |
| Allen County | Recorded, too few records for a result |
| Ashland County | No qualifying records yet |
| Ashtabula County | No qualifying records yet |
| Athens County | 33 · Recorded, season not shown |
| Auglaize County | No qualifying records yet |
| Belmont County | No qualifying records yet |
| Brown County | No qualifying records yet |
| Butler County | Recorded, too few records for a result |
| Carroll County | No qualifying records yet |
| Champaign County | No qualifying records yet |
| Clark County | Recorded, too few records for a result |
| Clermont County | Recorded, too few records for a result |
| Clinton County | Recorded, too few records for a result |
| Columbiana County | No qualifying records yet |
| Coshocton County | No qualifying records yet |
| Crawford County | Recorded, too few records for a result |
| Cuyahoga County | Recorded, too few records for a result |
| Darke County | No qualifying records yet |
| Defiance County | Recorded, too few records for a result |
| Delaware County | Recorded, too few records for a result |
| Erie County | Recorded, too few records for a result |
| Fairfield County | Recorded, too few records for a result |
| Fayette County | No qualifying records yet |
| Franklin County | Recorded, too few records for a result |
| Fulton County | No qualifying records yet |
| Gallia County | No qualifying records yet |
| Geauga County | No qualifying records yet |
| Greene County | Recorded, too few records for a result |
| Guernsey County | No qualifying records yet |
| Hamilton County | 80 · Recorded, season not shown |
| Hancock County | Recorded, too few records for a result |
| Hardin County | Recorded, too few records for a result |
| Harrison County | No qualifying records yet |
| Henry County | No qualifying records yet |
| Highland County | Recorded, too few records for a result |
| Hocking County | Recorded, too few records for a result |
| Holmes County | No qualifying records yet |
| Huron County | Recorded, too few records for a result |
| Jackson County | No qualifying records yet |
| Jefferson County | No qualifying records yet |
| Knox County | Recorded, too few records for a result |
| Lake County | No qualifying records yet |
| Lawrence County | No qualifying records yet |
| Licking County | Recorded, too few records for a result |
| Logan County | No qualifying records yet |
| Lorain County | Recorded, too few records for a result |
| Lucas County | No qualifying records yet |
| Madison County | No qualifying records yet |
| Mahoning County | No qualifying records yet |
| Marion County | Recorded, too few records for a result |
| Medina County | Recorded, too few records for a result |
| Meigs County | No qualifying records yet |
| Mercer County | Recorded, too few records for a result |
| Miami County | Recorded, too few records for a result |
| Monroe County | No qualifying records yet |
| Montgomery County | Recorded, too few records for a result |
| Morgan County | Recorded, too few records for a result |
| Morrow County | Recorded, too few records for a result |
| Muskingum County | Recorded, too few records for a result |
| Noble County | No qualifying records yet |
| Ottawa County | No qualifying records yet |
| Paulding County | No qualifying records yet |
| Perry County | No qualifying records yet |
| Pickaway County | No qualifying records yet |
| Pike County | No qualifying records yet |
| Portage County | Recorded, too few records for a result |
| Preble County | Recorded, too few records for a result |
| Putnam County | No qualifying records yet |
| Richland County | Recorded, too few records for a result |
| Ross County | No qualifying records yet |
| Sandusky County | No qualifying records yet |
| Scioto County | No qualifying records yet |
| Seneca County | No qualifying records yet |
| Shelby County | No qualifying records yet |
| Stark County | Recorded, too few records for a result |
| Summit County | Recorded, too few records for a result |
| Trumbull County | Recorded, too few records for a result |
| Tuscarawas County | Recorded, too few records for a result |
| Union County | No qualifying records yet |
| Van Wert County | No qualifying records yet |
| Vinton County | Recorded, too few records for a result |
| Warren County | Recorded, too few records for a result |
| Washington County | Recorded, too few records for a result |
| Wayne County | Recorded, too few records for a result |
| Williams County | No qualifying records yet |
| Wood County | No qualifying records yet |
| Wyandot County | Recorded, too few records for a result |
No mapped range from the range source used, the USGS Gap Analysis Project, which maps land vertebrates only.
Season
When it is recorded
In Athens County
Not enough evidence
Records per week from 33 records in 8 of the 10 years from 2016 to 2025. Shows when people recorded it, not a season or how common it is.
Show as a table
| Week | Records of lowland brittle fern | Years recorded | Records of all species |
|---|---|---|---|
| Jan 4–10 | 0 | 0 | 74 |
| Jan 11–17 | 0 | 0 | 132 |
| Jan 18–24 | 0 | 0 | 107 |
| Jan 25–31 | 0 | 0 | 219 |
| Feb 1–7 | 0 | 0 | 392 |
| Feb 8–14 | 0 | 0 | 232 |
| Feb 15–21 | 0 | 0 | 235 |
| Feb 22–28 | 0 | 0 | 361 |
| Mar 1–7 | 0 | 0 | 532 |
| Mar 8–14 | 0 | 0 | 466 |
| Mar 15–21 | 0 | 0 | 593 |
| Mar 22–28 | 0 | 0 | 950 |
| Mar 29 – Apr 4 | 1 | 1 | 1,265 |
| Apr 5–11 | 6 | 2 | 1,616 |
| Apr 12–18 | 5 | 3 | 1,804 |
| Apr 19–25 | 2 | 2 | 1,926 |
| Apr 26 – May 2 | 3 | 2 | 2,291 |
| May 3–9 | 1 | 1 | 1,407 |
| May 10–16 | 0 | 0 | 1,408 |
| May 17–23 | 1 | 1 | 2,542 |
| May 24–30 | 1 | 1 | 1,821 |
| May 31 – Jun 6 | 0 | 0 | 798 |
| Jun 7–13 | 0 | 0 | 775 |
| Jun 14–20 | 0 | 0 | 830 |
| Jun 21–27 | 0 | 0 | 700 |
| Jun 28 – Jul 4 | 0 | 0 | 549 |
| Jul 5–11 | 0 | 0 | 664 |
| Jul 12–18 | 0 | 0 | 869 |
| Jul 19–25 | 0 | 0 | 700 |
| Jul 26 – Aug 1 | 0 | 0 | 673 |
| Aug 2–8 | 0 | 0 | 613 |
| Aug 9–15 | 0 | 0 | 871 |
| Aug 16–22 | 0 | 0 | 807 |
| Aug 23–29 | 0 | 0 | 1,289 |
| Aug 30 – Sep 5 | 1 | 1 | 2,925 |
| Sep 6–12 | 0 | 0 | 2,530 |
| Sep 13–19 | 0 | 0 | 2,417 |
| Sep 20–26 | 12 | 1 | 1,530 |
| Sep 27 – Oct 3 | 0 | 0 | 1,628 |
| Oct 4–10 | 0 | 0 | 1,836 |
| Oct 11–17 | 0 | 0 | 1,920 |
| Oct 18–24 | 0 | 0 | 825 |
| Oct 25–31 | 0 | 0 | 930 |
| Nov 1–7 | 0 | 0 | 881 |
| Nov 8–14 | 0 | 0 | 846 |
| Nov 15–21 | 0 | 0 | 573 |
| Nov 22–28 | 0 | 0 | 536 |
| Nov 29 – Dec 5 | 0 | 0 | 270 |
| Dec 6–12 | 0 | 0 | 982 |
| Dec 13–19 | 0 | 0 | 158 |
| Dec 20–26 | 0 | 0 | 106 |
| Dec 27 – Jan 2 | 0 | 0 | 95 |
Reported in flower
No records here show flowers yet, so there is no flowering season to show. One needs at least 20 records from 5 different years.
Reported in fruit
No records here show fruit yet, so there is no fruiting season to show. One needs at least 20 records from 5 different years.
In Ohio
Early April to mid-September, middle week Apr 26 – May 2
Records per week from 331 records in 10 of the 10 years from 2016 to 2025. Shows when people recorded it, not how common it is. The grey bars show how many records of all species were made here each week, so you can see when recording itself was high or low; the season is not adjusted by them.
Recorded on 218 dates. Latest record: November 2025.
Show as a table
| Week | Records of lowland brittle fern | Years recorded | Records of all species |
|---|---|---|---|
| Jan 4–10 | 0 | 0 | 6,211 |
| Jan 11–17 | 0 | 0 | 5,146 |
| Jan 18–24 | 0 | 0 | 4,645 |
| Jan 25–31 | 0 | 0 | 4,698 |
| Feb 1–7 | 0 | 0 | 6,023 |
| Feb 8–14 | 0 | 0 | 5,888 |
| Feb 15–21 | 0 | 0 | 5,436 |
| Feb 22–28 | 0 | 0 | 6,846 |
| Mar 1–7 | 0 | 0 | 8,321 |
| Mar 8–14 | 1 | 1 | 10,384 |
| Mar 15–21 | 0 | 0 | 12,620 |
| Mar 22–28 | 3 | 2 | 13,949 |
| Mar 29 – Apr 4 | 11 | 6 | 19,661 |
| Apr 5–11 | 20 | 6 | 26,860 |
| Apr 12–18 | 47 | 9 | 39,925 |
| Apr 19–25 | 46 | 8 | 41,623 |
| Apr 26 – May 2 | 72 | 9 | 56,391 |
| May 3–9 | 31 | 9 | 52,952 |
| May 10–16 | 15 | 6 | 53,785 |
| May 17–23 | 12 | 6 | 57,698 |
| May 24–30 | 12 | 6 | 54,651 |
| May 31 – Jun 6 | 2 | 2 | 53,099 |
| Jun 7–13 | 5 | 4 | 53,700 |
| Jun 14–20 | 3 | 3 | 56,625 |
| Jun 21–27 | 6 | 4 | 55,361 |
| Jun 28 – Jul 4 | 2 | 2 | 58,477 |
| Jul 5–11 | 5 | 5 | 61,336 |
| Jul 12–18 | 1 | 1 | 64,722 |
| Jul 19–25 | 3 | 3 | 69,753 |
| Jul 26 – Aug 1 | 1 | 1 | 59,416 |
| Aug 2–8 | 3 | 2 | 59,712 |
| Aug 9–15 | 0 | 0 | 55,994 |
| Aug 16–22 | 1 | 1 | 54,328 |
| Aug 23–29 | 0 | 0 | 51,772 |
| Aug 30 – Sep 5 | 3 | 2 | 57,167 |
| Sep 6–12 | 0 | 0 | 59,075 |
| Sep 13–19 | 3 | 2 | 54,543 |
| Sep 20–26 | 12 | 1 | 45,860 |
| Sep 27 – Oct 3 | 2 | 2 | 43,180 |
| Oct 4–10 | 0 | 0 | 37,841 |
| Oct 11–17 | 0 | 0 | 30,824 |
| Oct 18–24 | 1 | 1 | 21,156 |
| Oct 25–31 | 2 | 1 | 19,021 |
| Nov 1–7 | 0 | 0 | 14,172 |
| Nov 8–14 | 4 | 1 | 12,621 |
| Nov 15–21 | 0 | 0 | 7,965 |
| Nov 22–28 | 0 | 0 | 8,136 |
| Nov 29 – Dec 5 | 1 | 1 | 6,083 |
| Dec 6–12 | 0 | 0 | 6,004 |
| Dec 13–19 | 0 | 0 | 5,423 |
| Dec 20–26 | 1 | 1 | 5,661 |
| Dec 27 – Jan 2 | 0 | 0 | 8,459 |
Reported in flower
No records here show flowers yet, so there is no flowering season to show. One needs at least 20 records from 5 different years.
Reported in fruit
No records here show fruit yet, so there is no fruiting season to show. One needs at least 20 records from 5 different years.
What these results show
These results show when people recorded a species, not when or where it occurs. Missing weeks and low counts do not mean absence or scarcity, and counts are not abundance. Contributed records reflect where, when and what people chose to observe.
Identification
How to identify it
Often confused with
- Mackay's Fragile Fern Cystopteris tenuisOften confused in Ohio: 10 identifications in Ohio named one where the other was meant
- blunt woodsia Woodsia obtusa40 identifications worldwide named one where the other was meant
- rattlesnake fern Botrypus virginianus27 identifications worldwide named one where the other was meant
- southern lady fern Athyrium asplenioides11 identifications worldwide named one where the other was meant
From iNaturalist’s similar-species counts, refreshed monthly: confusions in Ohio first, then worldwide. Only species with an Ohio result are listed.
Months not reported
- Jan: no record
- Feb: no record
- Mar: recorded
- Apr: recorded
- May: recorded
- Jun: recorded
- Jul: recorded
- Aug: recorded
- Sep: recorded
- Oct: recorded
- Nov: recorded
- Dec: recorded
Not reported in Ohio in January to February, 2016 to 2025.
Land cover where it is recorded
| Land cover | Its recordsAll Ohio records |
|---|---|
| Forest | 90%31% |
| Developed | 8%49% |
| Farmland | 0.5%11% |
| Open water | 0.5%3% |
| Wetland | 0.5%5% |
From 186 records placed within 100 m, beside all Ohio records placed the same way. People record where they go, so this shows where records come from, not where the species lives. Land cover: USGS Annual NLCD, 2025 (opens in a new tab)
Sources
Where these results come from
- Records from iNaturalist research-grade observations and expert-identified GBIF datasets, CC0, CC BY and CC BY-NC. Sources
- Seasons use the published method and its evidence thresholds. Methods
- See it on iNaturalist (opens in a new tab)OpenPhenology is independent and not affiliated with iNaturalist.
Records behind the Ohio result
331 records from 1 dataset.
- iNaturalist Research-grade Observations (opens in a new tab) · iNaturalist.org · 331 recordsiNaturalist contributors, iNaturalist (2026). iNaturalist Research-grade Observations. iNaturalist.org. Occurrence dataset https://doi.org/10.15468/ab3s5x accessed via GBIF.org on 2026-11-13.
To cite: the GBIF download doi:10.15468/dl.y2jkt8 (opens in a new tab).
A spreadsheet (CSV) with a link to each record, on iNaturalist or GBIF. Records whose location was hidden by the observer or the source are counted but not linked.