Introduced and assessed as invasive in the lower 48 states
Ohio law lists it as an invasive plant: not native to Ohio, and causing, or likely to cause, economic, environmental or human health harm.
iNaturalist's volunteer curators list it as introduced in their Ohio checklist.
US-RIIS assesses a species as invasive when it causes, or is likely to cause, harm there, or is at least locally abundant and harmful ecologically, economically, or to health.
Season shown in 0 of Ohio's 88 counties. Explore Ohio
No result yet (38)
Recorded, too few records for a result (44)
Recorded, season not shown (6)
Season shown (0)
Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files, 1:500,000. Show as a table
Counties as a table
Japanese stiltgrass by Ohio county: records and mapped range
County
Records
Adams County
Recorded, too few records for a result
Allen County
No qualifying records yet
Ashland County
Recorded, too few records for a result
Ashtabula County
Recorded, too few records for a result
Athens County
117 · Recorded, season not shown
Auglaize County
No qualifying records yet
Belmont County
Recorded, too few records for a result
Brown County
No qualifying records yet
Butler County
Recorded, too few records for a result
Carroll County
Recorded, too few records for a result
Champaign County
No qualifying records yet
Clark County
No qualifying records yet
Clermont County
32 · Recorded, season not shown
Clinton County
Recorded, too few records for a result
Columbiana County
No qualifying records yet
Coshocton County
Recorded, too few records for a result
Crawford County
No qualifying records yet
Cuyahoga County
28 · Recorded, season not shown
Darke County
No qualifying records yet
Defiance County
No qualifying records yet
Delaware County
Recorded, too few records for a result
Erie County
No qualifying records yet
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
Recorded, too few records for a result
Geauga County
Recorded, too few records for a result
Greene County
Recorded, too few records for a result
Guernsey County
Recorded, too few records for a result
Hamilton County
91 · Recorded, season not shown
Hancock County
No qualifying records yet
Hardin County
No qualifying records yet
Harrison County
Recorded, too few records for a result
Henry County
No qualifying records yet
Highland County
Recorded, too few records for a result
Hocking County
27 · Recorded, season not shown
Holmes County
Recorded, too few records for a result
Huron County
No qualifying records yet
Jackson County
No qualifying records yet
Jefferson County
No qualifying records yet
Knox County
Recorded, too few records for a result
Lake County
Recorded, too few records for a result
Lawrence County
Recorded, too few records for a result
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
Recorded, too few records for a result
Madison County
No qualifying records yet
Mahoning County
Recorded, too few records for a result
Marion County
No qualifying records yet
Medina County
Recorded, too few records for a result
Meigs County
No qualifying records yet
Mercer County
No qualifying records yet
Miami County
No qualifying records yet
Monroe County
Recorded, too few records for a result
Montgomery County
Recorded, too few records for a result
Morgan County
No qualifying records yet
Morrow County
No qualifying records yet
Muskingum County
Recorded, too few records for a result
Noble County
Recorded, too few records for a result
Ottawa County
No qualifying records yet
Paulding County
No qualifying records yet
Perry County
No qualifying records yet
Pickaway County
Recorded, too few records for a result
Pike County
Recorded, too few records for a result
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
Recorded, too few records for a result
Sandusky County
No qualifying records yet
Scioto County
Recorded, too few records for a result
Seneca County
No qualifying records yet
Shelby County
No qualifying records yet
Stark County
Recorded, too few records for a result
Summit County
39 · Recorded, season not shown
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
No qualifying records yet
No mapped range from the range source used, the USGS Gap Analysis Project, which maps land vertebrates only.
Season
When it is recorded
In Hocking County
Not enough evidence
The weeks are still too uncertain to show a season. Based on 27 records in 7 of the 10 years from 2016 to 2025, above the minimum of 20 records from 5 different years.
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Hocking County · records of all species each week, 17,716 in all
Records per week from 27 records in 7 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
Records of Japanese stiltgrass in Hocking County each week, and records of all species
Week
Records of Japanese stiltgrass
Years recorded
Records of all species
Jan 4–10
0
0
44
Jan 11–17
0
0
28
Jan 18–24
0
0
28
Jan 25–31
0
0
39
Feb 1–7
0
0
46
Feb 8–14
0
0
31
Feb 15–21
0
0
16
Feb 22–28
0
0
50
Mar 1–7
0
0
68
Mar 8–14
0
0
95
Mar 15–21
0
0
90
Mar 22–28
0
0
164
Mar 29 – Apr 4
0
0
257
Apr 5–11
0
0
327
Apr 12–18
0
0
414
Apr 19–25
0
0
682
Apr 26 – May 2
0
0
761
May 3–9
0
0
367
May 10–16
0
0
481
May 17–23
0
0
491
May 24–30
1
1
509
May 31 – Jun 6
0
0
403
Jun 7–13
0
0
587
Jun 14–20
1
1
710
Jun 21–27
3
1
851
Jun 28 – Jul 4
0
0
559
Jul 5–11
0
0
937
Jul 12–18
1
1
581
Jul 19–25
0
0
707
Jul 26 – Aug 1
0
0
548
Aug 2–8
3
2
613
Aug 9–15
0
0
594
Aug 16–22
5
5
641
Aug 23–29
0
0
411
Aug 30 – Sep 5
0
0
459
Sep 6–12
0
0
341
Sep 13–19
4
4
547
Sep 20–26
1
1
357
Sep 27 – Oct 3
0
0
288
Oct 4–10
1
1
214
Oct 11–17
5
3
436
Oct 18–24
2
2
576
Oct 25–31
0
0
221
Nov 1–7
0
0
459
Nov 8–14
0
0
141
Nov 15–21
0
0
84
Nov 22–28
0
0
86
Nov 29 – Dec 5
0
0
102
Dec 6–12
0
0
39
Dec 13–19
0
0
44
Dec 20–26
0
0
86
Dec 27 – Jan 2
0
0
106
Reported in flower
Only 1 records here show flowers, too few to show a flowering season. One needs at least 20 records from 5 different years.
Reported in fruit
Only 6 records here show fruit, too few to show a fruiting season. One needs at least 20 records from 5 different years.
In Ohio
Late May to mid-October, middle week Aug 23–29
Middle week · Aug 23–29
This week · Nov 8–14
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Ohio · records of all species each week, 1,691,199 in all
Records per week from 662 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 419 dates. Latest record: October 2025.
Show as a table
Records of Japanese stiltgrass in Ohio each week, and records of all species
Week
Records of Japanese stiltgrass
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
1
1
5,888
Feb 15–21
0
0
5,436
Feb 22–28
0
0
6,846
Mar 1–7
1
1
8,321
Mar 8–14
0
0
10,384
Mar 15–21
0
0
12,620
Mar 22–28
0
0
13,949
Mar 29 – Apr 4
0
0
19,661
Apr 5–11
0
0
26,860
Apr 12–18
0
0
39,925
Apr 19–25
4
2
41,623
Apr 26 – May 2
3
2
56,391
May 3–9
7
3
52,952
May 10–16
3
3
53,785
May 17–23
9
6
57,698
May 24–30
8
6
54,651
May 31 – Jun 6
10
6
53,099
Jun 7–13
16
6
53,700
Jun 14–20
24
9
56,625
Jun 21–27
24
8
55,361
Jun 28 – Jul 4
17
8
58,477
Jul 5–11
25
7
61,336
Jul 12–18
20
6
64,722
Jul 19–25
34
8
69,753
Jul 26 – Aug 1
27
9
59,416
Aug 2–8
27
9
59,712
Aug 9–15
25
9
55,994
Aug 16–22
34
8
54,328
Aug 23–29
30
7
51,772
Aug 30 – Sep 5
51
10
57,167
Sep 6–12
41
7
59,075
Sep 13–19
43
8
54,543
Sep 20–26
68
7
45,860
Sep 27 – Oct 3
38
6
43,180
Oct 4–10
32
9
37,841
Oct 11–17
26
6
30,824
Oct 18–24
10
6
21,156
Oct 25–31
3
1
19,021
Nov 1–7
0
0
14,172
Nov 8–14
0
0
12,621
Nov 15–21
0
0
7,965
Nov 22–28
1
1
8,136
Nov 29 – Dec 5
0
0
6,083
Dec 6–12
0
0
6,004
Dec 13–19
0
0
5,423
Dec 20–26
0
0
5,661
Dec 27 – Jan 2
0
0
8,459
Reported in flower
Only 8 records here show flowers, too few to show a flowering season. One needs at least 20 records from 5 different years.
Reported in fruit
Usually reported in fruit early September to mid-October, middle week Sep 20–26.
From 160 records that show fruit. Not every photo of a plant in fruit is marked as fruiting, so this shows when people reported it in fruit, not when it fruits.
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
Telling it apart
From what Ohio’s records show. Only what the records support is shown.
white grassLeersia virginicaOften confused in Ohio: 10 identifications in Ohio named one where the other was meant
deertongueDichanthelium clandestinum40 identifications worldwide named one where the other was meant
small carpetgrassArthraxon hispidus29 identifications worldwide named one where the other was meant
river oatsChasmanthium latifolium17 identifications worldwide named one where the other was meant
nimblewillMuhlenbergia schreberi16 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: recorded
Mar: no record
Apr: recorded
May: recorded
Jun: recorded
Jul: recorded
Aug: recorded
Sep: recorded
Oct: recorded
Nov: recorded
Dec: no record
Not reported in Ohio in March and December to January, 2016 to 2025.
Land cover where it is recorded
Land cover
Its recordsAll Ohio records
Forest
68%31%
Developed
27%49%
Wetland
3%5%
Farmland
1%11%
Open water
1%3%
From 439 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
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.
