Introduced and assessed as invasive in the lower 48 states
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 1 of Ohio's 88 counties. Explore Ohio
No result yet (52)
Recorded, too few records for a result (25)
Recorded, season not shown (10)
Season shown (1)
Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files, 1:500,000. Show as a table
Counties as a table
alder buckthorn by Ohio county: records and mapped range
County
Records
Adams County
No qualifying records yet
Allen County
No qualifying records yet
Ashland County
Recorded, too few records for a result
Ashtabula County
27 · Recorded, season not shown
Athens County
Recorded, too few records for a result
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
Recorded, too few records for a result
Champaign County
No qualifying records yet
Clark County
Recorded, too few records for a result
Clermont County
No qualifying records yet
Clinton County
No qualifying records yet
Columbiana County
Recorded, too few records for a result
Coshocton County
No qualifying records yet
Crawford County
No qualifying records yet
Cuyahoga County
249 · Recorded, season not shown
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
72 · Recorded, season not shown
Greene County
Recorded, too few records for a result
Guernsey County
No qualifying records yet
Hamilton County
Recorded, too few records for a result
Hancock County
No qualifying records yet
Hardin County
No qualifying records yet
Harrison County
No qualifying records yet
Henry County
No qualifying records yet
Highland County
No qualifying records yet
Hocking County
No qualifying records yet
Holmes County
No qualifying records yet
Huron County
No qualifying records yet
Jackson County
No qualifying records yet
Jefferson County
No qualifying records yet
Knox County
No qualifying records yet
Lake County
47 · Recorded, season not shown
Lawrence County
No qualifying records yet
Licking County
Recorded, too few records for a result
Logan County
No qualifying records yet
Lorain County
50 · Recorded, season not shown
Lucas County
Recorded, too few records for a result
Madison County
No qualifying records yet
Mahoning County
24 · Recorded, season not shown
Marion County
Recorded, too few records for a result
Medina County
38 · Recorded, season not shown
Meigs County
No qualifying records yet
Mercer County
No qualifying records yet
Miami County
No qualifying records yet
Monroe County
No qualifying records yet
Montgomery County
Recorded, too few records for a result
Morgan County
No qualifying records yet
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
Recorded, too few records for a result
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
99 · Recorded, season not shown
Preble County
No qualifying records yet
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
No qualifying records yet
Seneca County
No qualifying records yet
Shelby County
No qualifying records yet
Stark County
45 · Recorded, season not shown
Summit County
203 · Season shown
Trumbull County
36 · Recorded, season not shown
Tuscarawas County
Recorded, too few records for a result
Union County
No qualifying records yet
Van Wert County
No qualifying records yet
Vinton County
No qualifying records yet
Warren County
Recorded, too few records for a result
Washington County
No qualifying records yet
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 Portage County
Early May to early August, middle week late June, and again late August to mid-November, middle week late September
Recorded in two separate seasons, each shown with its own early, middle and late weeks.
JanFebMarAprMayJunJulAugSepOctNovDec
Show over the bars
Recording in Portage County · records of all species each week, 31,804 in all
Records per week from 99 records in 9 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 alder buckthorn in Portage County each week, and records of all species
Week
Records of alder buckthorn
Years recorded
Records of all species
Jan 4–10
0
0
44
Jan 11–17
0
0
56
Jan 18–24
0
0
31
Jan 25–31
0
0
67
Feb 1–7
0
0
66
Feb 8–14
0
0
74
Feb 15–21
0
0
72
Feb 22–28
0
0
80
Mar 1–7
0
0
109
Mar 8–14
0
0
146
Mar 15–21
0
0
152
Mar 22–28
0
0
140
Mar 29 – Apr 4
0
0
277
Apr 5–11
0
0
451
Apr 12–18
0
0
648
Apr 19–25
0
0
641
Apr 26 – May 2
1
1
849
May 3–9
0
0
1,174
May 10–16
3
2
788
May 17–23
2
2
1,091
May 24–30
3
2
753
May 31 – Jun 6
6
4
782
Jun 7–13
3
2
1,242
Jun 14–20
3
2
1,568
Jun 21–27
7
5
1,383
Jun 28 – Jul 4
3
2
1,344
Jul 5–11
4
4
1,357
Jul 12–18
4
3
1,310
Jul 19–25
2
2
1,431
Jul 26 – Aug 1
2
1
1,439
Aug 2–8
5
4
1,037
Aug 9–15
2
2
1,056
Aug 16–22
1
1
1,145
Aug 23–29
3
2
911
Aug 30 – Sep 5
3
3
930
Sep 6–12
3
3
986
Sep 13–19
5
3
974
Sep 20–26
4
3
1,199
Sep 27 – Oct 3
7
5
985
Oct 4–10
2
2
516
Oct 11–17
3
2
417
Oct 18–24
1
1
435
Oct 25–31
12
4
401
Nov 1–7
1
1
278
Nov 8–14
0
0
251
Nov 15–21
2
1
228
Nov 22–28
0
0
130
Nov 29 – Dec 5
2
1
82
Dec 6–12
0
0
79
Dec 13–19
0
0
69
Dec 20–26
0
0
53
Dec 27 – Jan 2
0
0
77
Reported in flower
Only 4 records here show flowers, too few to show a flowering season. One needs at least 20 records from 5 different years.
Reported in fruit
No fruiting season shown here. The weeks are still too uncertain to show a season.
In Ohio
Early May to late October, middle week Jul 26 – Aug 1
Middle week · Jul 26 – Aug 1
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 1,297 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 756 dates. Latest record: November 2025.
Show as a table
Records of alder buckthorn in Ohio each week, and records of all species
Week
Records of alder buckthorn
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
1
1
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
1
1
13,949
Mar 29 – Apr 4
0
0
19,661
Apr 5–11
1
1
26,860
Apr 12–18
2
1
39,925
Apr 19–25
6
4
41,623
Apr 26 – May 2
18
8
56,391
May 3–9
23
6
52,952
May 10–16
42
7
53,785
May 17–23
31
7
57,698
May 24–30
41
6
54,651
May 31 – Jun 6
40
8
53,099
Jun 7–13
27
8
53,700
Jun 14–20
51
7
56,625
Jun 21–27
45
7
55,361
Jun 28 – Jul 4
64
9
58,477
Jul 5–11
87
10
61,336
Jul 12–18
90
8
64,722
Jul 19–25
68
8
69,753
Jul 26 – Aug 1
66
9
59,416
Aug 2–8
61
8
59,712
Aug 9–15
45
9
55,994
Aug 16–22
35
8
54,328
Aug 23–29
41
10
51,772
Aug 30 – Sep 5
37
8
57,167
Sep 6–12
46
8
59,075
Sep 13–19
35
7
54,543
Sep 20–26
41
10
45,860
Sep 27 – Oct 3
49
9
43,180
Oct 4–10
37
8
37,841
Oct 11–17
48
7
30,824
Oct 18–24
26
8
21,156
Oct 25–31
38
7
19,021
Nov 1–7
15
6
14,172
Nov 8–14
17
7
12,621
Nov 15–21
10
5
7,965
Nov 22–28
4
3
8,136
Nov 29 – Dec 5
2
1
6,083
Dec 6–12
1
1
6,004
Dec 13–19
2
2
5,423
Dec 20–26
0
0
5,661
Dec 27 – Jan 2
1
0
8,459
Reported in flower
No flowering season shown here. The weeks are still too uncertain to show a season.
Reported in fruit
Usually reported in fruit mid-June to mid-October, middle week Jul 26 – Aug 1.
From 290 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.
common buckthornRhamnus catharticaOften confused in Ohio: 18 identifications in Ohio named one where the other was meant
chokecherryPrunus virginiana212 identifications worldwide named one where the other was meant
Carolina buckthornFrangula caroliniana82 identifications worldwide named one where the other was meant
winterberry hollyIlex verticillata47 identifications worldwide named one where the other was meant
wild cherryPrunus avium46 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: 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, 2016 to 2025.
Land cover where it is recorded
Land cover
Its recordsAll Ohio records
Developed
45%49%
Forest
31%31%
Farmland
10%11%
Wetland
9%5%
Open water
3%3%
Grassland and shrub
1%0.9%
Barren
0.8%0.6%
From 835 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.
