''Orbexilum stipulatum'', commonly known as largestipule leather-root or Falls-of-the-Ohio scurfpea, was a flowering plant that was endemic to Rock Island in the

Falls of the Ohio The Falls of the Ohio National Wildlife Conservation Area is a national, bi-state area on the Ohio River near Louisville, Kentucky in the United States, administered by the U.S. Army Corps of Engineers. Federal status was awarded in 1981. The fal ...

; an area of rapids and rocky limestone outcrops in Kentucky's portion of the

Ohio River The Ohio River is a long river in the United States. It is located at the boundary of the Midwestern and Southern United States, flowing southwesterly from western Pennsylvania to its mouth on the Mississippi River at the southern tip of Illino ...

. No live individuals have been found since 1881 and it is presumed to be extinct.

Overview

''Orbexilum stipulatum'' is thought to have been associated with large herbivore congregations. Rock Island in the Falls of the Ohio area was the shallowest part of the Ohio River, which historically was heavily used for the migration of

American buffalo American Buffalo may refer to: *American Buffalo (play), ''American Buffalo'' (play), a play by David Mamet *American Buffalo (film), ''American Buffalo'' (film), a 1996 film of Mamet's play directed by Michael Corrente *American Buffalo (coin), a ...

. The plant's population may have collapsed following the eradication of buffalo. If this factor alone had not extirpated ''Orbexilum stipulatum'' already, Rock Island and the associated rapids were flooded in the 1920s by the creation of US Dam 41, which sealed the fate for ''Orbexilum stipulatum'' at the Falls of the Ohio. Although all searches to rediscover ''Orbexilum stipulatum'' have thus far been unsuccessful, two other species strongly associated with buffalo that were once thought to be extinct, ''

Trifolium stoloniferum ''Trifolium stoloniferum'', the running buffalo clover, is an endangered species of perennial clover native to the eastern and midwestern United States. From 1940 to 1985 it was believed to be extinct until two populations were discovered in West ...

'' and ''

Solidago shortii ''Solidago shortii'', commonly known as Short's goldenrod, is a species of goldenrod in the family Asteraceae. The only known populations of Short's goldenrod occur around the Blue Licks Battlefield State Park area of Kentucky and Harrison-Craw ...

'', have been rediscovered on old buffalo trails and a

mineral lick A mineral lick (also known as a salt lick) is a place where animals can go to lick essential mineral nutrients from a deposit of salts and other minerals. Mineral licks can be naturally occurring or artificial (such as blocks of salt that farm ...

. ''

'' also once had a population on Rock Island. However, ''Orbexilum stipulatum'' differs in that in the 20 years it was monitored by botanists, it was never once observed to produce seed. This casts doubt as to its ability to have colonized beyond Rock Island.http://www.herbarium.unc.edu/9-10-07.pdf The Heartbreak of Psoralea

References

{{Taxonbar, from=Q7100010 stipulatum Flora of Kentucky Endemic flora of the United States Extinct flora of North America Plants described in 1840 Plant extinctions since 1500