This ancient relictual species occurs in scattered disjunct localities of east-central states, mostly in the Ozark region and around the southern Appalachians. Most Appalachian trees tend to have much larger maximum size in the woods (often 5-7 dm dbh versus only 2-4 dm elsewhere) and more stump sprouting, but there are no clear differences in flowers or fruits (M. Vincent, pers. comm.). In cultivation, trees can become much larger, including the state champion at Cave Hill Cemetery in JEFF: 174 cm dbh, 18 m tall, 15 m wide (KDF 2020). The FAYE champion is in Lexington Cemetery: 90 cm dbh, 23 m tall, 13 m wide (D. Leonard, pers. comm.). Flowering is in mid-May, peaking a week or so after Robinia. As in most Caesalpinioids but unlike almost all other Faboids, Cladrastis lacks nitrogen-fixing rhizobial nodules (Graves & Van de Poll 1992). In Ky. there are two main clusters of records: (1) in the central Kentucky River Palisades; (2) in southeastern mountains or adjacent bluffs (Cumberland Rv. corridor, adjacent Rugged Eastern Hills and southern Pine Mt.). Several outlying records are unverified, including some from Gm; and there has been confusion or uncertainty about several records of apparently cultivated trees. Scattered records from n. Ky. are mostly old or uncertain (BOON, CARR, GALL, KENT, PEND). W.S. Bryant showed JC a small tree at the Boone County Cliffs Preserve in 1978, but it disappeared during the 1980s; there may be colls. from this site (APSC). There is also a coll. from CARR (KNK) in 1984: near crossing of Ellis Branch, east side of US 42 to Bedford; however, a search here in 2019 was not successful. Records from the eastern Knobs and its transitions remain somewhat uncertain: ESTI (seedling found in 2016 near mouth of Red River) and MADI (perhaps just planted). Further field work is needed to the southwest. There are well-documented small populations in the Knobs of CASE (KY, MO); and there is a coll. from BULL (NCU), but perhaps from a planted tree. A coll. from JEFF (APSC) states "naturalized in woodlands in Cherokee Park"; this is not mapped here. Little (1977) mapped Cladrastis from HART or nearby; his source is unknown and that recorded county has been erroneously mapped as TODD in some previous reports. Cladrastis is known from adjacent Tenn. along bluffs of the Red Rv. in Montgomery Co. (Ch). Plants in the loess bluffs of CARL (TROY) and FULT (MUR) have been partly relocated in 2019; Cladrastis is also well known further south along these bluffs, down to La. and Miss. (K).