Cruciata laevipes Opiz, Crosswort
Account Summary
Introduction, rare casual, never refound and therefore locally extinct. Eurosiberian temperate.
1869; Smith, T.O.; boggy ground by an un-named lake in Colebrooke Park.
The discoverer of the only ever Fermanagh record of Crosswort described it as occurring, plentiful in boggy ground by the side of a small lake on the Colebrooke estate (More 1872). T.O. Smith is credited with 32 Fermanagh records dating between 1850 and 1880, including several rare ferns, some of which (but not this species) are supported by vouchers in BEL. Praeger looked for C. laevipes at or near the site in 1937, and failing to find it, he regarded it as extinct and an accidental introduction, possibly transported along with rhododendrons planted around the two small artificial lakes on the estate (Praeger 1939). Meikle et al. (Revised Typescript Flora) commented that the record was, "a strange occurrence in such a habitat. It may yet survive in the area, where it can scarcely be indigenous.".
The Cen Cat Fl Ir 2 reports Crosswort only in Meath (H22) and Co Down (H38). There is no mention of the old Fermanagh record, which geographically is not very distant from the other two VCs. Exceptionally, the plant has thoroughly naturalised itself in urban Downpatrick and has persisted there since the 18th century. The few remaining records are considered casual (FNEI 3). Three additional VCs with records are listed in the Cat Alien Pl Ir: the Fermanagh record, plus two near the River Bandon in W Cork (H3) and Mid Cork (H4).
Neither the current author (RSF), nor RHN (ie the two joint-VC Recorders for BSBI), have ever seen the plant in Fermanagh and it should be pointed out that a boggy or marshy lakeshore is a most unlikely habitat for the species. Typical ground for this perennial consists of ungrazed rough grassland, scrub or waste ground over deep, well-drained, neutral or calcareous soils. At the same time, it is distinctive and could hardly be mis-identified by a naturalist as observant as T.O. Smith. The current author (RSF) & RHN therefore accept it as a casual introduction, now long extinct.
References
More 1872; Praeger 1939; Meikle et al. (Revised Typescript Flora); Cen Cat Fl Ir 2; FNEI 3 ; Cat Alien Pl Ir