Calystegia affinis (a twining plant) - endangered species listing

This Determination has been superseded by the 2012 Determination (Critically endangered species listing)

NSW Scientific Committee - final determination



The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the twining plant Calystegia affinis Endl.as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act. Listing of endangered species is provided for by Part 2 of the Act.

The Scientific Committee has found that:

1.Calystegia affinis  Endl. (family Convolvulaceae) is described by Green (1994) as: a Vine, climbing or creeping. Leaves with petiole 5-12 cm long; lamina sagittate with a broad sinus and short triangular lobe each side near base, 4-9 cm long, 3.5-7 cm broad, attenuate onto petiole, acute to slightly acuminate, mucronulate. Flower solitary; pedicel 4-13 cm long; bracts broadly ovate to suborbicular, 1.2-1.5 cm long, cordate. Sepals ovate, 5 mm long, mucronulate. Corolla shortly funnel-shaped, 2.5-3.5 cm long, scarcely lobed, pink with 5 creamy longitudinal bands. Fruit unknown..

2.Calystegia affinis  is endemic to Norfolk and Lord Howe Islands, and Green (1994) believes the Lord Howe Island species may be a separate subspecies as the flower is larger and the leaves broader than the Norfolk Island species. On Norfolk Island, the species is also considered to be threatened (M. Christian pers. comm.).

3.Calystegia affinis  was thought to be extinct on Lord Howe Island by Pickard (1983). He noted that it had only been collected twice (before 1875 and in 1936). In 1985, P.S. Green re-located the species at one site. Recent survey work (Hutton and Telford 1999, Hutton 2001, Hutton pers. comm.) has found that  C. affinis is only known from four localities on Lord Howe Island, one of which is adjacent to the settlement area in the north of the island and the others on the southern mountains. All known sites of  Calystegia affinis occur in the Permanent Park Preserve on Lord Howe Island.

4. The four known sites may contain as few as one plant each, as the species has a sprawling habit and can root at the nodes.

5. The main threats to the species are competition and invasion of habitat by introduced weeds, particularly Pennisetum clandestinum (kikuyu), Stenotaphrum secundatum (Buffalo grass) and Vicia sativaat the northern site, and Duchesnia indicaVerbena sp., Paspalum sp., Gamochaeta sp.,and Ageratina adenophora (Crofton weed) at the southern mountain sites. The species is also threatened by demographic and environmental stochasticity due to a small population size.

In view of the above the Scientific Committee is of the opinion that Calystegia affinis Endl. is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival or evolutionary development cease to operate.

Proposed Gazettal date: 01/11/02

Exhibition period: 01/11/02 - 05/12/02

References

Green, P. (1994) Convolvulaceae.Flora of Australia 49, 305-310.

Hutton, I. (2001) Surveys of rare plants on Lord Howe Island - June 2001. Report to NSW Scientific Committee.

Hutton, I. and Telford, I. (1999) Report on survey of Calystegia affinis on Lord Howe Island. Report to Lord Howe Island Board.

Pickard, J. (1983) Rare or threatened vascular plants of Lord Howe Island.Biological Conservation 27, 125-139.

About the NSW Scientific Committee

Page last updated: 25 January 2016