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A survey covering almost all known sites and most areas of potential habitat of the rare plant Blandfordia cunninghamii (family Blandfordiaceae) in 2004 recorded over 4000 plants from 27 locations, with 80% of the plants in the upper Blue Mountains west of Sydney (lat 33° 40' S, long 150° 20' E), and the remainder as a disjunct occurrence on Mount Kembla in the Illawarra. Habitat requirements of Blandfordia cunninghamii were found to be southern aspect (SE to SW), a slope of > 30°, high rainfall (>1200 mm a year), good drainage, partial canopy cover (30-50%), and acid clayey sands with a pH of 4.5-5, at an altitude between 500 and 950 m. Using International Union for Conservation of Nature (IUCN) parameters, we consider that the number of plants (less than 10 000), their Extent of Occurrence (940 square km), Area of Occupancy (80 km2) are below the threshold for Vulnerable. There is observed decline in habitat and numbers and we conclude that there may be less than 10 locations (under IUCN definitions). This would mean that the species could be considered Vulnerable under IUCN Criteria.
A population of 700 Blandfordia cunninghamii Lindl. (family Blandfordiaceae) plants in the Blue Mountains, 100 km west of Sydney, New South Wales was monitored over a period of seven years, during which a part of the population area was burnt in a Hazard Reduction Burn (HRB). The survey measured flowering of Blandfordia cunninghamii in both the burnt and unburnt areas. In part of the unburnt area flowering (in December) was strongly correlated with previous September rainfall, but in another unburnt area there was no flowering at all over the seven years. An enhanced flowering response after fire was found in the burnt area and the diminution of this enhanced response in subsequent years was found to be logarithmic (taking into account potential rainfall effects). No recruitment of juvenile plants after fire was observed. 87% of seeds of Blandfordia cunninghamii were found to be germinable. Slow juvenile growth of Blandfordia cunninghamii in the field was measured over seven years. Seed was collected for two major seedbanks, the NSW Plantbank at the Australian Botanic Garden, Mt Annan and the Millennium Seedbank at Kew in the United Kingdom.
The small mallee Eucalyptus cunninghamii Sweet (family Myrtaceae) is restricted to the upper Blue Mountains of New South Wales with an outlier at Wanganderry Walls, 64 km south of Katoomba. It occurs in isolated clusters confined to windswept cliffs facing south and west, with average annual rainfall of at least 1300 mm, slopes of at least 200, and a narrow altitudinal range of 790–940 m. We investigated 38 occurrences, 16 in the Grose Valley north of Katoomba (including the five largest), and 21 in the Jamison Valley, south of Katoomba. We estimated there to be approximately 1560 trees, 75% in the Grose Valley and 25% in the Jamison Valley. Trees in the Grose are significantly shorter (0.8 m high), with more, but thinner trunks than those in the Jamison Valley (2.3 m high). There are about 12 short trees at the Wanganderry outlier. The Extent of Occurrence (EOO) (excluding the Wanganderry outlier) is about 200 km2. The Area of Occupation (AOO) for all 38 occurrences is 9420 m2, or less than one hectare, though despite its limited occurrence Eucalyptus cunninghamii could not be considered Vulnerable against IUCN Criteria at present. Leaf morphology measurements showed that Intramarginal Vein Ratio, Secondary Vein Angle and Oil Gland Density were approximately constant across the upper Blue Mountains. Fire history, bud development and flowering times, and pollination vectors were recorded. Leaf longevity is about 3 years. Flower buds emerge in spring (November) to early summer (December) and develop over a period of 18 months before flowering in late autumn (May). Fruits mature in spring. The time taken to reach flowering from germination and for regrowth after fire is about 5 years, but nearly 7 years to fruit maturity.
The recently described shrub Epacris browniae (family Ericaceae) an endemic Blue Mountains species, occurs on treeless, dry, rocky, Sydney Montane Heath, on Narrabeen and Hawkesbury Sandstone in the upper Blue Mountains, 100 km west of Sydney, New South Wales, (c. 33° 40' S; 150° 22' E) at altitudes above 800 m, and within the 1300 mm Average Annual Rainfall isohyet. Based on our surveys in the Blue Mountains (incorporating 46 locations), the Area of Occurrence of the species is estimated at 525 square km, within which the Area of Occupation is 25 hectares. The northern limit is Mt Wilson, southern limit, Mt Solitary, western limit appears to lie between Clarence and Narrow Neck (Katoomba) and eastern limit is Lawson Ridge.
The species grows either on flat terrain or on gentle southern or western slopes, sometimes blending into escarpment complex, on soils of moderate acidity (pH 6.5–6.8) and good drainage, associated most commonly with Banksia ericifolia and, in descending order of abundance, with Leptospermum trinervium, Allocasuarina distyla, Kunzea capitata, Allocasuarina nana and Hakea dactyloides.
Epacris browniae flowers in November and seeds ripen in March. Seeds are shiny, brown, minutely warty, about 0.6 mm long, and weigh 0.038 mg.
Epacris browniae does not resprout after fire. Average stem diameters at three sites with known single fire histories correlate strongly with likely maximum age and confirm that the species is a facultative reseeder with a potential lifespan of up to 50 years.
Despite its relatively narrow habitat and area of occupancy Epacris browniae is well conserved within National Parks in the Blue Mountains but its susceptibility to Phytophthora, an exotic pathogen in the Blue Mountains is unknown.