Boronia inflexa subsp. torringtonensis (Rutaceae) is a shrub to 1.5 m tall. Branchlets not glandular tuberculate, hispidulous between leaf decurrencies, hairs 0.25(–0.5) mm long. Leaves imparipinnate, 3(–5)-foliolate, entire leaf in outline (9–)16–25 mm long, (8–)17–30 mm wide, glabrous or glabrescent; petiole 4–9 mm long; rachis segments 4–5 mm long; terminal leaflets (4–)10–16 mm long, (0.75–)11.25 mm wide; lateral leaflets similar to terminal leaflets. Inflorescence 3-flowered, shorter than leaves; peduncles (2.5–)4–5 mm long; prophylls 1–2.5 mm long, glabrous; anthopodia 2–3 mm long. Sepals pink, deltate, 1.5–3 mm long, 1–1.5 mm wide, glabrous, tip acuminate due to involute margins. Petals white, 4.5–6 mm long, glabrous or minutely ciliate. Anther apicula with a few simple hairs. Style glabrescent to pilose. Cocci c. 3.5 mm long, c. 2 mm wide, glabrous. Seed c. 3 mm long, c. 1.5 mm wide. It is distinguishable from the type subspecies by the larger petals (4.5–6 mm long; cf. 2.5–3.5 mm long) and from B. inflexa subsp. grandiflora by the glabrous or glabrescent leaves (cf. minutely pilose).
Boronia inflexa subsp. torringtonensis |
Boronia inflexa subsp. torringtonensis
Status: Critically Endangered on the EPBC Act list
Government evidence of impact of climate change:
Close all
-
Australian Government, Conservation Advice, Boronia inflexa subsp. torringtonensis
Changes in Climate and Drought Adapt NSW (2019) suggests that for New England and North west areas (which contains the distribution of this taxon) Hots days are projected to increase across the region by an average of 24 days per year by 2070. while autumn rainfall may marginally increase and winter rainfall decrease over the same time .
This taxon is eligible because i) it has a very highly restricted geographical range with an Area of Occupancy of 20 km2 and an Extent of Occurrence of 57 km2 ii) it occurs in a single threat defined location (the whole population of the subspecies could be adversely affected by a single drought event) iii) there is continuing decline in the quality of habitat due to grazing; human disturbance; inappropriate fire regimes and drought and iv) it has a very small population of 50 mature individuals.
Inappropriate fire regimes Frequent fires can lead to population declines in taxa where juvenile plants have not had time to mature and replenish soil seed banks in the interval between fire episodes; and in taxa where individuals are small at maturation and have low seed output until they increase in size (e.g.
However; it is likely that the overall fire frequency is much higher due to the occurrence of many small fires that are undetected; do not require suppression activities or are prescribed burns within grazing license areas. (NPWS 2003).
The species is at risk of large declines due to combined fire and drought events that affect the entire population through death of adult plants and high mortality of re establishing seedlings.
Physical damage to the habitat and individuals of the threatened species must be avoided during and after fire operations.
The main threats to Boronia inflexa subsp. torringtonensis are browsing; human disturbance; inappropriate fire regimes and drought.
A national prioritisation of the impact of the 2019 2020 bushfire season on plant species ranked Boronia inflexa subsp. torringtonensis as at high risk from high fire frequency and severity and from the cumulative risks of potential future fires (Gallagher 2020).
High frequency fire resulting in the disruption of life cycle processes in plants and animals and loss of vegetation structure and composition is listed in the Act as a Key Threatening Process.
This taxon is eligible because i) it has a very highly restricted geographical range with an Area of Occupancy of 20 km2 and an Extent of Occurrence of 57 km2 ii) it occurs in a single threat defined location (the whole population of the subspecies could be adversely affected by a single drought event) iii) there is continuing decline in the quality of habitat due to grazing; human disturbance; inappropriate fire regimes and drought and iv) it has a very small population of 50 mature individuals.
The species is at risk of large declines due to combined fire and drought events that affect the entire population through death of adult plants and high mortality of re establishing seedlings.
Populations of shrubs that grow in shallow sandy soil in the area are particularly susceptible to drought; and it is likely that Boronia inflexa subsp. torringtonensis will be affected by changes in drought frequency (L Copeland; pers. comm.
Download