Zieria obcordata subsp. wuuluman McMaster & Duretto, 2025

Zieria obcordata subsp. wuuluman McMaster & Duretto , subsp. nov.

Type: NEW SOUTH WALES. Bulbudgeree Station near Wuuluman, 15 km east-north-east of Wellington , 18 Oct 1978, J.A.Armstrong 1267 (holo: NSW368782!; iso (all n.v.): AD, HO, K, L, MEL) .

Diagnosis and description

Differs from the typical subspecies in having glandular– verrucose branchlets ( v. with or without scattered glandular tubercules) and cocci that are prominently glandular–

verrucose with large hemispherical glands ( v. smooth or slightly glandular tuberculate; Fig. 5 View Fig ).

Illustration

Armstrong (2002, p. 405, fig. 92), as Zieria obcordata .

Distribution

Known from two subpopulations on ‘Bulbudgeree’ Station near Wuuluman, east-north-east of Wellington.

Etymology

The subspecific epithet refers to Wuuluman, a local placename. Verbal permission to use the name was granted to Eilish McMaster over the telephone by the Wellington Local Aboriginal Land Council (4 July 2024).

Conservation assessment

Zieria obcordata subsp. wuuluman is highly localised and known with certainty from a single population with four subpopulations occurring in a limited area ~ 1 km across. The species has been extensively surveyed in the area through the Saving our Species program. The area is heavily disturbed, and though stock and wildlife have been excluded from some plants, these remain ongoing threats to plants and successful recruitment outside these small, protected areas. The subspecies occurs entirely on private property, in heavily disturbed areas and is therefore not secure in the long term. Shelly et al. (2021) indicated that the subspecies had significant reduction in plant numbers (an average loss of 84% of plants at selected sites) due to drought conditions between 2017 and 2019. Significant recruitment (thousands of seedlings) occurred following recent wet conditions ( Shelly et al. 2021) but the success rate of these seedlings is not known. Future threats include changes in land use, such as increased stocking or clearing and climate change. The overall population consists of ≤ 250 adult individuals. The EOO of this subspecies is 1 km 2 and the AOO is 8 km 2. The assessment below is based on adult plants.

As far as could be determined, Z. obcordata subsp. wuuluman meets the requirements to be listed as a Critically Endangered Species under the New South Wales Biodiversity Conservation Act 2016 (see also IUCN Species Survival Commission 2012; IUCN Standards and Petitions Committee 2024). Following the criteria as set out in the New South Wales Biodiversity Conservation Regulation 2017, under Clause 4.3 (Restricted geographic distribution of species and other conditions; equivalent to IUCN Standards and Petitions Committee 2024, Criterion B) the subspecies is very highly restricted (EOO is <100 km 2), the population is severely fragmented (one population with several subpopulations), continued decline can be inferred for both the number of subpopulations (many small) and the quality of the habitat as the species is growing in a rural setting on private land with limited formal protection, and herbivory is well documented.

In addition, Z. obcordata subsp. wuuluman meets the requirements to be listed as an Endangered Species under Clause 4.4 (Low numbers of mature individuals of species and other conditions; equivalent to IUCN Standards and Petitions Committee 2024, Criterion C) and Clause 4.5 (Low total numbers of mature individuals of species; equivalent to IUCN Standards and Petitions Committee 2024, Criterion D) as there are ≤ 250 adult individuals, though some subpopulations have between 50 and 250 individuals; and as a Vulnerable Species under Clause 4.5 (Low total numbers of mature individuals of species; equivalent to IUCN Standards and Petitions Committee 2024, Criterion D) and Clause 4.7 (Very highly restricted geographic distribution of species–vulnerable species; equivalent to IUCN Standards and Petitions Committee 2024, Criterion D2) as the species is known with certainty from one population with an AOO of <20 km 2. The subspecies does not appear to be eligible to be listed under Clauses 4.2 (Reduction in population size of species; equivalent to IUCN Standards and Petitions Committee 2024, Criterion A) or Clause 4.6 (Quantitative analysis of extinction probability; equivalent to IUCN Standards and Petitions Committee 2024, Criterion E).

Additional specimens examined

NEW SOUTH WALES. Central Western Slopes: Bulbudgeree Stn, ~ 16 km ENE of Wellington, 17 Sep. 1988, J.D.Briggs 2376 (CANB n.v., MEL n.v., NSW); Poggy Cottage, ~ 16 km ENE of Wellington on ‘Poggy Cottage’ (2.6 km SE along the Uungula Road from Gulgong Road), 22 Oct. 2009, P.Carmen 425, D.Taylor & C.Hook (NSW, MEL n.v.); ibid, 22 Oct. 2009, P.Carmen 429, D.Taylor & C.Hook ( NSW); Smith’s property, Bulbudgeree, near Wellington , 7.Mar. 1978, C. K.Ingram, P.Althofer, R.G.Coveny s.n. ( NSW); Wuuluman, 1947, P.M.Althofer s.n. (NSW4713); Bulbudgerie near Wuuluman [15 km east-north-east of Wellington], 7 Mar. 1978, R.G. Coveny 10060 & C. K.Ingram (BRI n.v., CANB n.v., MEL n.v., MO n.v., NBG n.v., NSW, P n.v.); Property of Poggy Cottage east of Wellington , 10 Mar. 2022, D.Shelly s.n. (NSW1078497) .