Zieria obcordata A.Cunn.

Zieria obcordata A.Cunn. View in CoL in B.Field (ed.), Geogr. Mem. New South Wales 330 (1825)

Type: NEW SOUTH WALES. Macquarie River , Oct. 1822, A.Cunningham 92 (syn: lectotype, designated here: K [K000717168 image!]; isolecto:

BM [BM001015520 image!], BRI [AQ021623 image!], K [K000717167 image!], MEL [MEL62119 image!]).

Description

Spreading to prostrate aromatic shrub to 50 cm high and 100 cm wide. Branchlets terete, leaf bases not decurrent, smooth or slightly to prominently glandular–tuberculate, pubescent with simple hairs; hairs to ~ 0.5 mm long. Leaves trifoliolate; petiole 1.5–3.5 mm long, pilose, glandular tuberculate; central leaflet cuneate–obovate, 2–9 mm long, 1.5– 5 mm wide, margins glandular crenulate and slightly undulate, flat to recurved, apex rounded to obcordate; adaxial surface slightly glandular–verrucose, sometimes only near margins, hirsute; abaxial surface not glandular–verrucose on lamina, hirsute, midrib slightly raised, hirsute, glandular– verrucose, sometimes sparsely so, secondary venation obscure; lateral leaflets similar to terminal leaflets and slightly shorter to slightly longer. Inflorescence shorter than leaves, 1–3-flowered; peduncle 1–2.5(–9) mm long, not glandular tuberculate; pedicle 1–3 mm long, not glandular tuberculate; prophylls leaflike, smaller than leaves, simple or trifoliolate, to 5 mm long. Sepals 0.75–1.5 mm long and wide, deltate, slightly glandular–verrucose, hirsute abaxially. Petals valvate, 1.0–2.5(–4) mm long, very pale pink to creamy white, deciduous with fruit, adaxial surface with few hairs or glabrous, abaxial surface pilose. Disc glabrous, with four antisepalous lobes. Stamens 4, opposite sepals; filaments glabrous or with few hairs adaxially, slightly glandular–verrucose apically; anther glabrous, without an apiculum. Ovary glabrous, becoming pubescent with maturity; style glabrous, short, narrow; stigma slightly wider than style, 4-lobed. Cocci not apiculate, not glandular–verrucose though glandular or glandular– verrucose with large hemispherical glands, pubescent, 2.5– 4 mm long, 2–2.5 mm wide. Seed black, striated, 2.0– 2.5 mm long, 1.2–2.0 mm wide ( Fig. 5 View Fig ).

Distribution

A restricted species known from two small areas near Bathurst and Wellington, New South Wales, Australia. Specific geolocation details have been suppressed to protect the species.

Habitat and ecology

Grows in previously cleared areas in Eucalyptus and Callitris woodland and shrubland on granitic hillsides with a weedy understory of herbs and grasses. Brachychiton has been recorded from some populations.

Phenology

Flowers have been recorded from September to December, and March and May; fruit have been recorded from September to March.

Taxonomy and typification

Cunningham (1825) indicated that the original material of Zieria obcordata was collected from near the Macquarie River. Both populations, here recognised as subspecies, occur near the Macquarie River in the Bathurst and Wellington areas. The two subspecies are distinguished morphologically by the absence or presence of glandular tubercles on the cocci and stems. The isolectotypes at the Queensland Herbarium (BRI) and National Herbarium of Victoria (MEL) have cocci that are smooth, therefore the form from the Bathurst area is the type subspecies and the population near Wellington is newly described below as Z. obcordata subsp. wuuluman .

Armstrong (2002), when revising the genus Zieria , designated one of the syntypes of Z. obcordata lodged at Kew as the holotype without discussion. As outlined by McNiell (2014) this is not considered to be a valid approach and the type collections listed by Armstrong (2002) are syntypes. Zieria obcordata is lectotypified above against the specimen at Kew that Armstrong (2002) designated the holotype as this is still the logical specimen to use, containing the appropriate data (collector, location, date, etc.) and being in good condition.

Conservation status

Zieria obcordata is currently listed as an Endangered species in both New South Wales and Australian legislation. The species has an active conservation plan (New South Wales Department of Environment and Conservation 2007; Saving our Species Program 2020). Both subspecies have been assessed as Critically Endangered (see below under each subspecies) and the species listing requires review. Formally listing each subspecies separately would be appropriate.