Pterostylis vernalis - profile

Indicative distribution


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Key:
known
predicted
The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Pterostylis vernalis
Conservation status in NSW: Critically Endangered
Commonwealth status: Critically Endangered
Gazetted date: 08 Jul 2011
Profile last updated: 17 Aug 2018

Description

Perennial terrestrial orchid with flowering stems 10-20 cm tall. The stems arise from an underground tuber.  1-2 basal leaf rosettes are produced per plant and these are usually present at flowering. 3-7 leaves, each on a stalk 3-12 mm long,  form each rosette; the leaf blades are ovate, 5-15 mm long, 4-10 mm wide, dark green; the leaf edges are straight and the leaf tips are pointed. Flower stalks slender, wiry, producing 1-4-flowers at the top, each flower borne on a thin stalk 1-9 mm long. Flowers moderately spaced, facing inwards, 1-3 open at once, 8-10 mm long, 4-4.5 mm wide, bulbous, green proximally with a prominent white patch towards the base of the hood (galea), dark brown to blackish distally; hood slightly inflated at the base, erect before curving forwards in a semi-circle; dorsal sepal slightly longer than the petals, the distal parts of the dorsal sepal and petals strongly scabrous. Dorsal sepal ovate-lanceolate when flattened, 12-15 mm long, 6-9 mm wide, inflated at the base then tapered distally, boldly striped, acute to apiculate, dorsal surface scabrous. Lateral sepals erect, closely embracing the hood; prominently striped; the tips just reaching the top of the hood. Petals oblong 9-11 mm long, approximately 3 mm wide, strongly falcate, white with brown stripes and markings. Labellum erect, not readily visible, straight or slightly curved forwards near the apex, white with a brown central stripe and brown margins. Labellum blade elliptical to obovate, 3-4 mm long, 1.5-1.7 mm wide, obtuse to truncate. Callus a raised central reddish ridge approximately 0.3 mm across. Column 4-5 mm long, curved away from the ovary, erect, green and white. Column wings approximately 1.3 mm long; inner margins adorned sparsely with short white cilia; mid-section approximately 0.6 mm long, dark green. Anther approximately 0.8 mm long, obtuse. Pollinia narrowly linear, approximately 1.3 mm long, yellow, mealy.  The fruit are erect, narrowly obovoid capsules 10-13 mm long, 4-5 mm wide, borne on stalks to 10 mm long.

Distribution

Pterostylis vernalis is only known from the Nowra area on the NSW south coast. There are five known populations located to the west and south-west of Nowra. Four are within a few kilometres of each other, and one is located approximately 18 km to the south-west. The total population is approximately 450-500 known individuals. The four northern populations may have once been considered as one population covering an area of approximately 3 kmMost known Pterostylis vernalis plants are located on land not reserved for conservation purposes. The exceptions are the southern-most population which is located in Jerrawangala National Park, and a part of one of the northern populations, which is located in Triplarina Nature Reserve.

Habitat and ecology

  • Pterostylis vernalis grows in open sites around moss gardens in shallow soil over sandstone sheets or moss gardens on heavy laterite associated soils, in heath and dry heathy forest/woodland.
  • The distribution of the plants throughout its range is naturally patchy as the species is often restricted to sections of rock shelf where there is only a thin layer of soil over the rock shelf and where these sites are subject to particular hydrological conditions.
  • Habitat generally contains moss gardens on various substrates
  • Pterostylis vernalis is distinguished from other species of Pterostylis by the emergence of the rosettes before the development of the inflorescence (Jones 2006).
  • Pterostylis vernalis is a seasonal perennial which is present above ground in the cooler months between late autumn until it sets seed in late spring. The above ground parts then wither and the plants persist as a dormant tuber underground over summer.
  • Pterostylis vernalis is the only Pterostylis species in the vicinity of Nowra that flowers in spring (Jones 2006).

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.


Threats

Recovery strategies

Activities to assist this species

IBRA Bioregion IBRA Subregion Known or predicted Geographic restrictions region
Other StateJervis Bay Territory Predicted None
Sydney BasinEttrema Known None
Sydney BasinJervis Known None