Pterostylis vernalis (D.L.Jones) G.N.Backh. APNI* Synonyms: Speculantha vernalis D.L.Jones APNI*
Description: Terrestrial herb
Rosette leaves 3–7, spreading; lamina ovate, 5–15 mm long by 4–10 mm wide, dark green; margins entire; apex acute; petioles slender, 3–12 mm long, narrowly winged, widening distally.
Flowering platns 10–20 cm tall, scape slender, wiry, 1–4 flowered. Sterile bracts 2–4 closely sheathing, ovate lanceolate 6–10 mm long by 2–3 mm wide, acuminate. Floral bracts similar to sterile bracts, sheathing the bedicel and ovary base. Pedicels 1–9 mm long. Flowers moderately spaced, facing inward, at most 3 open at a time; 8–10 mm long by 4.0–4.5 mm wide, bulbous, green proximally with a prominent white patch toward the base of the galea, dark brown to blackis distally; galea 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 by 6–9 mm wide, infalted at the base then tapered distally, boldly stribed, acute to apiculate, dorsal surface scapbrous. Lateral sepals erect, closely embracing the galea; sinus step-like at the top, the area bulbous when viewed from the side, shallowly notched medially when viewed from the front; frontal opening 3.0–3.5 mm wide; conjoined part 6.5–7.5 mm long, c. 5–6 mm wide, narrowed to c. 2.5 mm wide at the base, prominently striped; free points c. 3.5 mm long, tapered, acuminate, curved forwards, the tips just reaching the top of the galea. Petals oblong, 9–11 mm long and c. 3 mm wide, strongly falcate, white with brown stripes and markings, subactue; flange c. 1 mm across, broadly triangular, obtuse. Labellum erect, when set not visible through the sinus, straight or slightly curved forwards near the apex, white with a brown medial stripe and brown margins. Labellum lamina elliptical to obovate, 3–4 mm long by 1.5–1.7 mm wide, obtuse to truncate; basal appendage decurved, c. 0.8 mm long, broadest at the base; apex erect, trifid.
Capsules erect, narrowly obovoid, 10–13 mm long by 4–5 mm wide, on pedicels to 10 mm long.
Flowering: August to October
Distribution and occurrence: Known only in the vicinity of Nowra. Heath and short stature forest on sandstone, often in open sites and at the margins of outcrops, in fissures, and in shallow soil over rock plates, less often in moss under tall shrubs.
NSW subdivisions: SC
Threatened species: NSW BCA: Critically Endangered; Commonwealth EPBC: Critically Endangered
Pterostylis vernalis is unique among the Pterostylis parviflorus complex in flowering from the new replacement tuber while it is still attached to the old tuber, and before the rosette has been developed by the old tuber (Jones 2006). It has a papillose galea hood, which separates it from P. antennifera, P. parviflora, and P. ventricosa.
Text by Matt A.M. Renner (23 Jan 2020) based on Jones (2006).
Taxon concept: Jones DL (2006) Speculantha vernalis (Orchidaceae), a critically endangered new species from south-eastern New South Wales. The Orchadian 15: 277–281.
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.
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