PlantNET Home DONATE TODAY | PlantNET Home | Search NSW Flora | Contact Us  
FloraOnline
Introduction
Plant Name Search
Index Search
Spatial Search
Identification Keys
Classification
Glossary
WeedAlert
Telopea Journal
Other Data Sources
NEW SOUTH WALES FLORA ONLINE Printable Page

Pterostylis atrans D.L.Jones
Family Orchidaceae
Common name: Dark-tip Greenhood

Pterostylis atrans D.L.Jones APNI*

Synonyms: Diplodium atrans (D.L.Jones) D.L.Jones & M.A.Clem. APNI*

Description: Terrestrial herb.

Rosette leaves 3–5, ovate-oblong, 1–3.5 cm long by 1–2 cm wide, dark green, margins entire or slightly irregular, apex obtuse; petioles 4–15 mm by 1 mm, not winged.

Flowering plants to 30 cm tall; scape slender, smooth. Cauline leaves 4 or 5, 1–3 cm by 3–5 mm, ovate-lanceolate, sheathing at the base, long-acuminate, basal 1 or 2 reduced and bract-like. Flower solitary, rarely 2, 1.4–2 cm long, translucent white, striped and suffused with green, red-brown towards the apex of the galea; galea gibbous at the base then erect before bending forwards then strongly decurved to the apex. Dorsal sepal 2.5–3.2 cm long by 8–12 mm wide,, inflated at the base then constricted and tapered to the apex, with a linear-filiform apical point 5–9 mm long. Lateral sepals erect, tightly embracing the galea; sinus protruding as a prominent platform-like bulge (a 'knee') when viewed from the side, flat, slightly notched or raised when viewed from the front; conjoined part 8–12 mm long and wide, narrowed to c. 3 mm wide at the base, white with dark green stripes and suffusions, the upper margins involute, suddenly tapered into the free points; free points 15–20 mm long, linear-clavoid, involute, erect, held high above the galea. Petals obliquely oblong-lanceolate, 1.5–2.5 cm by 4–5 mm, falcate, subactue, central part white, green in proximal half, red-brown towards the apex; flange c. 1 mm across, flat, obtuse. Labellum erect, curved forward in the distal third, the tip obscure or just protruding above the sinus in the set position; lamina oblong-elliptic, green and light brown then dark brown toward the obtuse to rounded apex.


Habitat
Photo Lachlan Copeland

Habit
Photo Lachlan Copeland

Flower
Photo Lachlan Copeland

Type
Specimen

Flowering: November–April

Distribution and occurrence: Widely distributed in southern New South Wales

Tall forests in ranges and foothills.
NSW subdivisions: ST
Other Australian states: Vic. Tas.
AVH map***

Pterostylis atrans is similar to P. obtusa but can be distinguished by the red-brown colour of the petal and dorsal sepal free tips (green in P. obtusa), the slightly clavate free lateral sepal tips (filiform in the P. obtusa), free tip to the dorsal sepal 5–9 mm long (3–6 mm long in P. obtusa). Pterostylis atrans is similar to P. decurva in the high-held lateral sepal tips, and long descending dorsal sepal tip, but can be distinguished by its smaller flowers and labellum not protruding from the flower, the tip of which sits back from the knee within the flower, and iis just visible above the sinus knee. Compare with images of P. decurva.

Text by Matt A.M. Renner (6 Dec 2019) based on Jones (1994)
Taxon concept: Jones DL (1994) New species of Orchidaceae from south-eastern Australia. Muelleria 8(2): 177–192.


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.
  Privacy | Copyright | Disclaimer | About PlantNET | Cite PlantNET