NEW SOUTH WALES FLORA ONLINE

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Synonyms: Oligochaetochilus pedinus D.L.Jones APNI*

Description: Terrestrial herb.

Leaves sessile, 8–12 in a radical rosette, loosely imbricate, usually withered at flower opening; lamina oblong to elliptic, 10–43 mm long by 5–12 mm wide, dull green, obscurely veined; margins fringed with numerous tiny white acicular cells; apex acute.

Scape 7–20 cm tall, c 2 mm diameter, 1–6 flowered. Sterile bracts 3 or 4, closely sheathing, oblong-ovate, 10–20 mm long by 4–6 mm wide, acuminate, usually chartaceous at flower maturity. Floral bracts closely sheathing, ovate-lanceolate, 5–18 mm long by 3–5 mm wide, acuminate. Pedicels 3–15 mm long, slender, straight or slightly curved. Ovary oblong to narrowly obovoid, 4–6 mm long by 2 mm wide, green. Flowers porrect to suberect; galea transparent with light brown bands; lateral sepals similar, sometimes with chequered patterns; petals transparent with 1 or 2 light brown lines. Galea curved at the base, nearly flat medially, suddently decurved to the apex, glabrous; petal flanges large, nearly touching and closing off the base of the galea, brown; petal margins flared. Dorsal sepal 19–23 mm long including the apical point, cucullate, decurved in the distal quarter; apical point porrect to upcurved, filiform, 8–12 mm long. Lateral sepals defelxed; conjoined part wider than the galea, shallowly concave, ovate-elliptic when flattened, 8–10 mm long, 9–11 mm wide; margins flat, densely hirsute, with prominent clear trichomes to c. 1 mm long; sinus very narrow, the margins glabrous; free points filiform, 14–25 mm long, divergent, curved shallowly forwards, 8–14 mm apart at the tips. Petals asymmetrical, elliptic-lanceolate, 12–14 mm long by 4.0–4.5 mm wide, straight; dorsal margin thickened, green brown, hirsute; anterior margin glabrous; proximal flange relatively large, green or brown. Labellum highly irritable, attached by a green ligulate basal claw c. 2.3 mm long by 2 mm wide. Lamina narrowly elliptical to oblong-elliptical, 5.0–5.8 mm long by 2.5 mm wide, green to light brown; basal lobe lower than the main lamina, erect, c. 1 mm long by 2 mm wide, covered with beaded siliceous cells; adaxial surface also covered by beaded siliceous cells, proximally with a short narrow channel flanked by 2 outcurved swellings, nearly flat distally; abaxial survade with a deep narrow central channel extending from the basal lobe nearly to the apex, flanked by 2 paler thickened ridges; margins entire, covered with siliceous cells, the distal margins with numerous short acicular siliceous cells; apex obtuse. Labellum marginal setae 16–22, spreading or projected forward, the longest to 1.3 mm, each basal swelling with a long erect seta c. 4 mm long.

Flowering: October–November

Distribution and occurrence: Known only from South Burrabogie, south east of Hay in the western Riverina at around 85 m elevation.

On narrow outcrops of red-brown clay loam bordering black cracking clay, with annual grasses and forbs
NSW subdivisions: SWP

AVH map***

Pterostylis pedina was circumscribed in comparison to P. biseta from which it differed by its shorter sepal free points, much smaller flowers, elliptic to oblong-elliptic labellum with a narrow apex, and clumping habit. The protologue of P. pedina gives flower length including the apical point as 19–23 mm, and the lateral sepal filiform point length as 14–25 mm. The type specimen of Pterostylis biseta has flowers 21–28 mm long including the apical point, and free tips to the lateral sepals 7–21 mm long.