Pterostylis
(from pteron, a wing, and stylis, a column; alluding to the broadly-winged column). SYN. Diplodium. ORD. Orchideae. A genus comprising about three dozen species of greenhouse, terrestrial orchids, with small, underground tubers; six are confined to New Zealand, and the rest are all Australian, one being also found in New Zealand and another in New Caledonia. Flowers usually green, often tinged or streaked with red or brown, large and solitary, or smaller and racemose, on short pedicels; dorsal sepal broad, erect, incurved, and very concave; petals lanceolate-falcate, curved under the dorsal sepal, and forming with it an arched, or almost hood-shaped upper lip or helmet; lateral sepals more or less united in a two-lobed lower lip, the lobes often terminating in long points; lip on a short claw at the end of the basal projection of the column; column elongated within the galea, and curved with it. Radical leaves ovate, tufted; cauline ones linear or lanceolate, or reduced to sheathing scales. The under-mentioned species, which are those best known to gardeners, thrive in leaf mould, lightened by the admixture of a little sand. Before putting in the soil, the pots should be one-third filled with broken crocks. Propagated by divisions. Except where otherwise stated, all the species here described are Australian.
P. acuminata (taper-pointed). fl. green; galea 1in. to 1 1/4in. long, usually produced into a point; lip oblong-linear, tapering to a point; scape one-flowered, 6in. to 9in. high. April. l. in a radical rosette, ovate or broadly elliptical, and five or broadly elliptical, and five or seven-nerved. h. 6in. 1827. (B. M. 3401; F. A. O., Part 5.) P. Banksii (Banks'). fl. green, solitary, 2in. to 3in. long; upper sepal arched forward, the lateral ones produced into long, slender tails; lip linear, the tip exserted. April. l. numerous, alternate, sheathing the whole stem, rising above the flower, narrow linear-lanceolate, acuminate. h. 6in. to 18in. New Zealand, 1832. (B. M. 3172.) P. Baptistii (Baptist's).* fl. green, marked with white and brown, solitary, and adorned with two bristle-like antennae. Winter. l. rosulate, basilar, petiolate, oblong-cuneate, the upper ones ascending the rachis. h. 1ft. 1877. (B. M. 6351; G. C. n. s., ix. 213.) P. curta (short-lipped). fl. green; galea erect, about 1 1/4in. long, acute, but not acuminate, the lower lip cuneate, with two broadly-lanceolate lobes; lip linear, rather longer than the column; scapes one-flowered, usually about 6in. high. October. l. in a radical rosette, usually on long petioles, ovate or broadly elliptical, five to nine-nerved, from under 1in. to 1 1/2in. long. 1829. (B. M. 3086; F. A. O., Part 5.) P. nutans (nodding). fl. green; galea nearly 1in. long, much curved near the base, and again towards the end, so as to give the flower a nodding appearance, the lower lip shortly and broadly cuneate; lip oblong-linear, obtuse, sometimes minutely ciliated; scape one-flowered, 6in. to 12in. high. September. l. in a radical rosette, petiolate, ovate or elliptical, 1/2in. to 1 1/2in. long. 1826. (B. M. 3085.)