Gastrodia kaohsiungensis T.P. Lin 高雄赤箭

Taiwania 63(4): 321-326, 2018 DOI: 10.6165/tai.2018.63.321 Holotype: Taiwan: Kaohsiung City, June 26, 2018, 210 m, Kuo-Hsiung Wang s.n. (TAI 287423). Diagnosis: Gastrodia kaohsiungensis resembles G. callosa and G sui, also found in Taiwan, in the shape and color of its flowers but it can be easily differentiated from them by the presence of orangish thickened papillae covering a large area inside the perianth tube versus the presence of smooth callosities in G. callosa and G sui. Mycoheterophytic orchid. Roots 4 or 5, slender, some longer than 10 cm, arising from apex of rootstock. Tuberoids fusiform, up to 6 cm long, 1.4 cm in diam., brownish. Flowering plants 4‒6 cm aboveground, or 10‒15 cm above rootstock; peduncle whitish, with 3 membranous sheaths, 3 mm in diam. near base; rachis < 5 mm long, 1‒4-flowered. Floral bracts membranous, triangular, dark-brownish, 5 × 3.8 mm. Pedicel and ovary 8 mm long. Flowers globose, 9‒15 mm long, 9‒ 12 mm across, only slightly opened, perianth tube ca. 2.4 cm across when dissected and spread out; sepals united for 70% of their length, succulent, outer surface fleshcolored, verrucose; free portion of perianth tube ovatetriangular, 4‒5 × 4‒4.5 mm, reddish-brown or darkbrown; lateral sepal longitudinally ridged; free portions of petals orangish, spreading, ca. 1.5 mm long, apex rounded, hirsute; inner surface of perianth tube glabrous, whitish, covered with orangish thickened papillae in a large area just below apex of lateral sepal, orangish papillae also occur in a small area just below apex of upper sepal. Lip succulent, more or less triangular, apex rounded or truncate, whitish, tinged with orangish, reddish-brown near apex, 5.5 (claw included) or 4.5 (not including claw) mm long, 4.3 mm wide near base, no ridge on upper surface, grooved along midrib underneath, with 2 short distinctive ridges near apex, light-blue between ridges; ridges orangish except for basal part (whitish), basal part rounded when viewed from lateral side; claw short, with 2 brownish rectangular calli. Column white, more or less compressed, reddish-brown along margin wings, straight, 7 × 4.2 mm, dilated in middle, with a pair of stelidia, stelidia taller than anther; column-foot short. Rostellum semi-orbicular. Stigma at a distance from anther and located near base of column. Anther cap oval, white; pollinia 2, white, each with 2 subequal partitions, granulose, usually composed of friable massulae. Capsule ellipsoid, 1.5‒2 cm long, stalk greater than 10 cm long. Flowering time: June and July. Distribution: Endemic to Taiwan. Only known from the type locality at an elevation of about 200 m.