Styloglossum aquamarinum (Schuit. & de Vogel) T.Yukawa & P.J.Cribb, Bull. Natl. Mus. Nat. Sci., Tokyo, B. 40 (2014) 147.
Type: Mendum 92680 (holo E)
- Calanthe aquamarina Schuit. & de Vogel, Malesian Orchid J. 4 (2009) 99, fig. 4.
Stem (basal part and roots not known) elongated, at least 30 by 0.3–0.4 cm, apparently monopodial, or in any case elongating and producing inflorescences over several growing seasons, glabrous, terete, covered by the leaf-sheaths, many-leaved, with c. 5–8 active leaves in the apical part. Leaves distichous, articulated with the sheath, plicate, narrowly elliptic, glabrous, underneath with 5 prominent veins, 12–18.5 by 1.1–2.6 cm; leaf sheaths obliquely tubular, 3–4 by 0.4–0.6 cm; margins transparent, finely crispate; apex acuminate, almost cuspidate. Inflorescences laterally from the stem from internodes carrying a developed leaf or from internodes just below the developed leaves, arising from the base of the internode on the side of the leaf-blade, perforating the leaf-sheath, glabrous, 5–11.5 cm long, patent to suberect, densely many-flowered, with the flowers opening simultaneously; peduncle relatively short, 1–2 cm long, enveloped in c. 5 closely overlapping scale-leaves up to 2–2.5 cm long; rachis gradually tapering towards the apex, 4–9.5 cm long. Floral bracts caducous, only very young ones present. Flowers not opening widely, secund, 0.9 cm long, glabrous. Median sepal obovate, 0.77 by 0.39 cm; apex acute. Lateral sepals obliquely broadly ovate, 0.72 by 0.42 cm; apex acute. Petals broadly elliptic, 0.64 by 0.48 cm; apex subacute. Lip entire, spurred, adnate to the column; spur 0.46 cm long, broadly cylindrical, almost straight, with rounded apex; free part obovate, 0.35 by 0.24 cm, at the base with a short bilobed callus, with subacute apex. Column short and stout, 0.34 cm long. Anther cap not seen; pollinia broadly pyriform, 0.036 cm long. Pedicel with ovary c. 0.6 cm long, terete, glabrous. Fruit ellipsoid, pedicellate, 0.9 by 0.3 cm, excluding the c. 0.4 cm long pedicel.
(after Schuiteman & de Vogel, 2009)