Thuathienhuensis

Hoya thuathienhuensis T.B. Tran, Rodda & Simonsson Blumea 57, 2013: 243–247 2013

Hoya thuathienhuensis Hoya thuathienhuensis is named after the province in central Vietnam where it was collected: Thừa Thiên-Huế Province. Hoya thuathienhuensis was found in a secondary, evergreen, mountainous forest, close to virgin forests, at an altitude of 800 m. It was a strong, climbing vine, rooted in a humus-rich grass cover, climbing up the tree to a height of 20 m.

In parallel with Hoya thuathienhuensis, Hoya longipedunculata V. T. Pham & Aver. Was described, this name is now synonymous with Hoya thuathienhuensis. This plant was found in Quang Nam Province, Dai Loc Distr., Dai Hong municipality, near the city of Dai Hong. It grew in the fallen dry foliage of a broadleaf evergreen forest on a rocky sandy uplifting plateau of eroded sandstone at an altitude of approximately 550 m.

Hoya thuathienhuensis is a powerful land vine with white latex sap in all parts of the plant. Cylindrical lashes are weak, 3-5 mm in diameter, up to 5-10 m in length; slightly swollen at the nodes. Internodes (4.5–) 15-25 cm, aerial roots are formed only at the points of contact of the lashes with the support. Petiole curved, 1.0-1.7 cm long, 2-3 mm in diameter, with distinct longitudinal grooves. The leaf blade is oblong-oval, 10-14 cm long, 3-4 cm wide, green above, light green below, smooth, leathery; with the main vein depressed on the upper surface, convex on the lower surface; with 6-10 pairs of secondary veins extending from the main one at an angle of 60-80 ° and connected at the edge of the leaf.

Inflorescence is positively geotropic, convex, 5-8 cm in diameter, with 17-20 (sometimes up to 40) flowers; peduncle dark green, constant, 8-15 cm long, approx. 2 mm in diameter, pubescent at a young age; pedicels cylindrical, reddish-green, 2-3 cm long, approx. 0.8 mm in diameter, smooth. The calyx is reddish-green. The corolla is bent back, fleshy, white, glossy, 14-16 mm in diameter (20-25 mm when unfolded), sometimes with a purple tint on the outside. The corolla lobes are oval-lanceolate, curved at the edges, 9-11 mm long, in general, smooth, but densely pubescent only under the crown. The crown is dull yellow, 8-10 mm in diameter.

Blossoming in May.