Hoya bonii
| Hoya bonii | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Hoya bonii | ||||||||||||
| Costantin |
Hoya bonii is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).
features
Hoya bonii is an epihytic or lithophytic twining plant with shoots up to 5 m long . The shoots are 3 mm in diameter and have numerous brown hairs when young. Older shoots are bare. The species has a yellowish milky sap.
The thick, fleshy leaves are opposite. They each have a short stem with a length of one centimeter and a diameter of four millimeters. The leaf blades are variable, mostly short-ovate to elongated-ovate with a heart-shaped, rarely also rounded base and with a more or less obtuse to acute-angled or pointed tip of the leaf. The leaf blades are 8 to 10 cm long and 3.8 to 7 cm wide. They have sparsely short hairs on the underside that can only be seen with a magnifying glass. The top is bare. The leaf veins can be seen particularly well on the underside. There are 5 to 6 pairs of secondary leaf veins. The leaves and shoots contain a yellow milky sap.
The inflorescence arises from the leaf axils. The peduncle is persistent; H. from it new inflorescences arise again and again. At the top of the peduncle the stigmas of previous inflorescences can be seen. The inflorescence stalk is stiff, measures 4 to 5 cm in length and has a diameter or thickness of 2 mm. The umbel-shaped inflorescence has a domed top, or can be hemispherical to almost spherical, and contain 12 to 32 flowers. The inflorescences are positive geotropic, so they hang down. The flower stalks are reddish brown, glabrous and about 2 cm long. The flowers are white with a whitish-pink corolla. The flat, bell-shaped corolla has a diameter of 12 to 14 mm. The hairy sepals are pointed triangular, reddish brown like the flower stalks and fused at the base. The petals are largely fused, the tips are broadly triangular. The edges are bent over. In the side view, the edges appear wavy because the areas between the corners are wider. The corolla is densely hairy on the inside and especially on the edges. The outside is bald. The secondary crown is star-shaped, with triangular, pointed corolla lobes. The flowers begin to smell of chocolate in the evening and especially at night. They are open until around noon the following day.
Similar species
The species resembles Hoya carnosa (L. f.) R. Br. And Hoya fungii Merrill, but differs in leaf shape and hairiness.
Geographical distribution and habitat
The species occurs in Vietnam in the provinces of Hai Phong and Quang Ninh . The distribution area is limited to 150 km², but the species is quite common there. The habitat of the species are secondary, evergreen rainforests on chalky subsoil near the coast, from about sea level to 100 m above sea level. The species blooms in the range in May.
Taxonomy
The species was first described in 1884 by Julien Noël Costantin under the name Hoya bonii , which is valid today , and was only found and described again for the first time in 2017.
literature
- LV Averyanov, Van The Pham, TV Maisak, Tuan Anh Le, Van Canh Nguyen, Hoang Tuan Nguyen, Phi Tam Nguyen, Khang Sinh Nguyen, Vu Khoi Nguyen, Tien Hiep Nguyen, M. Rodda: Preliminary checklist of Hoya (Asclepiadaceae) in the flora of Cambodia, Laos and Vietnam. Turczaninowia, 20 (3): 103-147, 2017 doi : 10.14258 / turczaninowia.20.3.10
Individual evidence
- ↑ Julien Noël Costantin: Asclépiadacées . In: Flore générale de l'Indo-Chine. 4. Asclépiadacées à Amaranthacées. Pp. 1–154, Paris 1912 Online at www.biodiversitylibrary.org p. 140.