Hoya pachyclada

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Hoya pachyclada
Systematics
Order : Enzianartige (Gentianales)
Family : Dog poison family (Apocynaceae)
Subfamily : Silk plants (Asclepiadoideae)
Tribe : Marsdenieae
Genre : Wax flowers ( hoya )
Type : Hoya pachyclada
Scientific name
Hoya pachyclada
Kerr.

Hoya pachyclada is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).

features

Hoya pachyclada is an epiphytic, more rarely also lithophytic, creeping or climbing plant with strong, slightly succulent shoots up to 4 m long. The shoots have a diameter of 6 to 8 mm, are darkly colored when young and have light downy hairs; older shoots are bare and slightly woody. The leaves are stalked, the stems are 6 to 12 mm long. The stems are thick, concave on the top and have very small downy hairs. The leaf blades are obovate to almost rounded, 8 to 12 cm long and 5 to 10 cm wide. They are thick leathery and sparsely haired. The apex is blunt, the base wedge-shaped or rounded. The leaf nerve is clearly visible. The vegetative parts secrete a white milky juice when injured.

The umbel-shaped inflorescence contains 25 to 35 flowers. The peduncle is 1.5 to 3.5 cm long and sparsely covered with very small downy hairs. The thin flower stalks are 2 to 3 cm long and also sparsely covered with very small downy hairs. The sepals are egg-shaped and about 2 mm long. They are blunt and sparsely covered on the outside with very small downy hairs. The corolla has a diameter of 17 mm. The color varies from whitish, yellowish to purple, e.g. Sometimes even within a population. The petal lobes are egg-shaped, 7 mm long and 5 mm wide at the base. They taper to a point and are strongly bent back. The white corolla is flat, mostly reddish in the middle. The staminal corolla lobes are elliptical and about 4 mm long and imprinted in the middle. The outer extension is pointed, the inner extension long and pointed and keeled on the upper side in the middle. The stamen process is membranous, finely pointed and slightly split apically. The pollinia are very short. The corpusculum has an apical tip.

Similar species

Hoya pachyclada is closely related to Hoya diversifolia , which however has smaller leaves and flowers and more blunt corolla lobes.

Geographical distribution and habitat

The range of the species extends over Thailand, Laos, Cambodia and Vietnam. In Vietnam, Hoya pachyclada is a common plant in dry primary lowland forests, but also in secondary forests, from around 20 to 220 m above sea level. In the natural habitat, the species blooms from March to April.

Taxonomy

The taxon Hoya pachyclada was established in 1939 by Arthur Francis George Kerr . The taxon is accepted as a valid taxon by Plants of the World online . The holotype came from Thailand (Kawnken, Pu Wieng). The lectotype is in the Herbarium of the Natural History Museum. Raised in London, England (BM001014253). Isolectotypes are in the Herbarium of the Plant Varieties Protection Office in Bangkok (Thailand) (BK257734), in the Herbarium of Kew Gardens (England) (K000545616) and in the Muséum National d'Histoire Naturelle in Paris (France) (P00700508).

literature

  • Leonid Vladimirovich Averyanov, Van The Pham, Tatiana V. Maisak, Tuan Anh Le, Van Canh Nguyen, Hoang Tuan Nguyen, Phi Tam Nguyen, Khang Sinh Nguyen, Vu Khoi Nguyen, Tien Hiep Nguyen, Michele 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 , here p. 135.
  • Christiane Hoffmann, Ruurd van Donkelaar, Focke Albers: Hoya. In: Focke Albers, Ulli Meve (Hrsg.): Succulents Lexicon Volume 3 Asclepiadaceae (silk plants) . Pp. 147-160, Ulmer, Stuttgart 2002, ISBN 3-8001-3982-0 (p. 157).
  • Robert Dale Kloppenburg, Ann Wayman: The World of Hoyas - a pictorial guide. A revised version. 248 pp., Orca Publishing Company, Central Point, Oregon, 2007 ISBN 0-9630489-4-5 (pp. 194/95)
  • Surisa Somadee, Jens Kühne: Hoya 200 different wax flowers. 96 p., Formosa-Verlag, Witten 2011 ISBN 978-3-934733-08-4 (p. 70)

Individual evidence

  1. ↑ Arthur Francis George Kerr: Contributions to the Flora of Siam. Additamentum LII. Bulletin of Miscellaneous Information (Royal Botanic Gardens, Kew), 1939 (8): 456-465, London, 1939, here p. 462. JSTOR
  2. ↑ Kew Science - Plants of the World online: Hoya pachyclada Kerr

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