Hoya erythrostemma
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Hoya erythrostemma is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).
features
Hoya erythrostemma is a perennial, climbing plant with twisting shoots. The delicate shoots have scattered adhesive roots and are sub-square in cross-section (about 2 mm in diameter). The fleshy, slightly succulent leaves are stalked, the robust, bare leaf stalks are 0.3 to 2 cm long. However, the length of the leaf stalks depends on the length of the day, shading and light intensity. The leaf blades are elliptical, 8 to 9 cm long and 2.5 to 3 cm wide. The base is wedge-shaped, the apex tapering to a point. The light green leaves are bare with a distinct lighter midrib. From it go from 5 to 6 paired leaf veins at an angle of about 60 ° laterally. About 3 to 6 mm from the edge there is a leaf vein that is almost parallel to the edge and where the secondary veins end.
The umbel-shaped, mostly upright inflorescence has 28 to 34 flowers. The surface is strongly arched to hemispherical. They arise laterally from the shoots. The rigid inflorescence stalks are up to 14 mm long and glabrous. The delicate flower stalks are glabrous and 12 to 14 mm long. The wheel-shaped corolla is usually white, but can also be yellowish or light pink. It has a diameter of 1 cm and is very thickly covered with stiff hair on the inside. This gives the flower the appearance of being covered in needle-like ice crystals. The corolla lobes are triangular and pointed. The stalked corolla is mostly deep red, but varies from light red, yellowish to whitish. The stem is long at 2 mm. The tips of the secondary crown are usually very narrow, elliptical, 3 mm long and 1.75 mm wide at the base. Both the inner and outer processes are pointed. The pollinia are up to 5 mm long and winged (provided with outer membranes). The caudiculae are about 130 µm wide. The corpusculum is egg-shaped, approx. 0.2 mm wide. The scent of the flower is described as mild .
The spindle-shaped follicle measures 14 cm in length and 0.4 cm in diameter.
Similar Art
Hoya erythrostemma is Hoya elliptica Hook.f. very similar. The flowers of this species are somewhat larger and not quite as hairy as Hoya erythrostemma . The flowers of Hoya mindorensis Schltr. are smaller and the hair is darker.
Geographical distribution and habitat
The species has a relatively large range that extends from Myanmar, Thailand, Laos, Malaysia to Borneo, Java and Sumatra. The habitat are tropical rainforests
Taxonomy
The taxon Hoya erythrostemma was proposed by Arthur Francis George Kerr in 1939. Kerr (BMI 1939: 460, 1939). Hoffmann et al. (2002) name a specimen that was collected in Surat Thailand and is kept in the herbarium of Kew Gardens (Kloss 6909). This specimen was again designated as the holotype by Robert Dale Kloppenburg. Robert Dale Kloppenburg downgraded the taxon to a subspecies in 2014. Kloppenburg did not follow Plants of the World online and continues to accept Hoya erythrostemma as a valid species.
literature
- 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. 152)
- Robert Dale Kloppenburg: Malaysian Hoyas. A monograph. Fresno, 2004 Online at Biodiversity Heritage Library , p. 202
- Surisa Somadee, Jens Kühne: Hoya 200 different wax flowers. 96 p., Formosa-Verlag, Witten 2011 ISBN 978-3-934733-08-4 (p. 46/47)
- Anders Wennström, Katarina Stenman: The Genus Hoya - Species and Cultivation. 144 p., Botanova, Umeå 2008 ISBN 978-91-633-0477-4 (p. 57)
Individual evidence
- ↑ 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 Jstor , here p. 464/62.
- ↑ Robert Dale Kloppenburg: Hoya mindorensis Schlechter 1906 subsp. erythrostemma Kerr 1939. Hoya New, 2 (2): 10-11, 2014 Online at Biodiversity Heritage Library
- ↑ Kew Science - Plants of the World online: Hoya erythrostemma Kerr