Hoya retusa
| Hoya retusa | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Hoya retusa |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Hoya retusa | ||||||||||||
| Dalzell |
Hoya retusa is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).
features
Hoya retusa is an epiphytic , climbing, or hanging plant. It forms round shoots with a diameter of two millimeters in cross section . Young shoots are green with purple spots, older shoots are gray and sparsely hairy in the area of the nodes ; otherwise the shoots are bare. The leaves sit in groups close to and around the nodes, the areas between the nodes (internodes) are without leaves. The leaves have stems up to 5 mm long and round in cross-section. They are greenish with purple spots and bare. The leaf blades are linearly 4.5 to 5 mm long with a width of 0.5 cm. The base tapers into the stem, the apex is inverted-heart-shaped. They are thick-fleshed and bald. Purple spots are interspersed in the pale green color. The underside has a longitudinal groove, the bracts are tiny and obtuse-triangular, the edge is ciliate.
The flowers stand together individually or in very small groups up to three flowers. Usually several single flowers are open at the same time. The flower stalk is round in cross section, 7 to 8 mm long and glabrous. The sepals are oblong-elliptical, 1.5 mm long and 1 mm wide. They are slightly pointed and slightly downy hairy on the underside. The top has a glandular design. The flower is spread out like a star and has a diameter of 1.2 to 1.5 cm. The petal lobes are triangular and tapering to a point, and up to 5 mm long. They are glossy white and velvety downy, the tips are usually bent back. The secondary crown has a diameter of 5 mm and is pink to dark purple in color. The tips of the secondary crown are oblong-egg-shaped. The outer process is broad and tapering, and ascending, the inner process is pointy and ascending. The stylus head is flat. The flowers only smell weakly. The pollinarium consists of the central corpusculum and the two lateral pollinia connected by short translator arms. The pollinia are flattened-elongated, measuring 4 mm in length and 2 mm in width. The corpusculum measures 3 mm in length and 1 mm in width.
Similar species
The species is easy to identify due to the peculiar shape of the leaves. It is related to Hoya paucifora , which also has a white corolla and a purple corolla.
Geographical distribution and habitat
Hoya retusa occurs in India (Assam) in somewhat cooler lowland forests and in Indonesia (Sulawesi).
Taxonomy
The taxon was published in 1852 by Nicol Alexander Dalzell in Volume 4 of Hooker's journal of botany and Kew Garden miscellany.
literature
- Focke Albers, Ulli Meve (Hrsg.): Succulent lexicon Volume 3 Asclepiadaceae (silk plants) . Ulmer, Stuttgart 2002, ISBN 3-8001-3982-0 (p. 158).
- Anders Wennström and Katarina Stenman: The Genus Hoya - Species and Cultivation. 144 p., Botanova, Umeå 2008 ISBN 978-91-633-0477-4 (p. 117)
- Surisa Somadee, Jens Kühne: Hoya 200 different wax flowers. 96 p., Formosa-Verlag, Witten 2011 ISBN 978-3-934733-08-4 (p. 75)
- Livia Wanntorp, Paul I. Forster: Phylogenetic relationships between Hoya and the monotypic genera Madangia, Absolmia, and Micholitzia (Apocynaceae, Mardenieae): insights from flower morphology. Annals of the Missouri Botanical Garden, 94: 36-55, 2007 online at www.biodiversitylibrary.org (p. 49).
Individual evidence
- ^ Nicol Alexander Dalzell: Contributions to the Botany of Western India. Hooker's journal of botany and Kew Garden miscellany, 4: 289-295, London 1852 Online at www.biodiversitylibrary.org , pp. 294/95.