Hoya Heuschkeliana
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Hoya heuschkeliana is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).
features
Hoya heuschkeliana is a perennial , epiphytic plant that climbs on tree trunks with prostrate, creeping or twisting, even hanging shoots. The strongly branched shoots are green, wiry and round in cross section; they measure about 1 to 2 mm in cross section. They are attached to the ground with adhesive roots and are scattered with hair. The leaves are petiolate, the stems are 3 to 5 mm. The leaf blades are broadly ovate to elliptical, 2 to 5 cm long and 1 to 2.2 cm wide. The top is dark green, the bottom a little lighter. They are usually slightly convex. The base is round to wedge-shaped, the apex tapering to a point. They are succulent to leathery, and scattered hairy on the edges. The leaf veins are only indistinct. The vegetative parts secrete a white milky juice when injured.
The inflorescence is spherical and 2- to 7-flowered. The inflorescences arise outside the leaf axils on the underside of the shoot. The inflorescence stalks are 2 to 3 mm long and hairy scattered. The flower stalks measure 2 to 4 mm in length. The sepals are triangular and about 1.2 mm long. The corolla is flattened, spherical-urn-shaped, about 3.5 to 4 mm high and 5 to 7 mm in diameter. They are bare on the outside and fine papillae on the inside. The corolla tube is cream-colored. The petal lobes are triangular, 2.5 mm long and 2.5 mm wide at the base. They taper to a point, initially stand upright and tilt towards the center, with the exception of the pink tips, which are curved back. The edges of the tips are also slightly bent back. The secondary crown is yellowish. The tips of the secondary crown are lanceolate, 3 mm long and 1.2 mm wide. They rise at a 45 ° angle. They have a longitudinal groove on the underside and are winged basally. The ends are deeply cut and run out in 2 lobes. The outer extension is apron-shaped, the inner extension is pointed and stands upright. The inner appendages are bent inwards over the stylus head. The pollinia are rounded and rectangular, 300 µm long and 200 µm wide. A hyaline rim extends half the length (from the base). The corpusculum is rhombic, about 250 µm long and 100 µm wide. The apex ends in three points. Two wings attach to the basal part. The caudiculae are short (approx. 100 µm) and cylindrical with broad wings. The flowers are rich in nectar and give off a barely perceptible, sweet honey scent, especially in the late afternoon.
Fruits and seeds are not known.
Similar species
Hoya Heuschkeliana has an urn-shaped corolla, which is otherwise typical for the species of the genus Dischidia . The structure of the secondary crown is typical of the genus Hoya ; the taxon is therefore placed in the genus Hoya . Due to the peculiar construction of the secondary crown, it cannot be confused with any other species of the genus Hoya . In the phylogenetic analysis by Livia Wanntorp, Hoya heuschkeliana is the sister taxon of Hoya bilobata .
Geographical distribution and habitat
The range of the species is limited to small areas in the southern part of the island of Luzon , Philippines. The holotype came from the area around Lake Bulusan , whose lake level is 360 m above sea level.
Taxonomy
Hoya heuschkeliana was first described in 1989 by Robert Dale Kloppenburg. The holotype is Pancho 2175 , preserved in the Herbarium of the Institute of Biological Sciences of the University of the Philippines at Los Baños (CAHP) and the Herbarium of the University of California at Berkeley (UC). The species is named after Dexter Heuschkel, the then director of the Manila Memorial Gardens. There are currently three subspecies:
- Hoya heuschkeliana subsp. heuschkeliana
- Hoya heuschkeliana subsp. cajanoae Kloppenb. & Siar (2007).
- Hoya heuschkeliana subsp. marionii Kloppenb. & Ferreras (2014).
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 , pp. 152/53.
- 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. 122/23.
- Ulli Meve: Hoya heuschkeliana, a neo-endemic of Mt. Balusan (Philippines, Luzon), and remarks on the urceolate flower type in Asclepiadoideae. Asklepios 82: 7-10, 2001.
- Surisa Somadee, Jens Kühne: Hoya 200 different wax flowers. 96 p., Formosa-Verlag, Witten 2011 ISBN 978-3-934733-08-4 , p. 54
- Anders Wennström, Katarina Stenman: The Genus Hoya - Species and Cultivation. 144 p., Botanova, Umeå 2008 ISBN 978-91-633-0477-4 , p. 68
Individual evidence
- ↑ Livia Wanntorp: Pollinaria of Hoya (Marsdenieae, Apocynaceae): Shedding Light on Molecular Phylogenetics. Taxon, 56) (2): 465-478, 2007 online at JSTOR
- ^ Robert Dale Kloppenburg: Hoya heuschkeliana. The Hoyan 11 (1: Part 2): i-iii, 1989
- ↑ International Plant Names Index: Hoya heuschkeliana Kloppenb.