Hoya beccarii
| Hoya beccarii | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Hoya beccarii | ||||||||||||
| Rodda & Simonsson |
Hoya beccarii is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).
features
Hoya beccarii is an epiphytic , climbing plant with few branches. All parts of the plant contain a white milky sap. The shoots are thin, thread-like, 1.5 to 3 mm in diameter and 1 to 2 m long. They are bare and dark green in color, older parts turn gray-brown. Adhesive roots are formed on the nodes and also slightly below the nodes. The internodes are 6 to 20 cm long. The leaves are stalked, the petioles are 10 to 15 mm long, rarely only 4 mm. The flat, leathery leaf blades are narrowly lanceolate to elliptical. The base is pointed, the outer end is pointed. They measure 4 to 10 cm in length and 2 to 3.5 cm in width. The leaf blades are glossy green on top and a little lighter green on the underside. The leaf veins are pinnate with a slightly sunken midrib. The secondary leaf veins are barely visible. At the base of the leaf there are one or two egg-shaped, chestnut-brown glands. The petioles are 4 to 10 millimeters long and 2 to 3 millimeters in diameter.
The convex, umbel-shaped inflorescences arise outside the leaf axils. They are multi-flowered with 15 to 30 flowers, have a concave surface and a diameter of 5 to 7.5 cm. The persistent inflorescence stalks are curved downward (positive geotropic) and (2.5) 5 to 10 (15) cm long. They are round in cross-section, the diameter is 1.5 to 2 mm. The rachis is up to 2 cm long. The flowers sit on 0.4 to 3 cm long flower stalks that get longer from the center to the edge of the umbel. Three or four flowers on the periphery of the umbel have longer, curved flower stalks and are therefore conspicuous. In these flowers, the flower stalks reach a length of up to 5 centimeters. The sepals are elliptical-triangular with a rounded apex. They measure 1.5 to 2 mm in length and 1 to 1.3 mm in width. In each sepal sinus there is a flat, rounded gland with a diameter of about 250 μm. The five-fold, zygomorphic flowers are hermaphroditic and have a double flower envelope. The corolla has a diameter of 4 to 6 mm (or 7 to 9 mm with extended petals). The color varies from cream, pink to orange. The petals are fused about halfway ( sympetalie ). The triangular petal lobes are strongly bent outwards. They are 2 to 3.5 mm long and 2 to 3 mm wide, sparsely covered with downy hairs with a pointed (akuminate) and bald apex. The outside is bare and light pink in color. The secondary crown has a diameter of 3.5 to 4.5 mm and is 1.5 to 2 mm high. It's fleshy and orange or pink in color. The tips of the staminal corolla are oblong-egg-shaped and slightly keeled on the upper side. They have curved edges at the base, are 2.3 to 3 mm long and 0.7 to 1 mm wide. The inner, purple-colored process is ascending and pointed, and as high as the anthers . The outer process is round and slightly incised in the middle (bilobat). The stem of the secondary crown is hidden by the bent back tips of the secondary crown. It has a diameter of about 0.8 mm and is downy hairy. The pollinia are elongated with a round base and an obliquely cut apex. They are 190 to 240 μm long and 90 to 120 μm wide. The caudiculae are spatulate and broadly winged. The retinaculum is ovoid and measures 50–80 × 35–40 μm. The 1 mm high ovary with two carpels is egg-shaped and has a flattened apex.
The fruits are 15 cm long with a diameter of 8 mm. The elongated seeds are 5 to 6 mm long with a long head of hair.
Geographical distribution and habitat
Hoya beccarii occurs on the entire island of Borneo , the Malay Peninsula , Sumatra and Java (Indonesia).
It is an epiphytic, climbing species of tropical rainforests that often grows on trees along rivers and watercourses. It occurs on the Malay Peninsula from sea level to around 1000 meters above sea level. In Borneo it has so far only been found up to about 300 m above sea level.
Taxonomy
The taxon was published by Michele Rodda and Nadhanielle Simonsson Juhonewe in 2013. The specific epithet beccarii is named after Odoardo Beccari (1843–1920), an Italian botanist who was the first to collect a specimen of this species in Sarawak . The holotype and an isotype are kept in the herbarium of the Museum of Natural History in Florence (Italy) (Jul. 1866; O. Beccari 6536a leg.). The taxon is named after the Italian botanist Odoardo Beccari, who discovered the species in Sarawak in 1866, but did not give it a formal name.
The Plants of the World online database accepts Hoya beccarii as a valid taxon.
literature
- Anthony Lamb, Michele Rodda (with contributions by Linus Gokusing, Steven Bosuang and Sri Rahayu): A Guide to the Hoyas of Borneo. Natural History Publications (Borneo), Kota Kinabalu, 2016 ISBN 978-983-812-170-5 , pp. 44/45.
- Michele Rodda, Nadhanielle Simonsson Juhonewe: The taxonomy of Hoya micrantha and Hoya revoluta (Apocynaceae, Asclepioideae). Webbia: Journal of Plant Taxonomy and Geography, 68 (1): 7-16, 2013 doi : 10.1080 / 00837792.2013.802937