Hoya balaensis
| Hoya balaensis | ||||||||||||
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| Scientific name | ||||||||||||
| Hoya balaensis | ||||||||||||
| Kidyoo & Thaithong |
Hoya balaensis is a plant of the genus of wax flowers ( Hoya ) from the subfamily of the asclepiadoideae (Asclepiadoideae). It is endemic to the Narathiwat Province in the extreme south of Thailand .
features
Hoya balaensis is a twining -climbing, epiphytic , herbaceous plant . The shoots are slender and round in cross section; they can be very long. They are glabrous, older shoots are reddish-brown in color. The leaves sit on stems 1.8 to 2.2 cm long, the diameter of the stems is 0.4 to 0.6 cm. The leaf blades are broadly ovate to heart-shaped, the dimensions are: 7.5 to 16.7 cm in length and 5.6 to 13.2 cm in width. The base is heart-shaped to approximately heart-shaped, the apex pointed briefly (akuminate). The edges are tightly turned back. Papillae are irregularly distributed on the underside of the leaf. The leaf veins can be clearly seen. Three to five distinctive leaf veins extend from the leaf base to the apex.
The convex, umbel-shaped inflorescences contain about 10 to 49 flowers. The stems of the inflorescences are 2.5 to 4.3 cm long. The five-fold, zygomorphic flowers have a double flower envelope and are hermaphroditic . They sit on 1.7 to 2 cm long, bare flower stalks. The yellowish-green sepals are egg-shaped, 1.8 to 2 mm long and 1.5 to 1.8 mm wide with a pointed apex. Five glands alternate with the sepals. The corolla is cream to yellowish white and has a diameter of 1.4 to 1.5 cm. The inside is papillary, the outside is bare. The petals are fused about halfway ( sympetalie ). The corolla tube is 2.8 to 3 mm long. The petal lobes are ovate 4.4 to 4.7 mm long and 4.8 to 5.2 mm wide; the apex is pointed. The petal lobes are bent back when the flower is fully open. The whitish pink tips of the staminal corolla are ovate-lanceolate, 3.5 to 4 mm long and 1.5 to 1.7 mm wide. The outer extension is pointed, the inner extension ascending and pink. The Pollinia are obliquely oblong, 450 to 460 µm long and 150 to 160 µm wide. The caudiculae are comparatively short, the retinaculum (or cospusculum ) is narrowly elongated (200 to 220 µm long, 70 to 80 µm wide). Fruits and seeds have not yet been observed.
The flowers are said to smell similar to the bread flower , Vallaris glabra Kuntze. The smell of Vallaris glabra is described as slightly burnt or freshly cooked rice.
Similar species
Hoya balaensis is morphologically similar to Hoya citrina Ridl. However, the leaf shape is different; this taxon has narrow-ovate to ovate leaves. The pollinia have egg-shaped corpuscula / retinacula (length / width ratio 3: 1), while Hoya citrina has conical, somewhat shorter, but much wider corpuscula (length / width ratio 1.7: 1). The smell of the flowers of the two taxa is also different. While Hoya balaensis smells like Vallaris glabra Kuntze, Hoya citrina has an intense gardenia- like scent.
The main argument for the independence of the taxon are different haplotypes in the chloroplast DNA (cpDNA) which were determined by means of the restriction fragment length polymorphism .
Geographical distribution and habitat
The species has so far only been found in the Narathiwat province in southern Thailand , near the border with Malaysia . It grows there in moist, evergreen tropical forests, mostly on trees along river banks at around 200 m above sea level.
Taxonomy
The taxon was first described in 2007 by Manit Kidyoo (bot. Abbreviation: Kidyoo ) and Obchant Thaithong (bot. Abbreviation: Thaithong ). The type material was collected on July 21, 2004 in the Bala Forest in Narathiwat Province in southern Thailand. The holotype M. Kidyoo 303 is kept in the herbarium of the Chulalongkorn University (BCU). One isotype has been deposited in the National Herbarium Nederland ( Leiden ).
literature
- Manit Kidyoo & Obchant Thaithong: A new species of Hoya (Asclepiadaceae) from southern Thailand. Blumea 52: 327-330, 2007 doi : 10.3767 / 000651907X609052
Individual evidence
- ↑ My Nice Garden - Gardening in Malayia: Web site of Elaine ML Yim
- ↑ Kidyoo & Thaithong leave the status of this taxon open ( Hoya verticillata (Vahl) G. Don var. Citrina (Ridl.) Veldkamp (or Hoya citrina Ridl.)). Wanntorp et al. (2011) treat the taxon as a separate species.
external link
- www.pakehas-hoya.com: Hoya balaensis (pictures!)