Hoya albiflora

Hoya albiflora
	Original illustration from Blume, Rumphia, vol. 4, plate 188
Systematics
Order :	Enzianartige (Gentianales)
Family :	Dog poison family (Apocynaceae)
Subfamily :	Silk plants (Asclepiadoideae)
Tribe :	Marsdenieae
Genre :	Wax flowers ( hoya )
Type :	Hoya albiflora
Scientific name
	Hoya albiflora
	( Flower ) zip. ex K.Schum.

Hoya albiflora is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).

features

Hoya albiflora is a climbing plant with shoots several meters long. Young shoots are sparsely hairy, older shoots are glabrous. They have a diameter of up to 5 mm. The internodes are up to 18 cm long. The leaves are stalked, the glabrous or sparsely hairy stalks are 1.8 to 3 cm long with a diameter of 1.4 to 3.0 mm. The leaf blades are elliptical, 10 to 18 cm long and 5 to 9 cm wide. The base is wedge-shaped, rounded or slightly heart-shaped, the apex is pointed. The rather soft, succulent leaf blades are light green, the upper side is glabrous, the underside with downy hairs. The leaf nerve protrudes on the top and bottom. There are 6 to 7 secondary ribs on either side of the midrib. The vegetative parts of the plant release a milky sap when injured.

The hanging inflorescence in the form of a loose umbel consists of about 5 to 20 flowers and is up to 7 cm long. It rises from the leaf ashes. The sparsely to densely hairy inflorescence stalks are 4 to 6 mm long and measure 2 to 3 mm in cross section. The sparsely to densely hairy flower stalks are 2.5 to 5.0 cm long and measure 1.0 to 1.6 mm in diameter, the lanceolate-egg-shaped sepals are lime green, 13 to 15 mm long, 6 to 7 mm at the base with sparse to thick hair on the outside. The white to creamy white, bell-shaped corolla has a diameter of 15 to 17 mm and a height of 8 to 10 mm. The bald petal lobes are triangular, 7 to 11 mm long, 5.5 to 12.0 mm wide at the base and curved upwards.

The white to creamy white corolla is 4 to 5 mm high and 7 to 8 mm in diameter. The apples are 3 to 4 mm long and 4.5 to 5.0 mm high. The outer extension is bent upwards and tightly rounded, the inner extension is axially shaped and bent back. The stem of the gynostegium is 4 mm long and has a diameter of 5.0 to 5.4 mm. The stamen appendages are lanceolate and cover the stylus head. The stylus head is recessed spherical and measures 1.8 to 2.0 mm in diameter. The pollinarium is 1.15 to 1.20 mm long and 1.0 to 1.1 mm wide. The pollinia are elongated, 1.15 to 1.20 mm long, 0.44 to 0.45 mm wide, with a transparent outer edge. The corpusculum is egg-shaped, 0.80 to 0.85 mm long, 0.32 to 0.50 mm wide. The caudicules are wingless, 0.35 to 0.37 mm long and 0.12 to 0.13 mm wide. Fruits and seeds not yet known.

Similar Art

According to Livia Wanntorp, the pollinaria of Hoya albiflora and Hoya australis are virtually identical in shape. However, they have slightly different dimensions. Foster and Liddle compare Hoya albiflora with Hoya magnifica . However, this species has much larger flowers with star-shaped, widened petal tips. The pollinia are even bigger.

Geographical distribution and habitat

The species occurs in the Morobe Province of Papua New Guinea in tropical mountain rainforests.

Taxonomy

The taxon was set up in 1849 by Georg Ludwig Blume as Pterostelma albiflorum . Karl Moritz Schumann transferred them to the genus Hoya R.Br. The holotype is kept in the herbarium of the Naturalis Museum of Natural History in Leiden, under the numbers L898168-96, L898168-95 and L898168-94. The Latin name albis = white, whitish and flora = blossom, flower indicates the flower color.

literature

Paul Irwin Foster, David J. Liddle: Taxonomis Studies on the genus Hoya R.Br. (Asclepiadaceae) in Papuasia. Austrobaileya, 3 (4): 627-641, 1992 JSTOR
Robert Dale Kloppenburg, Ann Wayman: The World of Hoyas - a book of pictures. A revised version. Orca Publishing Company, Central Point, Oregon 2007, ISBN 0-9630489-4-5 , pp. 46/47

Individual evidence

^ ^A ^b Carl Ludwig von Blume: Rumphia, sive Commentationes Botanicae imprimis de plantis Indiae Orientalis, tum penitus incognitis tum quae in libris Rheedi, Rumphii, Roxburghii, Wallichii, aliorum recensentur. Tomus Quartus. Amsterdam, 1849 p. 35 , plate 188 (online at Biodiversity Heritage Library)
↑ Livia Wanntorp: Pollinaria of Hoya (Marsdenieae, Apocynaceae): Shedding Light on Molecular Phylogenetics. Taxon, 56) (2): 465-478, 2007 online at JSTOR
↑ Kew Science - Plants of the World online: Hoya albiflora (flower) Zipp. ex K.Schum.

annotation

↑ Livia Wanntorp gives slightly different dimensions of the pollinarium. Pollinium 1 mm long, 0.3 mm wide, corpusculum ovoid, 0.5 mm long, 0.3 mm wide, caudiculae: 0.3 mm long, 0.1 mm wide.

[Rumphia-1] A ^b Carl Ludwig von Blume: Rumphia, sive Commentationes Botanicae imprimis de plantis Indiae Orientalis, tum penitus incognitis tum quae in libris Rheedi, Rumphii, Roxburghii, Wallichii, aliorum recensentur. Tomus Quartus. Amsterdam, 1849 p. 35 , plate 188 (online at Biodiversity Heritage Library)

[Wanntorp-3] Livia Wanntorp: Pollinaria of Hoya (Marsdenieae, Apocynaceae): Shedding Light on Molecular Phylogenetics. Taxon, 56) (2): 465-478, 2007 online at JSTOR

[POWO-albiflora-4] Kew Science - Plants of the World online: Hoya albiflora (flower) Zipp. ex K.Schum.

[2] Livia Wanntorp gives slightly different dimensions of the pollinarium. Pollinium 1 mm long, 0.3 mm wide, corpusculum ovoid, 0.5 mm long, 0.3 mm wide, caudiculae: 0.3 mm long, 0.1 mm wide.