Hoya narcissiflora
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Hoya narcissiflora is a plant of the genus of wax flowers ( Hoya ) of the subfamily of asclepiadoideae (Asclepiadoideae).
features
Hoya narcissiformis is a shrub-like, later epiphytic , tree-climbing plant, also hanging from branches. The shoots are thin, about 2 to 2.5 mm in diameter; they lignify with age. The internodes are very different in length, between 0.5 and 10 cm. Fresh shoots are green, older shoots are gray-green. The leaves are stalked, the stems are 0.5 to 1 cm long and 1.5 to 2 mm in diameter. They are light green and have a longitudinal pit on the top. The leaf blades are oblong-elliptical to oblong with at least in the middle almost parallel edges, and thin. They are 5 to 12 long and 2 to 4 cm wide. The base is wedge-shaped without colleter (glands), the apex pointed or pointed. The top is green to dark green, the bottom is a little lighter. In general, fresh leaves are lighter green than older leaves. The leaf nerve consists of a midrib that is lighter in color on the underside, but is not very clear on the upper side. Four to five secondary ribs each branch off from the central rib at a ± 45 ° angle. All vegetative parts excrete a white milky juice when injured.
The umbel-shaped inflorescence consists of 5 to 10 flowers, the top is convex. The gray-green, bald inflorescence stalk stands upright with a rachis which is bent downwards. It is 4 to 6 cm long with a diameter of 1.5 to 2 mm. The flower stalks are 2.5 cm long and 1 mm in diameter. They are very light green and bald. The sepals are not fused at the base, triangular to ovoid with a rounded tip. They are 1 to 1.2 mm long and 0.8 to 1 mm wide, cream-white or light green and bare. A colleter (gland) sits at the base of each sepal.
The white or pale yellow corolla is very flat, bell-shaped and almost round on the outside. It has a diameter of 10 to 14 mm in diameter. The corolla lobes are therefore broadly triangular with a slightly extended tip, 6 to 9 mm wide and 3.5 to 5 mm long. On the upper side a longitudinal pit runs to the tip of each petal tip. A longitudinal back is developed on the underside. They are bare outside, inside under the corolla the corolla is hairy downy. The white to yellowish-white secondary crown measures 6 to 7 mm in diameter and is 5.0 to 5.5 mm high. The tips are upright, viewed from above or in cross-section they are round to egg-shaped. The outer extension is concave with a pointed tip. The inner process is pointed. The flowers have a weak smell and visibly produce nectar after the second day. In culture, they remain open for 4 to 5 days.
The Pollinia are elliptically elongated, 500 to 550 μm and 100 to 150 μm wide; they get a little narrower towards the bais. The apex is rounded, the highest point is slightly shifted to the outside. A sterile and transparent border (without pollen) runs on the outside to just below the apex. The corpusculum is elliptical, 50 to 60 long and 25 to 30 μm wide with a point at the top. The caudiculae (translator arms) are almost rectangular in cross section, 90 to 100 μm long and 20 to 25 μm in diameter. They are twisted at the base.
Fruits and seeds are not known.
Similar species
Hoya narcissiflora differs from Hoya devogelii , Hoya gildingii , Hoya jiewhoeana , Hoya nuttiana and Hoya phyllura by the bald corolla; in the species mentioned, the corolla is hairy downy. In Hoya danumensis , the tips of the secondary crown are wider, higher and almost flat.
Geographical distribution and habitat
The species is so far only known from the type locality near Sanggau in West Kalimantan (Borneo island, Indonesia). It grows there in a rainforest from about 100 to 300 m above sea level.
Taxonomy
Hoya narcissiflora was first described by Sri Rahayu and Michele Rodda in 2017. The holotype was collected by Mr. Maskuran in February 2014 on a slope of a river in a primary rainforest near Sanggau at 100 to 300 m above sea level and cultivated in the Bogor Botanic Gardens. The holotype is kept in the herbarium of the Research Center for Biology in Cibinong, Indonesia (Sri Rahayu JQ705). One isotype was deposited at Kebun Raya Bogor in Bogor, Indonesia. The species name is derived from the similarity with the flowers in shape and color of the daffodil.
literature
- Sri Rahayu, Michele Rodda: Hoya narcissiflora (Apocynaceae, Asclepiadoideae), a new species from Borneo. Reinwardtia, 16 (1): 5-10, 2017.