Friday, September 16, 2022

[Botany • 2018] Impatiens hukaungensis (Balsaminaceae) • A New Rheophyte from northern Myanmar [New or Noteworthy Plant Collections from Myanmar (10)]


Impatiens hukaungensis J. Murata & Nob. Tanaka, 

in Tanaka, Ohi-Toma, Ito, Aung & Murata, 2018. 

A new species, Impatiens hukaungensis J. Murata & Nob. Tanaka (Balsaminaceae), is described from Kachin State, northern Myanmar. This species is characterized by decumbent stem, oblanceolate leaves, 2-flowered simple raceme, white with purple mottled dorsal petal and purple dolabriform lateral united petals. Morphological characters, including its 2-flowered raceme and short fusiform capsules, as well as results of molecular phylogenetic analyses based on sequences of plastid atpB-rbcL region, suggest this new species belongs to Impatiens sect. Uniflorae Hook. f. & Thomson. It shows a rheophytic habit and grows along streams with high water-level differences.

Key words: Balsaminaceae, Impatiens, Kachin, Myanmar, rheophyte.


Impatiens hukaungensis J. Murata & Nob. Tanaka.
A. Habit showing rheophytic characters. B. Front view of a flower. C. Side view of a flower. D. Upper view of a flower. E. Floral parts dissected. 1. Dorsal petal. 2, 3. Outer lateral sepals. 4, 5. United lateral petals and inner lateral sepal. 6. Lower sepal and spur. F. Habitat, I. hukaungensis is growing on rocks along the stream. The water level is changeable due to the rainfall, and sometimes the plant is submerged. Scale: 1 cm.

Impatiens hukaungensis J. Murata & Nob. Tanaka, sp. nov.

Diagnosis: This species has morphologically similar species hitherto described from Myanmar and its adjacent regions based on flowers. It is well characterized by a combination of the following characters; decumbent habit, narrowly oblanceolate leaves, 2-flowered simple raceme, white with purple mottled dorsal petal and purple dolabriform lateral united petals.

Etymology: The specific epithet is derived from the type locality, one of the largest nature reserves in Myanmar, Hukaung Valley Tiger Reserve. 


 
Nobuyuki Tanaka, Tetsuo Ohi-Toma, Yu Ito, Mu Mu Aung and Jin Murata. 2018. New or Noteworthy Plant Collections from Myanmar (10): Impatiens hukaungensis (Balsaminaceae), A New Rheophyte from the Northern Region. Journal of Japanese Botany. 93(1); 23–30. 
http://www.jjbotany.com/pdf/JJB93-1_23-30.pdf