Phytotaxa 543 (3): 181–187
Copyright © 2022 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Harsh Singh: 30 Mar. 2022; published: 14 Apr. 2022
Impatiens jacobdevlasii (Balsaminaceae), a new species from Knuckles massif of
CHAMPIKA BANDARA1,*, SANATH BANDARA HERATH2, BHATHIYA GOPALLAWA3,4 & ACHALA
1 Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, Nugegoda 10100, Sri Lanka.
2 The Open University of Sri Lanka, Nawala, Nugegoda 10250, Sri Lanka.
3 National Herbarium, Department of National Botanic Gardens, Peradeniya 24000, Sri Lanka.
4 Postgraduate Institute of Science, University of Peradeniya, Peradeniya 24000, Sri Lanka.
5 Department of National Botanic Gardens, Peradeniya 24000, Sri Lanka.
*Author for correspondence:
Impatiens jacobdevlasii Herath, C. Bandara & Gopallawa sp. nov. (Balsaminaceae), a new species from Knuckles (Dumbara)
massif of Sri Lanka is described and illustrated. The detailed morphological characters, diagnostic comparisons, notes on
habitat and ecology are presented. According to the IUCN Red List Categories and Criteria, I. jacobdevlasii is assessed as
Critically Endangered (CR) by virtue of its limited distribution range and decline of mature individuals.
Keywords: Balsam of Sri Lanka, biodiversity, conservation, Dumbara, taxonomy
The family Balsaminaceae comprises with two genera, Impatiens Linnaeus (1753: 937) and monotypic Hydrocera
Blume (1825: 241) ex Wight & Arnott (1834: 140) (Mabberley 2008; Bhaskar 2012). The genus Impatiens L. is
distributed in the tropical and subtropical regions of the Old World as well as in the Northern temperate regions
containing over 1000 species (Grey-Wilson 1980; Mabberley 2008; Ruchisansakun et al. 2018).There are five distinct
distribution hotspot areas of Impatiens in the world; Eastern Himalayas, South-east Asia, tropical Africa, Madagascar,
Southern India and Sri Lanka (Yuan et al. 2004). Southern India and Sri Lanka region (Western Ghats) also show a
higher degree of endemism and hence recognised as one amongst the 34 biodiversity hotspot regions in the world
(Mittermeier et al. 2004).
In Sri Lanka, 25 Impatiens species and subspecies have been enumerated in previous works with three introduced
species (Arnott 1836; Thwaites 1858; Hooker 1875; Trimen 1893; Grey-Wilson 1985). Sixteen species and three sub
species are endemic to the Island and unluckily, two Critically Endangered (CR), nine Endangered (EN), six Vulnerable
(VU) species and one Possibly Extinct [CR (PE)] species and subspecies are listed among them (The National Red List
During a botanical expedition, a population of an interesting species of Impatiens was recorded from Dothalugala
Mountain, Knuckles Massif, Kandy District, Sri Lanka on 11 August 2016 by the second author and the second
population was recorded by the third author from Thangappuwa, Knuckles Mountain range, Kandy District, Sri Lanka
on 02 June 2019. After critical study and comparison with its closely allied species, Impatiens truncata Thwaites
(1858: 66) from Sri Lanka, type specimens and descriptions revealed that it differs from the latter and is therefore
described here as a new species. Prior to the current taxonomic treatment, images of this species published under an
unpublished species (Impatiens sp. 2) in ‘Illustrated field guide to the flowers of Sri Lanka; Vol. 3 (de Vlas 2019). A
fieldwork was conducted in October 2018 and collected plants were prepared for making herbarium specimens. All
BANDARA ET AL.
182 • Phytotaxa 543 (3) © 2022 Magnolia Press
floral parts were measured and described using terminology in Ruchisansakun et al. (2018). Canon EOS 5D Mark IV
and Nikon D850 DSLR camera bodies fitted with Canon 100 mm macro and 24–120 mm lenses were used for taking
digital photographs for the colour plates.
Impatiens jacobdevlasii Herath, C. Bandara & Gopallawa sp. nov. (Figs. 1‒3 & 4 I–P)
Type:—SRI LANKA, Central Province, Kandy District, Dothalugala Mountain, on the ground among rocks and mosses along stream,
1375 m a.s.l., 13 October 2018, Sanath Herath & Champika Bandara 2018-05. (holotype PDA!); Central Province, Kandy District,
Thangappuwa–Alugallena nature trail, along shady embankments of the trail, 1512 m a.s.l., 02 June 2019, NBS/2019/OL/TGP/009.
Diagnosis: Impatiens jacobdevlasii morphologically similar to I. truncata but differs by having pinkish or purplish
color flowers with pink margin, bilobed upper petal of lateral united petals and yellow color centre blotch, linear-
lanceolate lateral sepal, 4–6 lateral nerve pairs, abaxially scattered pubescent and adaxially glabrous lamina.
FIGURE 1. Impatiens jacobdevlasii; A. Mature individuals in the natural habitat, B. front view of the flower, C. Lateral view of the
flower, D. Rear view of the flower, E. Capsule. Photographs by Sanath Bandara Herath (A), Bhathiya Gopallawa (B–E).
A NEW SPECIES OF IMPATIENS JACOBDEVLASII Phytotaxa 543 (3) © 2022 Magnolia Press • 183
FIGURE 2. Impatiens jacobdevlasii; A. Plant habit (holotype: Sanath Bandara & Champika Bandara 2018-05), B. Developing flower
bud, C. Front view of a flower, D. Lateral view of the flower, E. Dorsal petal, F. Lateral view of dorsal petal, G. Lower sepal, H. Lateral
sepals, I. Lateral united petal, J. Androecium, K. Mature capsule. Illustrations by Champika Bandara.
BANDARA ET AL.
184 • Phytotaxa 543 (3) © 2022 Magnolia Press
FIGURE 3. Color variations of Impatiens jacobdevlasii flowers; A. White color, B. Light purple color, C. Light pink color, D. Deep pink
color. Photographs by Bhathiya Gopallawa.
Description: Herb, Perennial, 30–60 cm tall; stem pale greenish, swollen at nodes, cylindrical, glabrous. Leaves
simple, spirally arranged, lower part often naked and often crowded towards apex of stem, petiolate; Petiole ca. 2–3 cm
long, glabrous, pale green; stipule minute, ca. 0.5–1 mm. Lamina lanceolate or elliptic-lanceolate, 2–8 (–10) × 1.5–3.5
(–4.5) cm, base subattenuate, acuminate at apex; adaxially dark green color with scattered minute hairs, abaxially
pale green, glabrous, margin crenate or serrate with a single narrow tooth; setulose in between marginal teeth. Lateral
nerves in 4–6 (–7) pairs, sub-opposite, prominent. Flowers solitary in the upper leaf axils, simple, pale pinkish or
purplish with pink margins and rarely white. Peduncle 2.5–3.5 cm long, thin, pale green, scattered pubescent. Lateral
sepals 2, linear-lanceolate, 3.5–4 × 0.7–0.9 mm, glabrous, slightly curved, pale green, pinkish towards apex, margins
entire. Lower sepal 13–15 × 6–8 mm, navicular, white externally and internally with yellow patch at the centre, 1 mm
long mucronate at apex; spur 3–4 mm long, pale yellowish, straight, cylindrical. Dorsal petal cucullate, 9–10 × 6–7
mm, concave, dorsally with a narrow crest terminating in a short pointed appendage, ca. 1.5–2 mm. Lateral petals
united, 20–25 × 8–10 mm, 2-lobed; base of united lateral petals with yellowish blotch, upper petals about one-third the
size of the lower petals; upper petal 7–9 × 5–7 mm, apex equally bilobed, pinkish or purplish shade towards apex and
yellowish blotch in the centre; lower petal 15–18 × 8–10 mm, semi-oval, often notched at apex, base and inner margin
of the distal lobes with minute pinkish or whitish ridge of papillae. Androecium 4–5 × 2 mm, glabrous, white. Stamens
5, connate, surrounding gynoecium. Filament ca. 1 mm, glabrous, white; style glabrous, ca. 0.5 mm long. Capsule
green, 10–12 × 5–7 mm, broadly fusiform, 5-angled, pilosulose, apex acute, rostellate, fleshy; Seeds 1–4, 5–7 × 3–5
mm, obovoid, slightly compressed.
Distribution: Impatiens jacobdevlasii is known from Dothalugala Mountain and Thangappuwa area in Knuckles
massif of Sri Lanka.
Habitat and ecology: Impatiens jacobdevlasii is known only from two locations in South-eastern region of
Knuckles massif. Small populations of this species are distributed in the reported area. The overall number of mature
individuals is estimated as ˂80 in the both populations from field observation. Both locations are belongs to lower
montane evergreen forests at elevation of 1300–1500 m a.s.l. (Gunatilleke and Ashton 1987). One population was
recorded from Dothalugala Mountain (1375 m a.s.l.) with ˂30 individuals and other from Thangappuwa (1512 m
a.s.l.), population comprise with 2–3 subpopulations; 10–15 individuals per each. The new species is usually found
on the ground among mosses and rock boulders along streams. This species mostly refer well-shaded forest cover and
associated species are Rhynchoglossum notonianum (Wall) B.L. Burtt (1962: 170), Strobilanthes sexennis Nees (1837:
312), Ophiorrhiza pectinata Arnott (1836: 338), Phaius wallichii Lindle (1831: 46) and Begonia malabarica Lamarck
In the wild, this new species facing threat of extinction due to the low number of plants representing the entire
population, population decline and its limited distribution. Dothalugala population shows significant decrease through
the 2016–2022 period, approximately 80% of the population.
The habitats of the new species associated with existing nature trails in Knuckles mountains (Bambaradeniya &
Ekanayake 2003). Dothalugala population located near a stream in existing Deanston–Dothalugala nature trail and
Thangappuwa population located in wet, rocky surfaces along the existing Thangappuwa–Alugallena nature trail.
Any situation in road clearing, weeding, constructions or maintaining, authorities should focus the attentions for
management and further conservation attempts on this new species.
Thus, I. jacobdevlasii has a great potential for horticultural applications due to its wide color range of flowers
(Fig. 3) and few plants were cultivated at Royal Botanical Garden, Peradeniya, Sri Lanka.
Phenology: Flowering and fruiting all around the year.
A NEW SPECIES OF IMPATIENS JACOBDEVLASII Phytotaxa 543 (3) © 2022 Magnolia Press • 185
FIGURE 4. Comparison of Impatiens truncata (A–H) with I. jacobdevlasii (I–P). (A, I). Front view of flower, (B, J). Dorsal petal, (C,
K). Lateral sepals, (D, L). Lateral united petals, (E, M). Pedicel with androecium, (F, N). Front view of lower sepal, (G, O). Lateral view
of the lower sepal, (H, P). Capsules. Photographs by Bhathiya Gopallawa.
BANDARA ET AL.
186 • Phytotaxa 543 (3) © 2022 Magnolia Press
Etymology: The specific epithet is named in honour of Dr. Jacob de Vlas, a Dutch biologist and the author of
the tri-volume series of the ‘Illustrated field guide to the flowers of Sri Lanka’ in 2008–2019 documenting over 3000
native and introduced species of the Island. The common name for the species is Vlas’s balsam.
Proposed IUCN conservation assessment: Based on current knowledge, the Extent of Occurrence (EOO) and
Area of Occupancy (AOO) was estimated using GeoCAT (Moat 2007) as ~2 km2 and 12 km2 respectively. From
the available data, we classify I. jacobdevlasii as ‘Critically Endangered’ (CR: B1+B2b (ii,iii,v); C2a (i,ii); D) in
accordance with IUCN guidelines (IUCN 2019).
Additional specimens examined: SRI LANKA. Impatiens truncata:—MATALE DISTRICT: Midlands Estate
to Laggala, 700 m a.s.l., Nov. 1978, Grey-Wilson & Silva 3002 (PDA!); Matale to Illukkumbura road, July 1974,
Sumithraarachchi 418 (PDA!). KANDY DISTRICT: Corbet’s Gap, Rangala to Looloowatte (Loolwatte), 1300 m
a.s.l., September 1969, Grupe 237 (PDA!); Kalupahana Forest, Knuckles Mts., 1250 m a.s.l., July 1973, Jayasuriya &
Balasubramaniam 1220 (PDA!); Hantana, s. coll. C.P. 2426, pro parte (PDA!);. NUWARA ELIYA DISTRICT: between
Ramboda and Nuwara Eliya, 1500 m a.s.l., Nov. 1978, Grey-Wilson & Wickramasinghe 3035 (PDA!); Pattipola to
Farr Inn, Horton Plains, Nov. 1973, Sohmer, Jayasuriya & Eliezer 8523 (PDA!). Impatiens jacobdevlasii:—KANDY
DISTRICT: Thangappuwa–Alugallena nature trail, Knuckles Mt., 1540 m a.s.l., December 2019, Champika Bandara
& Shashee Dilrukshi 2019-13 (PDA!)
We are very grateful to Dr. Shelomi Krishnarajah, Director General of the Department of National Botanic Gardens,
Dr. Subhani Ranasinghe, Deputy Director, National Herbarium of Sri Lanka (PDA) and the staff for their support. This
study financially supported by ‘Hill top Flora’ and Recovery plan on ‘Osbeckia lanata’ projects. We also thanks Mrs.
Shashee Dilrukshi for the logistic support in the field.
Arnott, G.A.W. (1836) New species of Indian Balsaminaceae. Companion to the Botanical magazine 1: 320–325.
Bambaradeniya, C.N.B. & Ekanayake, S.P. (2003) A Guide to the Biodiversity of Knuckles Forest Region. IUCN–The World Conservation
Union, Sri Lanka Country Office, Colombo, Sri Lanka. vi + 68 pp.
Bhaskar, V. (2012) Taxonomic Monograph on Impatiens L. (Balsaminaceae) of Western Ghats, South India: the Key Genus for Endemism.
Bangalore: Centre for plant taxonomic studies. 283 pp.
de Vlas., J. (2019) Illustrated field guide to the flowers of Sri Lanka. Volume 3. J. de Vlas, The Netherlands. 320 pp.
Grey-Wilson, C. (1980) Impatiens of Africa. Rotterdam, Balkema.
Grey-Wilson, C. (1985) Balsaminaceae. In: Dassanayake, M.D. & Fosberg, F.R. (Ed.) A revised handbook of the Flora of Ceylon. Amerind
publication Co. Pvt. Ltd., New Delhi. pp. 76–120.
Gunatilleke, C.V.S., Ashton, P.S. (1987) New light on the plant geography of Ceylon. II. The ecological biogeography of the lowland
endemic tree flora. Journal of Biogeography 14 (4): 295–327.
Hooker, J.D. (1875) Impatiens L. In: Flora of British India 1. L. Reeve & Co., London, UK. pp. 440–464.
IUCN Standards and Petitions Committee (2019) Guidelines for Using the IUCN Red List Categories and Criteria. Version 14. Prepared
by the Standards and Petitions Committee; https://www.iucnredlist.org/documents/RedListGuidelines.pdf (accessed on 12 December
Mabberley, D.J. (2008) The plant book: a portable dictionary of the vascular plants. 3rd edition. Cambridge: Cambridge University
Mittermeier, R.A., Robles, G., Hoffman, M., Pilgrim, J., Brooks, T., Mittermeier, C.G., Lamoreux, J. & da Fonseca, G.A.B. (Eds.) (2004)
Hotspots revisited: Earth’s biologically richest and most threatened terrestrial ecoregions. CEMEX, Mexico DF.
Moat, J. (2007) Conservation assessment tools extension for Arc View 3.x, version 1.2. GIS Unit, Royal Botanic Gardens, Kew. Available
from: http://www.rbgkew.org.uk/gis/cats (accessed 10 January 2020)
The National Red List (2021) Conservation Status of the Flora of Sri Lanka 2020. Sri Lanka: Biodiversity Secretariat, Ministry of
Environment and the National Herbarium, Department of National Botanic Gardens, xviii + 254 pp.
Ruchisansakun, S., Suksathan, P., van der Niet, T., Smets, E.F., Saw-Lwin & Janssens, S.B. (2018) Balsaminaceae of Myanmar. Blumea
A NEW SPECIES OF IMPATIENS JACOBDEVLASII Phytotaxa 543 (3) © 2022 Magnolia Press • 187
Trimen, H. (1893) A Handbook to the flora of Ceylon 1. Dulau & Co. London.
Thwaites, G.H.K. (1858) Enumeratio Plantarum Zeylaniae. Dulau & Co., London. pp. 65–68.
Yuan, Y.M., Song, Y., Geuten, K., Rahelivololona, E., Wohlhauser, S., Fischer, E., Smets, E. & Küpfer, P. (2004) Phylogeny and
biogeography of Balsaminaceae inferred from ITS sequence data. Taxon 53: 391–403.