Bull. Natl. Mus. Nat. Sci., Ser. B, 35(2), pp. 51–56, June 22, 2009

Studies of Sino Himalayan Impatiens (Balsaminaceae) II.
A New Species and a New Form Similar to Impatiens racemosa DC.
from Nepal Himalaya
Shinobu Akiyama1, Hiroshi Ikeda2 and Sunil Kumar Acharya3
1

Department of Botany, National Museum of Nature and Science, Amakubo 4–1–1, Tsukuba 305–0005, Japan
E-mail: akiyama@kahaku.go.jp
2
Department of Botany, University Museum, University of Tokyo, Hongo 7–3–1, Tokyo 113–0033, Japan3
Department of Plant Resources, Kathmandu, Nepal

Abstract A new species of Impatiens, I. recticalcarata S. Akiyama (Balsaminaceae), with a newform, f. alba S. Akiyama (Balsaminaceae), from the Sino Himalaya region of Nepal, is describedand illustrated. Impatiens recticalcarata is similar to I. racemosa DC. but differs in having thestraight spur and the wide, semiovate distal lobes of the lateral united petals and lacks red dots. A
comparison table of the species similar to I. racemosa in Nepal is given.
Key words : Himalaya, Impatiens, Nepal, new species, Sino Himalaya.

Since 1983 we have been studying Himalayan
Impatiens (Balsaminaceae), particularly in Nepal(Akiyama et al., 1991). Impatiens is one of themost diversified genera in the Himalaya. InNepal about 40 species have been recorded(Hara, 1979). During our field surveys in theSino Himalayan region we noticed that some collections represent species not yet described. During preparation of the treatment of Impatiens forthe forthcoming Flora of Nepal the first author,
Akiyama, became aware of an undescribed
species similar to Impatiens racemosa DC fromBimtang, collected at 3770 m elevation by Ikeda
and Acharya and others in 2008.
The new species, here named Impatiens recticalcarata, is characterized by a racemose inflorescence with several small flowers classified as‘type 1a’ (Akiyama and Ohba, 2000), an inflorescence type shared with I. racemosa, but differingfrom the latter in having a straight spur with adownward pointing apex, yellow or creamy whitelateral united petals without red dots, and wide,semiovate (not distinctly bilobed) distal lobes
with an acute apex and nearly orbicular basal
lobes with rounded apex of the lateral unitedpetals. Terminology for the flowers follows

Akiyama et al. (1991) and for the inflorescence
Akiyama and Ohba (2000).

Impatiens recticalcarata S. Akiyama, sp. nov.
[Figs. 1–4]
Impatienti racemosae DC. similis, sed calcari
rectiore et lobis distalibus petalorum unitorumlateralium semilatiovatis apice acutis, nec profunde bilobis bene differt.
Type: Nepal. Manang District, Bimtang–Gho,
28°3744N 84°2821E, 3770 m (H. Ikeda, S. K.
Acharya, T. Kawahara, M. N. Subedi, N. Yamamoto, K. Yano, and M. Watson 20811254, 14Aug. 2008, KATH-holo, TI, TNS-iso).
Plants 40–85 cm tall. Stem branched, glabrous.
Leaves alternate, petiolate or sessile distally;
petiole to 2 cm long, usually with glands at base;leaf blade ovate to narrowly ovate, 4.5–5.5
1.5–2 cm, base attenuate, margin crenate-serratewith dense short glandular hairs (and/or glands),
apex acuminate, both surfaces glabrous, uppersurface green, lower surface slightly glaucous.
Inflorescences in axils of distal leaves, standard
racemes, ascending, to 4 cm long, 5 or 6(–8)flowered; peduncle to 2 cm long, glabrous;

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Shinobu Akiyama, Hiroshi Ikeda and Sunil Kumar Acharya

Fig. 1. Impatiens recticalcarata S. Akiyama f. recticalcarata (a–c), I. recticalcarata S. Akiyama f. alba S.
Akiyama (d, e), and I. racemosa DC. (f, g). a–e: In Bimtang, on 14 Aug. 2008. f: In Philim, on 29 July 2008.
g: In Gho, on 15 Aug. 2008.

Studies of Sino Himalayan Impatiens (Balsaminaceae) II

Fig. 2. Isotype of Impatiens recticalcarata S. Akiyama (H. Ikeda, S. K. Acharya, T. Kawahara, M. N. Subedi, N.
Yamamoto, K. Yano, and M. Watson 20811254, 14 Aug. 2008, TNS).

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Shinobu Akiyama, Hiroshi Ikeda and Sunil Kumar Acharya

Fig. 3. Impatiens recticalcarata S. Akiyama (H. Ikeda, S. K. Acharya, T. Kawahara, M. N. Subedi, N. Yamamoto, K. Yano, and M. Watson 20811254, 14 Aug. 2008, TNS). a: Flower (lateral view). b: Dorsal petal (folded). c: Dorsal petal (opened). d: Lateral united petals. e: Lower sepal. f: Lateral sepal (outer). g: Lateral sepal(inner). h: Anthers. All4.

Studies of Sino Himalayan Impatiens (Balsaminaceae) II

pedicels ca. 6–8 mm long, glabrous, with a bractat base; bracts persistent, ovate, ca. 2.5 mm long,apex acute.
Flowers yellow (f. recticalcarata) or creamy
white (f. alba), without red dots, ca. 2.5 cm deep,ca. 2.2 cm long. Lateral sepals 2 or 4, inner ones
minute or absent, outer ones ovate, ca. 4 mm long(including elongated apex), apex long acuminate,awned. Lower sepal yellow or creamy white
without reddish veins, navicular with longstraight spur with downward oriented apex, ca.
18 mm in overall length. Dorsal petal yellow or
creamy white, compressed, elliptic, ca. 7 mm
long, ca. 9 mm wide when flattened, distinctly cucullate, apex obtuse or slightly retuse, midvein

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slightly thickened on outside and minutely projected near apex. Lateral united petals yellow or
creamy white, without red dots, ca. 17 mm long;
basal lobe nearly orbicular, ca. 5.55 mm, apex
rounded; distal lobe widely ovate, ca. 138 mm,apex acute, not distinctly bilobed, margins slightly undulate; appendage indistinct. Filaments linear, slightly hooked at apex; anthers ovoid, connective glabrous. Ovary linear. Flowers in August.
Habit: On mossy wet rocks beside streams.
Distribution: Nepal. Manang District, Bimtang(known only from the type locality).

Fig. 4.

Distribution of Impatiens recticalcarata S. Akiyama (.) and I. racemosa DC. () in Nepal.

Table 1.

Comparison among a new species, Impatiens recticalcarata, I. racemosa, and I. radiata.

Inflorescence
Flower color
Basal lobe of lateral
united petals
Distal lobe of lateral
united petals
SpurI. recticalcarata

I. racemosa

I. radiata

uninterrupted raceme
yellow or creamy white
without red dotsnearly orbicular

uninterrupted raceme
yellow with red dots
obovateinterrupted raceme
pale purplish white with
red dots
widely obovate

widely semiovate withacute apex
straight with downwardly
oriented apex

bilobed with obtuse apex

bilobed with obtuse apex

curved downward

straight

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Shinobu Akiyama, Hiroshi Ikeda and Sunil Kumar Acharya

f. alba S. Akiyama, forma nov.
[Figs. 1 d, e]Floris albis, cetera ut in typo.
Type: Nepal. Manang District, Bimtang–Gho,
28°3744N 84°2821E, 3770 m (H. Ikeda, S. K.
Acharya, T. Kawahara, M. N. Subedi, N. Yamamoto, K. Yano, and M. Watson 20811255, 14
Aug. 2008, KATH-holo, TI, TNS-iso).
Habit: On mossy wet rocks beside streams.
Distribution: Nepal. Manang District, Bimtang(known only from the type locality).
Impatiens recticalcarata belongs to the group
we refer to as the I. racemosa-group, which includes I. racemosa, I. radiata, and allied species.
Impatiens racemosa is common in the Nepal Himalaya. Impatiens radiata, also common in theregion, resembles I. racemosa but differs in having interrupted racemes and pale purplish whiteflowers with a straight spur. Impatiens recticalcarata is also related to I. radiata in having astraight spur and often white flowers, but differs
in the uninterrupted inflorescences, yellow or
creamy white lateral united petals, and the wide
semiovate distal lobes with an acute apex and thenearly orbicular basal lobes with rounded apex of
the lateral united petals. The differences between
these three species is summarized in Table 1. A
considerable number of species belonging to theI. racemosa-group occurs in China, but the composition of this group is still controversial.
It is very interesting that some individuals of I.
recticalcarata in the same locality have yellow
flowers and others have creamy white flowers. In

Impatiens it is very rare to have different flower
colors within a single species.
Acknowledgement
We are indebted to Dr. Hideaki Ohba, Professor Emeritus, University of Tokyo for promoting
the field surveys and for his constant encouragement. We are grateful to Dr. Sharma, Director,
Department of Plant Resources, for his approving
our cooperative research project. We are also
grateful to Dr. David E. Boufford, the Harvard
University Herbaria, for reading the manuscript.
The field survey was supported by a Grant-inAid for Scientific Research (A) from the Japan
Society for the Promotion of Science, no.
18255004 in 2008 and 2009 (to Hideaki Ohba,Professor Emeritus, the University of Tokyo).
References
Akiyama, S. and H. Ohba. 2000. Inflorescences of the Himalayan species of Impatiens (Balsaminaceae). Journalof Japanese Botany. 75: 226–240.
Akiyama, S., H. Ohba and M. Wakabayashi. 1991. Taxonomic notes of the East Himalayan species of Impatiens. Studies of Himalayan Impatiens (Balsaminaceae)(1). In: Ohba, H. and S. B. Malla. (eds.), The Himalayan Plants. 2: 67–94. University of Tokyo Press,Tokyo.
Hara, H. 1979. Balsaminaceae. In: Hara, H. and L. H.
Williams (eds.), An Enumeration of the Flowering
Plants of Nepal. 2: 78–80. British Museum (NaturalHistory), London.