Bull. Natn. Sci. Mus., Tokyo, Ser. B, 30(4), pp. 165–171, December 22, 2004

Three New Species of the Thai Impatiens(Balsaminaceae). Part 3
Tatemi Shimizu1 and Piyakaset Suksathan2
1Shimizu Botanical Laboratory, 211–3 Okada Matsuoka, Matsumoto, Nagano Pref., 390–0312, Japan
E-mail:tshimizu@bb.mbn.or.jp
2
Queen Sirikit Botanic Garden, Chiang Mai, Thailand

Abstract Three new species of Impatiens (Balsaminaceae) from Thailand, I. tribounii, I. phahompokensis, and I. phengklaii are described based on specimens deposited in the herbarium of theQueen Sirikit Botanic Garden, Thailand. I. tribounii and I. phahompokensis, are characterized byyellow flower and I. phengklaii is characterized by orenge-red one. I. tribounii and I. phengklaii
are endemic in Kanchanaburi, SW part of Tahiland, while I. phahompokensis is endemic in Chiang
Mai, N part of Thailand.
Key words : Thailand, Balsaminaceae, new species, Impatiens tribounii, Impatiens phahompokensis, Impatiens phengklaii.

Introduction
In 2001 February, we had an opportunity tomake cooperative taxonomic study of Impatiens
concerning to the specimens deposited in theherbarium of the Queen Sirikit Botanic Garden,
Chiang Mai, Thailand. In the study, we foundsome unnamed species of this genus. The present
paper aims to describe three of them as a reportof a serial study on the taxonomy of Impatiens ofThailand to be continued from the previous paper(Shimizu, 2000).
Results and Discussions
1. Impatiens tribounii T. Shimizu et P. Suksathan sp. nov.
Herba annua, caulis ascendant, 30–40 cm
altus, superiore viridis. Folia alterna, congesta,
lateral nervis prominent, longe petiolata, lamina
membranacea, elliptica vel ovatis, ad 20 cm
longa et 10 cm lata, glandulae 2, basi costa. Flores numerica in racemi longe pedunculata, alae
flavae sed lobis distalis rulber striates, axillares
solitarii vel bini, et pedicelli 1 cm longi, ad basis
bracteata, sepala lateralia 2, elliptica. Alae interse connatae, inter medio basi unicornata, bilo-batis ad apex. Ovaria glabra, 4-loculata, vexillum
1.1 cm longa 0.8 cm lata.
Erect succulent annual herb, young parts puberulent. Leaves light green with greenish-white
midribs, spirally arranged, congested on the topof stem; lamina elliptic-ovate up to 2010 cm,apex acuminate, base cuneate to acute, crenulate
to slightly serrate along margin, puberulous on
both surfaces, membranaceous, with two glands
at the base of midrib on lower surface, glands indistinct when dry; lateral veins up to 12 pairs;
petioles up to 14 cm long. Inflorescence a single
raceme of 7.5–8.5 cm long, subterminal, 10many-flowered, pedunculate, puberulent; peduncle ca. 26 cm long. Flowers bright yellow, 1–2 ineach bract, pedicelate of ca. 1 cm long, with 1–2
linear bracteoles of 3–4 mm long at the base;bracts lanceolate, 102.5 mm, apex long acuminate, margin entire to sharply serrate, with 2basal glands; lateral sepals 2, pale yellow, asymmetrically ovate, 106 mm, apex acuminate, puberulent on outer surface; lower sepals yellow,
with numerous reddish-orange spots inside, ca.
1 cm deep, spur yellow, turgid, shortly hooked,
ca. 6 mm long; dorsal petal yellow, elliptic-oblong, ca. 1.1 cm long, slightly curved backward,apex emarginated, with a short thorn-like point at

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the base of sinus, costa narrowly winged, green,
puberulent; lateral united petals connate, lower
petals bright yellow, ca. 107 mm, fused about
half of the length, upper petals yellow, with 5–6
orange-red sripes, 145 mm. Ovary glabrous, 4locules, vexillum 1.10.8 cm. Capsules clavate,ca. 1.5 cm long, glabrous (Figs. 4–6). Seeds 2–4,
heart-shaped, ca. 4 mm long.
Type: Kanchanaburi province, Thong Pha
Phum district, base of limestone range near WatPu Ye, P. Suksathan & P. Tribouni 3037, herb
grows on shady limestone in mixed bamboo forest, ca. 300 m Alt., Aug. 18, 2001 (Fig. 1), (holotype: QBG!).
Distribution: Endemic, known only fromthe type locality, rather rare.
It is one of the members of Semeiocardium
zolling (sect.) T. Shimizu, characterized by 4carpellate ovary, connate wing petals, and theyellow-orange color of flowers. No other Thai
species have bright yellow-orange flowers suchas this species.
2. Impatiens phahompokensis T. Shimizu etP. Suksathan sp. nov.
Herba 1 m altus. Folia vix congesta supra
caules, lamina 4.5–9.0 cm longa 2.1–3.9 cm lata;petiolis 3.8 cm longis sine stipula glande. Flores
valde flavi, axillares solitarii vel bini, et pedicelli
1.5–2 cm longi, sepala lateralia 2, elliptica, petalis superioribus rubro-maculatis.
Procumbent herb, ca. 40 cm high, wholly pubescent. Leaves alternate, somewhat congested
towards the upper part of stems; lamina elliptic toovate 4.5–9.02.1–3.9 cm, apex acuminate, basecuneate, crenulate to serrate along margin,
sparsely pubescent on both surface, chartaceous,basal glands absent or minute projections; lateralveins up to 14 pairs; petioles up to 3.8 cm long.
Flowers yellow with 2 red round patches on
upper lateral petals, axillary, solitary without peduncle, or in a pair with peduncle of ca. 2 cm
long, pedicels 1.5–2 cm long; lateral sepals 2,yellowish green, suborbicular, ca. 1.4 cm across,
apiculate, pubescent on outer surface; lower
sepals yellow, saccate, ca. 1 cm deep, inner sur-face glabrous, with or without pale red reticulateveins, outer surface pubescent, spur entirely yellow, ca. 3.3 cm long; dorsal petals yellow, ovateoblong, 1.61.4 cm, apex sometimes emarginated, costa broadly winged on the lower half, c5 mm wide; lateral united petals free, lower
petals yellow 127 mm, upper petals yellow
with one red patch at the middle of the lobe, ca.
13 mm long (Figs. 7–9). Ovary glabrous. Capsuleand seed not seen.
Type: Chiang Mai province, Mae Aai district, Doi Pha Hom Pok, ca. 1,800 m alt., P. Suksathan 1411, herb grows in light shade of marshy
steam banks in lower montane forest, Nov. 8,
1998 (holotype: QBG!, Fig. 2), (isotype: TNS).
Distribution: Endemic, known only fromthe type locality from altitude 1,700–2000 m., locally common.
3. Impatiens phengklaii T. Shimizu et P. Suksathan sp. nov.
Herba annua ca. 40 cm alta. Folia superiorecongesta, lamina oblancelata vel elliptica, posticus anguste ovata. Folia sub-membranacea, petiolus usque ad 18 cm, lamina usque ad 16.5 cm
longa 4–6 cm lata, margine crenata. Flores 2–8 incorymbasa, longe pedunculata, alae atro aurantiaca, axillares solitarii, et pedicelli 2 cm longi, adbasis bracteata, sepala lateralia 2, ovata.
Erect succulent perennial herb, ca. 40 cm high,wholly glabrous. Leaves spirally arranged, congested on the top of stem; lamina oblanceolate toelliptic rarely ovate, up to 16.54–6 cm, apexacuminate, long-cuneate at base, crenulate on
margin, with 2 glands at 1–2 cm above the base;lateral veins up to 8 pairs; petioles up to 18 cm
long. Inflorescences axillary, corymbose, 2–4–(8)-flowered, pedunculate; peduncles up to 18 cm
long. Flowers orange-red, bracteate; bracts elliptic 6–103–4 mm, apiculate, pedicels ca. 2 cm
long; lateral sepals 2, ovate, 12–148–10 mm,apiculate; lower sepals saccate, ca. 2 cm deep,
with dark red patch inside, spur short, hooked,turgid, ca. 1 cm long; dorsal petal broadly elliptic
1.81 cm; lateral united petals connate, entirely
orange, lower petals ca. 12 mm long, upper petals

Three New Species of the Thai Impatiens (Balsaminaceae). Part 3

Fig. 1.

Holotype of Impatiens tribounii.

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Tatemi Shimizu and Piyakaset Suksathan

Fig. 2.

Holotypoe of Impatiens phahompokensis.

Three New Species of the Thai Impatiens (Balsaminaceae). Part 3

Fig. 3.

Impatiens phengklaii.

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Tatemi Shimizu and Piyakaset Suksathan

Fig. 4. Front view of flowers of Impatiens tribounii showing yellow upper petals with 5–6 orange-red stripes(holotype).
Fig. 5. Whole plant of Impatiens tribounii showing radical leaves (holotype).
Fig. 6. Lateral view of Impatiens tribounii showing short spur (holotype).
Fig. 7. Oblique front view of a flower of Impariens phahompokensis showing red patches on upper lateral petal(holotype).
Fig. 8. Front view of a flower of Impariens phahompokensis (holotype).
Fig. 9. Lateral view of a flower of Impariens phahompokensis showing long spur of the lip (holotype).

Three New Species of the Thai Impatiens (Balsaminaceae). Part 32010 mm. Ovary glabrous. Mature capsule andseed not seen.
Type: Kanchanaburi province, between
Huay Ban Kao and Kritee, R. Geesink & C.
Phengklai 6093. July 4, 1973, 500 m alt., Bamboo dominated mixed deciduous forest in limestone hills (holotype: P!, Fig. 3, Isotype: AAU!)
Distribution: Endemic, known only fromthe type locality.
This species also characterized by flowers with
united lateral petals, orange in color and long
petioles as well as peduncles up to 18 cm long. Itis also grows in limestone area as the mostspecies of Semeiocardium do.

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Acknowledgement
We would like to thank curators of AAU andQBG herbarium for permission and facilitation
to study. Thanks also giving to Mr. Methee
Wongnak and Mss. Ratchuporn Spanuchat for
preparing specimens and several kinds of help in
the fields.
References
Shimizu, T., 1991. New Species of the Thai Impatiens (1).
J. Jap. Bot., 66: 166–177.
Shimizu, T., 2000. New Species of the Thai Impatiens(Balsaminaceae) 2. Bull. Natn. Sci. Mus., Tokyo, Ser. B,
26 (2): 35–42.