植物研究雑誌

J. Jpn. Bot.

77: 96-100 (2002)

A New Species of Symplocarpus (Araceae) from Nagano Prefecture， Central Japan

Koichi OTSUKA¥ Ryuichi WATANABEb and Ken INOUEc

aNagano Nature Conservation Research Institute， 2054-120 Kitago， Nagano， 381-0075 JAPAN;

bFacullty oi Education， Shinshu University， Nishinagano， Nagano， 380-8544 JAPAN;

CBiological Institute and Herbarium， Faculty of Science， Shinshu University， Asahi 3-1-1， Matsumoto， 390-8621 JAPAN

(Receivd on October 5， 2001)

A new species of Symplocarpus from northem N agano of central J apan， S. nabekuraensis， is described. This species has reniformed leaf blade similar to S. foetidus V紅 .latissimus， but its leaf blades and spathes are much smaller. Its size and form of spathes are similar to S. nipponicus， but their leaf forms differ from each other. Phenology of S. nabekuraensis differs from the above two species. Flowers mature after development of leaf blade in early summer， fruits mature in the same summer， and leaves wither in autumn.

Key words: Araceae， central Japan， northem Nagano， Symplocarpus nabekuraensis.

Generally two or three species紅 erecog-

nized in Symplocarpus from eastem Asia and

North America (Ohwi 1978， Ohashi 1982) and two species in Japan， S. foetidus Nutt. var. latissimus (Makino) H.Hara (= s. renifolius Schott ex Miq.) and S. nipponicus Makino. In June of 1987， one of the authors， Ryuichi Watanabe， found plants of Symplocarpus from Mt. N abekura of Iiyama City locating at the northem N agano Pref.，

which were different from S. foetidus v訂.

latissimus and S. nipponicus in several char-

acters.

They have reniform leaf blades similar to

those of S. foetidus， but their leaves includ-

ing petioles 30 to 70 cm long， and are nearly half or a little longer than half of those of S.

foetidus. Their spadices are very similar to those of S. nipponicus， small and approxi-

mately 10 cm long including spathes. More

conspicuous characteristic of the Mt. Nabekura plants is observed in their phenology and morphology of inflorescence，

that is， their leaves and spadices emerge from ground simultaneously， flowers mature after unfolding of leaves， and the whole of

their spathes紅 eabove the ground， as they have relatively long peduncles. On the other hand， spadices of S. foetidus emerge before leaves， and spadices of S. nipponicus appe訂

after development of leaves. In addition，

allozyme patterns among the three differ definitely (Inoue unpublished). Thus， we

concluded that the plants of Mt. N abekura to

be a new species， Symplocarpus nabekura-

ensis. The diagostic characters among the

above three species are listed in Table 1.

Mt. Nabekura and the surrounding areas

are heavily snowy regions. The紅eas訂e

dominated with deciduous broad-leaved for-est such as F agus crenata and Quecus

crispula， and are known as huge trees of Fagus crenaωgrow. Although S. nipponicus

grows in a foot of Mt. Nabekura， there are no reports that S. foetidus grows nearby. Several localities of S. nabekuraensis have been dis-

-96-

Apri12002 Journal of Japanese Botany Vol. 77 No. 2 97

Fig. 1. Type of Symplocarpus nabekuraensis Otsuka & K.Inoue.

covered surrounding Mt. N abekura until now; tens to hundreds individuals have been found in each locality. This species is con-

sidered to be adaptive to or relic to heavy snow environment， and may be found in similar habitats.

98 植物研究雑誌第77巻第2号 平成14年4月

Table 1. Comparison of three species of Symplocarpus in Japan

凸Up

e

q

u

p

しv

h

n

nB

ロL

e

h培

d

g

e

h泊

m

hulkρuv

pT-APT-APT且

aaa

ρU

凸l

u

P

U

L

L

L

S. foetidus var. latissimus S. nabekuraensis S. nipponicus

cordiform reniform-cordate ovate

50-120 cm 30-70 cm 20-50 cm

after emergence of spathe simultaneous with spathe before emergence of

emergence spathe

autumn autumn su町lmerWithering season of

leaves

Spathe length 15-20 cm

Spathe position basal part in the ground Apex of spathe elongate and pointing side-

ways

Fruiting season same season with f1ower-mg

P

A

r

u

t

w

時

お

.，.A

l

i

-唱・-W

4

E

t

E

h

H

u

m山

川

し

u

u

α

w

m

P

1

σ

b

x

う

d

山

m

Iuna

-da

田

町U

S

い

V

P

3

〈

mddML

1

0

0

細

目

g

4油

泊

wu-m

4-7 cm basal part in the ground short and pointing up-

wards

next season of f10wering

B A

D

Fig. 2. Flower and fruit of Symplocarpus nabekuraensis. A: Spadix with spathe in flowering stage. B:

Flower. C: Spadix with peduncle in fruiting stage. D: Fruit. Materials from type locality. A， B， 8 July

2001. C， D: 7 Aug. 2001. Scale: A ，C， 1 cm; B， D， 3 mm.

Symplocarpus nabekuraensis Otsuka &

K.Inoue， sp. nov. Symplocarpo foetido Nutt. v訂 .latissimo

(Makino) H.Hara et S. nipponico Makino similis， sed a priore spatha multo parviore， a posteriore lamina folii reniformi， ab ambabus

temporibus florentibus et fructicantibus differt.

Type: Japan， Honshu， Nagano Pref.， Iiyama City， Mt. Nabekura， Sekita Pass， alt. 1100 m， 29 June 2001， K. Otsuka 21951 (holo TI-Fig. 1， iso KANA， KYO， NAC，

Apri12002 Journal of Japanese Botany Vol. 77 No. 2 99

SHIN).

Other specimens exarnined: JAPAN， Nagano Pref.，

Iiyama City， Mt. Nabekura， Sekita Pass， alt. 1100 m，

K. Inoue 010009 (SHIN sh 205211); K. Inoue 010006

(SHIN sh 205214); Chaya-ike， alt. 1100 m， K. Wada

012342 (SHIN sh 189762); Mt. Nabekura， Furu-ike，

alt. 1100 m， S. F吋isawas. n. (SHIN sh 183598); Mt.

Nabekura， Nishinosawa， alt. 1000 m， K. Otsuka 21953

Fig. 3. SympLocarpus nabekuraensis. A: Plant with fruits (26 Aug. 2001). B: Spadix with spathe (29 June

2001). C: Fruits (7 Aug. 2001). D: Fruits with peduncle (collected on 7 Aug. 2001). E: Spadix and

spathe (col1ected on 8 July 2001). A， B & C: At Sekita Pass， Mt. Nabekura (type locality). D， E:

Collected from type locality.

ハUQU

唱

EA 植物研究雑誌第77巻第2号 平成14年4月

(NAC); Niigata Pref.， Itakura Town，乱1t.Nabekura，

Sekita Pass， alt. 1100 m， K. Otsuka 21952 (NAC).

Perennials; rhizome ascending， with many roots of 2-3 mm thick. N ew shoot arising from rhizome， with several membraneous sheaths. Leaves radical， tufted， three to five，

with long petioles. Leaf blade reniform， en-tire， acute at apex， cordate at base， glabrous，

10-25 cm long， 20-40 cm broad; petioles 20-50 cm long; whole lengths of leaves are 30-70 cm. Spathes and leaves emerge simul-taneously， and flowers mature after develop-ment of leaves. Fruits mature in summer， and leaves wither in autumn. Spathes one or two in each individual， with long peduncle of 4-8 cm long; spathes dark pu叩lishbrown，

broadly ovate， acute， 4-7 cm long. Peduncle emerging from the ground; spathes erect when flowering and facing downward in

大塚孝ーヘ渡辺隆一九井上健C' 長野県で見い

だされたザゼンソウ属(サトイモ科)の 1新手重

長野県北部からザゼンソウ属の 1新種，ナベク

ラザ、ゼンソウ Symplocarpusnabekuraensis Otsuka &

K.lnoueを記載した.この種は葉身の形はザゼン

ソウに似るが，葉身や仏焔萄はず、っと小さい.仏

焔志の形や大きさはヒメザゼンソウに似て，仏焔

萄の先端は上を向くが，両者の葉形はかなり異な

り，ナベクラザゼンソウの葉身は腎円形で通常縦

fruiting stage as peduncle grow and curve ven佐ally.Flowers bisexual; perianths 4 ; an-thers 4; pollen grains yellow. Seed smooth on surface， and brownish， orbicular， about 2-10 mm in long diameter. Flowering season: Late June to early July. Habitat: 1n swamps under forests or in open bogs.

Nom. Jap.: Nabekura司 zazenso(nov.).

We thank H. N agamasu for his help on the comments to early draft of the manuscript， and M. Nakajima for prep紅 ingFigure 2.

References

Ohwi 1. 1978. F10ra of Japan. rev. ed， pp.1584.

Shibundo Ltd.， Tokyo (in Japanese). Ohashi H. 1982. Symplocarpus. In: Satake Y.， Ohwi J.，

Kitamura S.， Watari S. and Tominari T. (eds.)，

Wild flowers of Japan. Herbaceous plants 1: 138， pl.121. Heibonsha Ltd.， Tokyo (in Japanese).

よりも横の方が長い.ナベクラザゼンソウの植物

季節は上の 2種と異なり，花は葉が展開した後に

成熟し，果実は夏に熟し，葉は秋に枯れる特徴が

ある.

(a長野県自然保護研究所，

b信州大学教育学部，

b信州大学理学部生物科学科)