植物研究雑誌 THE JOURNAL OF JAPANESE BOTANY - … · —57— Asarum sect. Asiasarum Araki...

—57—

Asarum sect. Asiasarum Araki comprisessix species and three varieties and occurs innortheastern Asia: Japan, China, Korea, andeastern Russia (Maekawa 1936b, Cheng andYang 1983, Yamaki et al. 1996, Oh et al.1997, Lee and Lee 2000). In Japan, threespecies and one variety: A. sieboldii Miq., A.heterotropoides F. Schmidt var. hetero-tropoides, var. mandshuricum (Maxim.)Kitag., and A. dimidiatum F. Maek. havebeen recorded so far (Maekawa 1956, Ohwi1965, Satake and Momiyama 1982,Hatusima 1993). These taxa are classified

mainly by leaf characters (outline, especiallyapex shape, variegated or not, and pubes-cence in the abaxial surface and petiole),calyx lobe characters (apex shape, recurvedor erect), and the number of stamens andpistils.

In contrast, Nakamura (1986) appliedunique attributes to evaluate the variation ofsect. Asiasarum: floral, pollen, and chemicalcomponent characters rather than the foliarones. In floral characters, she adopted calyxtube characters: inner and outer color pat-tern, constriction at the throat, the number

植物研究雑誌J. Jpn. Bot.82: 57–78 (2007)

Originals

Morphological Comparison of Asarum sect. Asiasarum (Aristolochiaceae)in Japan with Special Reference to Multivariate Analyses of Flowers

Hiroki YAMAJIa, d, Teruko NAKAMURAb, Jun YOKOYAMAc, Kenji KONDOd,Takashi, MOROTAd, Shuichi TAKEDAd, Hiroshi SASAKId and Masayuki MAKIc

aBiological Institute, Graduate School of Science, Tohoku University,Aoba, Sendai, 980-8578 JAPAN;

bFaculty of Pharmaceutical Sciences, Tokyo University of Science,2641, Yamazaki, Noda, 278-8510 JAPAN;

cDivision of Ecology and Evolutionary Biology, Graduate School of Life Sciences,Tohoku University, Aoba, Sendai, 980-8578 JAPAN;

dResearch Division, Tsumura & Co., 3586, Yoshiwara, Ami, Ibaraki, 300-1192 JAPAN

(Recieved on October 24, 2006)

In order to clarify the morphological variation of plants belonging to Asarum sect.Asiasarum in Japan, we performed extensive field examinations for 55 populationscovering both geographic range, taxa, and morphological races hitherto recognized. Asprevious studies were not enough in evaluation of quantitative characters, we performedmultivariate analyses of various floral quantitative characters in addition to new qualita-tive floral characters, together with those used in the previous studies. As a result, eightmorphologically distinct forms were recognized. They were first divided into two groupsby color patterns in the inner surface of calyx tube; form D is dark purple, form L is darkpurple proximally, ivory white, yellowish green or light purple in the middle part, darkpurple or white at the throat. Form D is further divided into D1–D4 by the number ofcells of trichomes in the adaxial surface of calyx and by the number of stamens andpistils. Form L is further divided into L1–L4 by the shape of calyx tube, the width ofcalyx tube throat, and the size and shape of calyx lobes. The eight forms were distributedalmost allopatrically, and were concluded to be worthy to be recognized as distinct taxa.

Key words: Asarum sect. Asiasarum, color pattern, floral shape, multivariate analysis.

and distinctness of inner sculpture on innersurface, and the number of cells composingtrichomes on inner surface. As a result of herextensive survey in Japan, she divided A.sieboldii into five floral forms: “Aso type”,“Tanigawa type”, “San’in type”, “Tohokutype”, and “Western Honshu type” (Table 1).Each form has an almost disjunct distributionfrom the others. In characters of pollengrains, Nakamura (1986) and Nakamura andNagasawa (1987) reported the two forms ofthe supratecta corresponding to the floralforms. Type A pollen has smooth supratectaand is found in A. heterotropoides var.heterotropoides and the “Aso type”, “Tani-gawa type”, “San’in type”, and “Tohokutype” of A. sieboldii. Type B pollen hasstriated supratecta and is found in “WesternHonshu type” A. sieboldii and A. dimidia-tum. In chemical component characters, geo-graphic variations of phenylpropanoids andmonoterpenoids were examined for A.heterotropoides var. heterotropoides (Naka-mura et al. 1979), A. dimidiatum (Nakamuraet al. 1982), and A. sieboldii (Nagasawa1961, Nakamura et al. 1987). In A. sieboldii,the proportion of two phenylpropanoids(methyleugenol : safrole) had geographicallyclinal variations, and three distinct mono-terpenoid forms were recognized (Nakamuraet al. 1987). Floral, pollen, and chemicalcomponent characters almost correspondedto each other (Nakamura 1986). In conclu-sion, she recognized seven forms in Japan.

However, the study is insufficient in com-parison of quantitative characters, especiallythe size and shape of each part. For example,although “Tanigawa type” and “Tohokutype” A. sieboldii were discriminated by con-striction at throat of calyx tube and distinct-ness of longitudinal sculpture in innersurface of calyx tube, the delimitation ofthese characters between them were notpresented clearly. As the result, it is difficultto clarify plants into each form withoutgeographic information.

The aim of this study is to clarify the mor-phological variation of Asarum sect.Asiasarum in Japan. For the purpose, we per-formed extensive field examinations both ingeographic range and number of individuals.

To recognize distinct forms in quantitativecharacters, we newly applied one of the mul-tivariate analyses, canonical variates analysis(CVA). In cases where each of the examinedpopulations is highly expected to becomposed of individuals in a single group,CVA with each population as an a priorigroup makes it possible to know the bounda-ries between distinct groups without any apriori grouping by precedent systems (Wiley1991).

Materials and MethodsSamples examined

Field collections were performed on 55populations (Fig. 1, Table 2) in floweringseason from 1997 to 2001 to cover almost allareas where sect. Asiasarum plants were re-ported in Japan.

In field collections, ephemeral characterssuch as color patterns of calyx tubes wereobserved and color photographs were takenbefore fixing or pressing. Flowers were fixedwith FAA (formaldehyde: acetic acid: 50 �ethanol �1 : 1 : 18) and were then used forobservation and measurement. A number ofindividuals were cultivated. Voucher speci-mens are deposited in the Herbarium ofTohoku University (TUS).

Measurements and observations of floralattributes

Fourteen quantitative floral attributes weremeasured for 731 individuals from 55 popu-lations. More than half the characters are in-cluded in previous studies (calyx tube widthand length, calyx tube throat width, calyxlobe width and length, ovule position, pistilprotuberance width: Nakamura 1986,Yamaki et al. 1996: Fig. 2), and a part ofdata for A. heterotropoides var. hetero-

植物研究雑誌第82巻第2号平成19年4月58

Journal of Japanese Botany Vol. 82 No. 2April 2007 59T

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tropoides was quoted from Yamaji et al.(2006).

The procedure of measurement was same

as Yamaji et al. (2006). For vertical sectionsof flowers (Fig. 2A), flowers were cut longi-tudinally, and images of the sections were

Journal of Japanese Botany Vol. 82 No. 2April 2007 61

Fig. 1. Populations examined of Asarum sect. Asiasarum in this study.

Fig. 2. Measurement parts of flowers in Asarum sect. Asiasarum. A: Vertical section offlower, a: calyx tube length (CTL), b: calyx tube width (CTW), c: calyx throat width(CTTW), d: degree of calyx lobe (CLD), e: ovule position (e2/e1: OP). B: Flattened calyxlobe, f: calyx lobe length (CLL), g: calyx lobe width (CLW), h: calyx lobe foot width(CLFW), i: tip length (CLTL), j: tip degree (CLTD). C: Ridges in inner surface of calyxtube, k: height (RH), l: number (RN). D: Pistil, m: pistil protuberance length (PPL), n:pistil protuberance inclination (n1/n2: PPI).

digitized using a flat bed scanner (EPSONGT-7000S). Coordinates of 11 landmarkswere acquired from the digital images, andthe value of each character was calculatedfrom the coordinates. The same procedurewas used to characterize the calyx lobes (Fig.2B). Each calyx lobe was placed betweenglass slides, and its image was directly digit-ized by the flat bed scanner. The lengths ofpistils and the height of ridges on the innersurface of the calyx tube were measured witha fine plastic measure to 0.1 mm accuracy(Figs. 2C, 2D). Trichomes on inner surfaceof calyx tube and lobes were observed pre-liminary in a limited number of samplesusing a scanning electron microscope (SEM:Hitachi S-4100), and were subsequently con-firmed in the other samples using lightmicroscopes. For observation by the SEM,fixed flowers were dehydrated with ethanol/isoamyl acetate series, and were dried in acritical-point dryer (Hitachi HCP-1). Then,they were put on metal holders with adhesivetapes, and were coated with Pt-Pd (IonSputtering Machine: Hitachi E-1030). Theseprepared samples were observed by the SEMat 2–10kv. For observation by light micro-scope, fixed flowers were sliced by a freeze-microtome (Yamato Koki, KomatsuElectronic Inc. MA-101) were put on slideglasses with 50 � glycerol, and were sealedby cover glasses with a mounting reagent(Eukitt: O. Kindler).Data analysis

We aimed to establish a hypotheticalgrouping for the measured populations usingboth qualitative and quantitative characters.Canonical variates analysis (CVA) was per-formed with each population as an a priorigroup. The presumption of the CVA, uni-formity of each population, was decided byfield observations. The CVA was performedwith the computer program packageSTATISTICA 4.1J for Macintosh (StatsoftInc.) and SPSS 9.0 for Windows (SPSSJapan Inc.). The characters were standard-

ized manually by subtracting the total meanfrom an individual raw score and then divid-ing the difference by the total standard de-viation, so that each variable had a mean ofunity. To recognize discrete groups more ef-ficiently, the measured populations were alsodivided into several categories by diagnosticqualitative characters beforehand, and a newCVA was performed for each category.

After a hypothetical grouping was estab-lished, the grouping was compared with theother characters, to find available diagnositiccharacters.

ResultsCharacters other than floral quantitativecharacters

1. Habit In basic structure of plants be-longing to Asarum sect. Asiasarum in Japan,there is no difference in habit among theobserved materials in this study and thedescriptions by Maekawa (1936b) and Kelly(1997). They are low-growing, rhizomatousherbs with distinctive, modular growth.Flowering modules usually consist of almostfixed number of foliar organs: normally threescale leaves, two foliage leaves, and a soli-tary, terminal flower. Sterile modules consistof 2–3 scale leaves and one foliage leaf.Aberrant exceptions were recognized in afew individuals in populations Nos. 47 and54; they had three leaves in each module.Rhizome is hairless, about 5 mm in diameter,with leaf and flower trace and sometimesbranching. Roots are usually about 1 mm indiameter, fleshy, slender, distributed evenlyalong rhizomes. Cataphylls are caducous,glabrous, ciliate in the margin, triangularovate. Flower is solitary terminal, actinomor-phic. Peduncle is glabrous. Sepals are three,connate, forming calyx tube; calyx tube isglabrous in outer surface and striated longi-tudinally, internally ridged.

2. Foliage leaves Foliage leaves of thisgroup in Japan were almost similar: decidu-ous, membranous, alternate, and petiolate.


Laminae are simple, palmate veined, ciliatealong the margin. Proximal and distal lami-nae have different trend in outline: proximallamina ovato-cordate–broadly cordate, onthe other hand, distal lamina pentanguralovate cordate. They were highly variable insize even in a single population. In foliageleaves, Maekawa (1936b) recognized thatobtuse or acute (not acuminate) apex wascharacteristic of A. heterotropoides var.heterotropoides. However, we found manyintermediate forms in plants belonging thistaxon from southeastern Hokkaido (Yamajiet al. 2006) and northern Honshu (Nakamura1986).

All plants and specimens examined in thisstudy have laminae sparsely pilose on theadaxial surface and on the veins of abaxialsurface, and petioles are pilose in onlyadaxial ridges, though pubescens of leaf

laminae and petioles are used to discriminateplants belonging to this group in Korea andChina (Maekawa 1936b, Cheng and Yang1983, Yamaki et al. 1996). Consequently, itwas difficult for the plants to be divided intoseveral distinct states with such leaf charac-ters alone, and we compared the variation ofthem after a hypothetical grouping wasestablished with the other characters.

3. Position of hibernaculum There aretwo different forms in the position of thehibernaculum. In almost all cultivated indi-viduals from the populations examined, theaxillary bud of the most distal foliage leafdominantly developed into hibernaculum,and those of the proximal leaf and cataphyllssometimes develop secondarily. On the otherhand, in the individuals from two popula-tions in central Kyushu (Nos. 53, 54),axillary buds of cataphylls dominantly


Fig. 3. Variation of color pattern in inner surface of calyx tube in Asarum sect. Asiasarum. Bar �1cm. Form D. 1: population No. 47, 2: No. 43, 3: No. 51. form L. 4: No. 26, 5: No. 33, 6: No.19, 7: No. 53.

developed instead and those of foliage leavesdid not develop. This difference probably af-fects the shape of rhizomes; the former tendsto grow straight, the latter tends to grow zig-zag.

4. Floral color pattern In color patternsof internal surface of calyx tube, two distinctforms, we call forms D and L hereafter, wereobserved (Fig. 3). The pattern of form D wasas follows: ivory white or greenish yellow atthe base, dark purple proximally, in the mid-dle part, and at the throat. The pattern ofform L was as follows: ivory white or green-ish yellow at the base, dark purple proxi-mally, ivory white, yellowish green, lightpurple, or their intermediate in the middlepart, dark purple or rarely ivory white at thethroat. Ivory white throat were recognized in

all the individuals of Nos. 53 and 54, andrarely in Hokkaido populations. Therefore,the two forms were clearly distinct in themiddle part: dark purple or not. These colorpatterns were stable within a single popula-tion.

The distribution of the two forms werealmost allopatric (Fig. 4A). Form D was dis-tributed in central and western Honshu,Shikoku, and Kyushu. Form L was distrib-uted in Hokkaido, northern and easternHonshu, and disjunctively in central Kyushu.The border of the two forms in Honshu laynear the 37°00´N parallel.

In contrast, the color of outer surface ofthe calyx tube varied even in a single popula-tion. Nevertheless, four distribution patternwere recognized: (1) bright dark purple,


Fig. 4. Geographic variation of Asarum sect. Asiasarum in Japan. A: Color pattern of flower. B:Number of cells of each multicelluar hair in adaxial surface of calyx tube and lobes.

mainly in Hokkaido, (2) bright ivory pink,light purple, or their intermediates, in centralKyushu and northern Honshu, (3) yellowishbrown with purple dots, olive green withpurple dots, purple with yellowish greendots, or their intermediates, in central andnorthern Honshu, (4) grayish olive greenwith purple dots, in central and westernHonshu, Shikoku, and Kyushu. The colorpattern combinations of adaxial and abaxialsurface of calyx lobes also varied even in asingle population. The abaxial surface wasgenerally the same as or brighter coloredthan that of outer surface of calyx tube.However, the color of the adaxial surfaceseemed to have no relation to that of theabaxial surface and varied from ivory pink,dark purple to light green, or intermediatecolors.

Individuals in the greater part of the popu-lations had pistil protuberances colored darkpurple to greater or less degrees. On theother hand, populations in central Kyushu(Nos. 53, 54), and almost all individuals in apopulation in western Honshu (No. 48) wereunique in having yellowish green protuber-ances.

5. Trichomes of flowers The number ofcells in each trichome on the inner surface ofthe calyx tube and adaxial surface of calyxlobes varied remarkably among the popula-tions but was stable within a single popula-tion. In the precedent studies, this characterwas simply categorized into four forms; eachtrichome was composed of (1) single, (2)three, (3) five, or (4) seven to ten cells(Nakamura 1979, 1986, Table 1). However,the result in this study was rather variable;the number of cells of trichomes sometimesdiffered about �one even within an individ-ual. Consequently we divided trichome con-ditions into four forms (Fig. 5). The numberof cells in each form was as follows: one ortwo (form H1), three to five (rarely morethan five, form H2), six or seven (rarelyeight, form H3), and seven to ten (sometimes

more than ten, form H4). The distribution ofeach form was less allopatric than that of thecolor pattern in the inner surface of calyxtube (Fig. 4B); form H1 was observed ineight populations from central Honshu, formH2 was in 40 populations from almost allareas examined, form H3 was in six popula-tions in narrow area of central Honshu,northeastern Honshu, and Hokkaido, andform H4 was in only one population in west-ern Honshu (No. 48).

6. The number of stamens and pistilsAs in the other sections of Asarum, the regu-lar number of stamens and pistils were 12and 6, respectively, and the greater part ofpopulations examined showed these standardnumbers: standard S (stamens) & P (pistils).On the other hand, in three populations (Nos.50, 51, and 52), they are reduced to half: 6and 3, respectively: reduced S & P. Reduc-tion of stamens and pistils is regarded as oneof the diagnostic characters to discriminateA. dimidiatum from the other species(Maekawa 1936a, 1936b, Ohwi 1965, Satakeand Momiyama 1982).

7. Conclusion of the characters otherthan floral quantitative traits Among thecharacters mentioned above, the floral colorpattern in inner surface of calyx tube wasmost discrete and stable, and the two formswere distributed in different areas. Thereforewe classified populations into forms D and Lfirstly, and further subdivided them by theother characters, and compared with CVAresults.

Form D populations involved a widerrange of variation than form L populations inthe qualitative characters examined in thisstudy. In the condition of trichomes of flow-ers, form D populations were divided intothree forms, form H1 (eight populations),form H2 (eight populations), and form H4(one population). In the number of stamensand pistils, fourteen populations had standardS & P, and three populations had reduced S& P. In the combination of these two


characters, four forms were recognized inform D populations: form D1 (form H1,standard S & P, eight populations), form D2(form H2, standard S & P, five populations),form D3 (form H4, standard S & P, onepopulation), and form D4 (form H2, reducedS & P, three populations). The four D formswere almost allopatrically distributed (Fig.6). Form D1 was distributed in centralHonshu, form D2 was in western Honshu,form D3 was restricted to western Honshu,and form D4 was in Shikoku and Kyushu.

Form L populations were less variable inthe characters examined above. Though theyare divided into two forms, form H2 (32populations) and H3 (six populations), in thecondition of trichomes, the distribution andrelationship to the other characters were lessclear. Moreover, the other characters are dif-

ficult to classify the form L populations intomore than one distinct group.

Canonical variates analyses (CVA) forfloral quantitative characters

Through the field observations, we foundthat each population was most likely com-posed of only a single morphological formbecause the shape, the proportions of vari-ables, and most of the qualitative charactersof flowers mentioned above were stable ineach population (Yamaji unpubl. data). Thiscondition enabled us to designate each popu-lation as an a priori group for CVA (Wiley1991).

1. Total populations Fourteen signifi-cant (p < 0.00001) CVs were calculated. Thevariances accounted for the axes I–III were45, 22, and 8 �, respectively. The eigen-


Fig. 5. SEM phtographs of hairs on inner surface of calyx lobe in Asarum sect. Asiasarum. A: Form H1(population No. 39). B: Form H2 (No. 24). C: Form H3 (No. 38). D: Form H4 (No. 48). Bar �100 µm.

vectors of each variable to CV I, CV II, andCV III are shown in Table 3A. The two-dimensional scatter diagrams on CV I & IIand CV I & III are shown in Figs. 7A and7B, respectively. The ranges of populationsoverlapped with each other, and any clusterswere hardly recognized in the diagrams. Thisunclear result may indicate the limit of CVAfor simultaneous recognition of many

groups. Therefore, as elucidated above, com-bined analyses with the other charactersexamined above possibly act effectively todiscriminate morphologically distinctgroups.

The most clear-cut quantitative character,color pattern in inner surface of calyx tube(forms D and L) divided both the individualsand populations into different ranges effec-


Fig. 6. Recognized forms of Asarum sect. Asiasarum in Japan in combination with color form, hairform and the CVA results.

Table 3. The standardized eigenvector and eigenvalues for the first three caronical variables in Asarum plants ex-amined in this study

A. Total populations B. Color form D populations C. Color form L populations

VariablesAxes Axes Axes

I II III I II III I II III

Ovule position (OP)Calyx tube width (CTW)Calyx tube length (CTL)Calyx tube throat width (CTTW)Degree of calyx lobe (CLD)Calyx lobe length (CLL)Calyx lobe width (CLW)Calyx lobe foot width (CLFW)Tip degree (CLTD)Tip length (CLTL)Pistil protuberance length (PPL)Pistil protuberance inclination (PPI)Calyx tube ridges height (RH)Calyx tube ridges number (RN)

EigenvaluesPercentage of total variance

0.300–0.824–0.1410.6420.2770.1810.4720.159

–0.0750.0320.1600.151

–0.3760.310

16.25644.9 �

0.2770.154

–0.7810.160

–0.3070.073

–0.4490.106

–0.016–0.0020.465

–0.0740.729

–0.075

7.77821.5 �

0.2770.6640.101

–0.283–0.400–0.479–0.0250.6410.1900.048

–0.2540.328

–0.1410.056

3.0568.4 �

–0.434–0.2120.474

–0.5730.007

–0.8350.510

–0.151–0.079–0.017–0.1950.0050.855

–0.037

11.18534.4 �

0.023–0.677–0.7130.3560.139

–0.4160.0600.028

–0.0480.0160.644

–0.3070.7650.216

8.08524.9 �

–0.273–0.3020.1450.1330.3780.724

–0.471–0.049–0.127–0.213–0.125–0.476–0.425–0.517

5.31316.4 �

–0.0180.747

–0.382–0.444–0.515–0.177–0.342–0.1520.113

–0.0120.013

–0.0820.647

–0.374

12.70347.6 �

–0.346–0.1600.352

–0.3150.2510.1670.447

–0.811–0.050–0.008–0.2780.030

–0.023–0.147

5.28519.8 �

0.0040.0860.556

–0.083–0.188–0.314–0.3430.5030.122

–0.104–0.4310.433

–0.345–0.335

2.6529.9 �


Fig.

7.T

wo-

dim

ensi

onal

scat

ter

ofth

esa

mpl

esof

Asa

rum

sect

.A

sias

arum

onca

noni

cal

vari

ate

axes

.A

:A

llpo

pula

tions

,C

VI

&C

VII

.B

:A

llpo

pula

tions

,C

VI

&C

VII

I.In

divi

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sin

Aan

dB

are

dist

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).

tively in the CV I & CV II scatter diagram(Fig. 7A). Form D individuals mainly occu-pied in positive field in both of the two CVsexcept one population (No. 48, as mentionedabove, the unique population with form H4hairs), and form L ones occupied in the otherfield. This result indicates that individualsdifferent in floral color pattern are also dif-ferent in the shape and/or size.

2. Color form D populations Ten sig-nificant (p < 0.00001) CVs were calculated.The variances accounted for the axes I–IIIwere 34, 26, and 16 �, respectively. Theeigenvectors of each variable to CV I, CV II,and CV III are shown in Table 3B.

In the two-dimensional scatter diagram onCV I and CV II (Fig. 7C), any clusters werehardly recognized. This result possibly indi-cated that there is no clear border to divideform D populations into more than onegroup in floral quantitative variation alone.In the diagram, most form D1 populationswere in negative field to around neutral posi-tion in the both axes, on the other hand, formD2 populations were around neutral positionto positive field in both axes. Form D3 popu-lation was in the positive field in CV I andnegative field in CV II. Form D4 populationswere around neutral position of CV I andaround neutral position to positive field ofCV II, and overlapped with both forms D1and D2. Among the coefficients of CV I,highly negative factors were seen in charac-ters CLL, CTTW, and OP, on the other hand,highly positive factors were in RH, CTW,and CTL. As well, among the coefficients ofCV II, highly negative factors were in CTL,CLW, CLL, and PPI, and highly positivefactors were in RH, PPL, and CTTW.

In the two-dimensional scatter diagram onCV II and CV III (Fig. 7D), which waseffective to make clusters between the popu-lations, it should be noted that form D3 wasseparated in the positive field in CV II and inthe negative field in CV III. Among the coef-ficients of CV III, highly negative factors

were seen in characters CTW, CLW, PPI,RH, and RN, and highly positive factorswere in CLD and CLL. The difference ofdistribution range of each form in the scatterdiagrams indicates that the four forms werecontinuous but different in the floral quanti-tative characters, which supports the differ-ence in morphological variation of amongform D populations.

3. Color form L populations Elevensignificant (p < 0.00001) CVs were calcu-lated. The variances accounted for the axesI–III were 48, 20, and 10 �, respectively.The eigenvectors of each variable to CV I,CV II, and CV III are shown in Table 3C.

The two-dimensional scatter diagram onCV I & CV II is shown in Fig. 7E. In thescatter diagram, four clusters were recog-nized. The result of comparatively clear clus-ters was different from that in form Dpopulations; the overlap area between thepopulations was remarkably larger than thatof form D.

Three clusters were recognized along theaxis CV I. The first cluster (form L1) in thepositive field was composed of 24 popula-tions. The second cluster (form L2) in thenegative field was composed of six popula-tions. The third cluster (form L3) was in theintermediate position between the first andthe second clusters, and was composed ofthree populations. Though the three clustersoverlapped in their margins, a few aberrantexceptional individuals seemed to causethese overlaps. In addition, their medianpoints were obviously in different positions.Therefore, we decided that they are enoughto be hypothetical distinct forms for the firststep of the following analyses. Among thecoefficients of CV I, highly negative factorswere seen in characters CLD, CTTW, CTL,RN, and CLW, and highly positive factorswere in CTW and RH.

Two populations in central Kyushu (Nos.53, 54) were separated in the negative fieldof CV II from the other populations, and



Fig.

7.C

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C:

Form

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I&

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Fig.

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range of these two populations strongly over-lapped each other; we call them form L4.Among the coefficients of CV II, highlynegative factors were seen in charactersCLFW, CTTW, and PPL, and highly posi-tive factors were in CLW, CTL, and CLD.

The two-dimensional scatter diagram onCV I and CV III, which was effective tomake clusters between the populations, isshown in Fig. 7F. In this diagram, form L4was completely immerged into the range ofform L1, while form L2 and L3 occupieddifferent range in CV III. Among the coeffi-cients of CV III, highly negative factors wereseen in characters PPL, RH, CLW, RN, andCLL, highly positive factors were in CTL,CLFW, and PPI.

These four forms could be recognizedmore conspicuously by the combination ofother qualitative characters mentionedabove. In the position of hibernaculum, thoseof form L4 were dominantly in axillary budsof cataphylls, on the other hand, those of theother forms were dominantly in axillary budsof distalmost foliage leaf. In trichomes offlowers, two forms were observed in L forms(Figs. 7E, 7F). All populations belonging toform L3 and six of 24 populations belongingto form L1 had form H3 trichomes. Theother populations had form H2 trichomes.Although form L3 was overlapped with formL1 and L2 in the margin in the scattereddiagram of CV I and CV II, it could be dis-tinguished from at least form L2 in this char-acter.

The four forms had slightly differingshape in foliage leaves especially at theirapex. Form L4 stably had obtuse or acuteleaves at apex, and forms L2 and L3 stablyhad leaves at the acuminate apex. On theother hand, form L1 had various leaves inapical shape; individuals in northern Honshuand southeastern Hokkaido tended to haveacuminate leaves at apex, but the other indi-viduals tended to have leaves obtuse or acuteat the apex. The stability of leaf forms also

varied among populations.In the color of calyx lobes and outer sur-

face of the calyx tube, the four forms haddifferent trends. Calyx tubes and lobes ofform L4 individuals were ivory pink, lightpurple, or their intermediate colors withoutany mixture of desaturated colors, e. g., olivegreen. Those of form L1 were roughlydivided into three forms recognized in differ-ent areas: (1) fine ivory pink, light purple, ortheir intermediate colors found in northernHonshu, (2) desaturated olive green withpurple dots, purple with yellowish greendots, or their intermediate colors, calyx lobessometimes light green found in southeasternHokkaido, (3) uniformly fine dark purpleseen in almost all area of Hokkaido.However, they were continuous with inter-mediate individuals. Those of forms L2 andL3 were variable even in one population,yellowish brown with purple dots, olivegreen with purple dots, purple withyellowish green dots, or their intermediatecolors. Calyx lobes of form L3 were some-times pale green.

Univariate analysesThe eight forms recognized in the qualita-

tive characters and the CVAs were comparedin each floral quantitative character or ratioof several characters to examine their dis-creteness among the forms, and to find diag-nostic characters between them.

1. Size and shape of calyx tube (CTL,CTW, CTTW, and OP) In CTL andCTW, which represent the size of calyx tube,the ranges of form D4 were conspicuouslylower than those of the other forms, andwere almost discontinuous especially withthe other D forms (Figs. 8A, 8B). In CTLform D3 was conspicuously higher than theother D forms, and that of L4 was lower thanthe other L forms, especially almost discon-tinuous with form L2 (Fig. 8A). In CTW,form L4 was larger than the other L forms(Fig. 8B). In ratio CTL/CTW (Fig. 8C), the


range of form D3 was almost disconti-nuously higher than those of the other Dforms, and that of form L4 was almost dis-continuously lower than the other L forms.Those of L forms except form L4 weregenerally higher than those of D formsexcept form D3.

In the range of CTTW, the eight formswere divided into two groups; those of form,D1, D2, D4, L4, and L2 were larger, andthose of forms D3, L1, and L3 were smaller(Fig. 8D). The range of ratio CTTW/CTWdivided the two groups more effectively,nearly discontinuously with value 0.55 asboundary (Fig. 8E).

In OP, which represents ovule position,the range of form L3 was lower than those ofthe other forms, and was almost discontinu-ous with those of all D forms and form L4(Fig. 8F).

2. Size and shape of calyx lobe (CLD,CLL, CLW, CLFW, CLTL, and CLTD)In CLD (Fig. 8G), which represents the con-dition of calyx lobes, e.g. recurved, patent, orerect, the range of D forms were wider thanthose of L forms and highly overlapped eachother within D forms. On the other hand, Lforms were divided into two groups; those ofform L4 and L1 were lower, and those ofform L2 and L3 were higher. It should benoted that the range of form L1 was broaderthan those of the other L forms, from highlyrecurved to patent. These results indicate thatthe condition of calyx lobes is not alwaysstable though Maekawa (1936b), Ohwi(1956), and Satake and Momiyama (1982)applied it to discriminate A. heterotropoidesfrom A. sieboldii.

CLL, CLW, and CLFW represent the sizeof calyx lobes. In CLL, the range of form L4and L1 were lower than those of the otherforms, almost discontinuous with form L3(Fig. 8H). In CLW, form L1 had lower rangethan the other L forms (Fig. 8I). In CLFW,the range of form D3, L1, and L3 were lowerthan those of the other forms (Fig. 8J); such

trends were similar to those of CTTW/CTW(Fig. 8E). In ratio CLL/CLW, which repre-sents the aspect ratio of calyx lobes, therange of form L4 was almost distinctlylower, and that of form D3 was almost dis-continuously higher than those of the otherforms (Fig. 8K). The range of CLFW/CLW,which represents the degree from pentangu-lar to deltoid in outline of calyx lobe,showed that form L4 had deltoid calyx lobesthough the other forms had pentangular ones,and that form L3 was almost distinct fromthe other L forms in calyx lobe shape (Fig.8L).

Almost all individuals of form L4, andmany individuals of form L1 had no or littlepart corresponding to CLTL, which repre-sents the degree of tapering (obtuse toacuminate) in calyx lobes at apex (Fig. 8M).On the other hand, almost all individuals inthe other forms had this part. Although api-cal shape of calyx lobes is one of thediscriminant characters between A. sieboldiiand A. heterotropoides var. heterotropoides(Schmidt 1868, Maekawa 1936b, Ohwi1956, Satake and Momiyama 1982), consid-erable numbers of samples in Hokkaidobelonging to A. heterotropoides var.heterotropoides had acuminate calyx lobeswith acuminate apices (Yamaji et al. 2006).

In CLTD, the range of form D3 was lowerbut overlapped than those of the other forms,and that of form L4 was almost discontinu-ously higher than those of the other forms(Fig. 8N).

3. Pistil characters (PPL and PPI) PPL(Fig. 8O) was adopted for one of thediscriminant characters for sect. Asiasarumplants in Korea (Yamaki et al. 1996). Theranges of PPL of L forms, excluding formL4 were lower than those of D forms excludeform D3. The range of form L4 was higherthan those of the other L forms, and wasalmost discontinuous with that of form L2.The ranges of PPI were, however, highlyoverlapped among the all forms (Fig. 8P).



Fig.

8.B

oxan

dw

hisk

erpl

otfo

rea

chqu

antit

ativ

ech

arac

ter

orpr

opor

tions

inth

eei

ght

form

sof

Asa

rum

sect

.A

sias

arum

reco

gniz

edin

this

stud

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omth

ele

ftto

righ

t,fo

rmD

1,D

2,D

3,D

4,L

1,L

2,L

3,an

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4.


Fig.

8.C

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ued.


Fig.

9.C

ompa

riso

nbe

twee

nfr

esh

flow

ers

for

the

eigh

tfor

ms

ofA

saru

mse

ct.A

sias

arum

plan

tsre

cogn

ized

inth

isst

udy.

Form

D1

(No.

41),

D2

(No.

50),

D3

(No.

49),

D4

(No.

51),

L1

(No.

15),

L2

(No.

35).

L3

(No.

33),

and

L4

(No.

54).

4. Ridges in inner surface of calyx tube(RH and RN) In RH, the ranges of theeight forms were different from each other(Fig. 8Q). It is noteworthy that those of formD1 and D2 were markedly different, thoughthere were little conspicuous differences inthe other quantitative characters. In particu-lar, that of form L2 was almost discontinu-ously lower than those of the other L forms.In RN (Fig. 8R), the range of form D3 waslowest among those of all the eight formsand almost discontinuous with those of theother forms except forms D4 and L1, andthat of form L4 was higher than those of theother forms and almost discontinuous withthose of forms D3 and L1.

DiscussionIn this study, we recognized the eight

morphologically distinct forms belonging toAsarum sect. Asiasarum in Japan (Fig. 9).Their distributions were almost allopatric(Fig. 6). Form D1 was recognized in centralHonshu; form D2 was from the west ofcentral Honshu, form D3 was in a restrictedarea of western Honshu, and form D4 was inShikoku and Kyushu. Form L1 was recog-nized in Hokkaido, northern Honshu, formL2 was in north of central Honshu, form L3was in restricted area of central Honshu, andform L4 was in restricted area of centralKyushu. Although a few intermediate indi-viduals were exceptionally recognized in theCVAs, we conclude that the all eight formsare worthy to put distinct taxa.

Fourteen of 55 populations used for thedetailed observation of floral characters werealso examined in the previous studies(Nakamura et al. 1979, 1987, Nakamura1986, Nakamura and Nagasawa 1987, Table2), and those populations covered all taxarecognized by Nakamura (1986). As theresult of comparison in these populations,each form corresponded to only the singleform in Nakamura (1986): forms D1 andD2 �“Western Honshu type” A. sieboldii,

D3 �“San’in type” A. sieboldii, D4 �A.dimidiatum, L1 �A. heterotropoides var.heterotropoides, L2 �“Tohoku type” A.sieboldii, L3 �“Tanigawa type” A. sieboldii,and L4 �“Aso type” A. sieboldii. There is nodiscrepancy except that “Western Honshutype” A. sieboldii separated into form D1 andD2. Nakamura (1986) noted that “WesternHonshu type” A. sieboldii with multicellulartrichomes of flower, which is the diagnosticcharacter of form D2, were exceptionalbecause they were recognized in only a fewpopulations, however, form D2 is commonlydistributed in the west of central Honshu.

This study investigated the effectivenessof detailed measurements of quantitativecharacters and multivariate analyses for clas-sification of plants. Like sect. Asiasarum, incase of a group of plants which is difficult toclassify by single or a few quantitative char-acters, e. g., size, shape, and ratio of twocharacters, multivariate analysis is able todiscriminate more than one forms by theirdifferences in their general shape. In thisstudy, one of the multivariate analyses,canonical variates analysis (CVA; Wiley1991) proved effective at discriminating offour forms in forms L.

The authors are grateful to Dr. H. Ohashiof Tohoku University, Dr. J. Endo of ScienceUniversity of Tokyo, Dr. Y. Kadota ofNational Museum of Nature and Science, Dr.T. Nemoto of Ishinomaki Senshu University,Dr. T. Fukuda of Kochi University for theirsuggestions and advices in the course of thisstudy. Thanks are also due to Dr. H. Nakai,Messrs. M. Tanaka, M. Sumita, Y. Mizunoand many people in Samani, Hokkaido, forfacilities of field works by the first authors inHokkaido, and Dr. H. Kohda, Messers. R.Toya, N. Kumagaya, S. Inoue for the samplecollection in the other area.

References

Cheng C. Y. and Yang C. S. 1983. A synopsis of the


Chinese species of Asarum (Aristolochiaceae). J.Arn. Arb. 64: 565–597.

Hatusima S. 1993. Asarum heterotropoides var.mandshuricum newly found in Japan. J.Phytogeogr. Taxon 41: 69–70.

Kelly L. M. 1997. A cladistic analysis of Asarum(Aristolochiaceae) and implications for the evolu-tion of herkogamy. Amer. J. Bot. 84: 1752–1765.

Lee Y. N. and Lee J. Y. 2000. Asarum in Korea. Bull.Korea Pl. Res. 1: 16–30.

Maekawa F. 1936a. Japanese Asaraceae (IX). J. Jpn.Bot. 12: 28–35.

1936b. Aristolochiaceae. In: Nakai T. (ed.), FloraSylvatica Koreana 21: 1–28.

1956. Phylogeny of plants. Shizen 11: 12–20 (inJapanese).

Nagasawa M. 1961. Analysis of crude drugs by infra-red spectrophotometry II. Analysis of radixAsiasari by infrared spectrophotometry. YakugakuZasshi 81: 129–138 (in Japanese).

Nakamura T. 1979. Geographic variation of Asiasarumsieboldii (Miq.) F. Maek. Shuseibutsugaku-kenkyu3: 70–77 (in Japanese).

1986. Taxonomical studies of JapaneseAsiasarum (Aristolochiaceae) with special refer-ence to geographical variation in the morphologyand chemical composition. Dr. thesis. TokyoMetropolitan University.

and Nagasawa M. 1987. Variation in pollengrains of Japanese Asiasarum (Aristolochiaceae). J.Jpn. Bot. 62: 134–138., Endo J. and Hamada T. 1982. Variation of

Asiasarum dimidiatum. J. Jpn. Bot. 57: 366–375 (inJapanese).

, and Nagasawa M. 1979. Geographicalvariation of the essential oil components inAsiasarum heterotropoides. J. Jpn. Bot. 54: 334–341., and 1987. Geographical variation in

essential oil composition of Asiasarum sieboldii(Aristolochioaceae). J. Jpn. Bot. 62: 7–16.

Oh B., Nam O. and Kim J. 1997. A new species ofAsarum sect. Asiasarum from Korea: A. misandrumB. Oh et J. Kim. Kor. J. Plant Tax. 27: 491–499.

Ohwi J. 1965. Flora of Japan (in English ; Meyer, F. G.and Walker, E. H. (eds.) ). Smithsonian Institution,Washington, D. C.

Satake Y. and Momiyama S. 1982. Aristolochiaceae.In: Satake Y. et al. (eds.), Wild Flowers of Japan,Herbaceous plants. II: 102–109. Heibonsha, Tokyo(in Japanese).

Schmidt F. 1868. Reisen im Amur-Lande und auf derInsel Sachalin, p.171. Mémoires de l’AcadémieImpériale des Scienses de St.-Pétersbourg, VIISerie. Tome XII, No. 2.

Wiley E. O. 1991. Phylogenetics–The theory and prac-tice of phylogenetic systematics (Japanese edition:Miya M., Nishida S. and Okiyama M. translated).Tokyo: Bunichi-sogoshuppan.

Yamaji H., Yokoyama J., Ohashi H. and Maki M.2006. Concordant clines and significant correlationbetween floral and pollen characters in Asarumheterotropoides var. heterotropoides (Aristolochia-ceae). Pl. Syst. Evol. 259: 1–17.

Yamaki K., Terabayashi S., Okada M. and Pak J.-H.1996. A new species and new variety of Asiasarum(Aristolochiaceae) from Korea. J. Jpn. Bot. 71: 1–10.


山路弘樹a, d, 中村輝子b, 横山潤c, 近藤健児d,諸田隆d, 竹田秀一d, 佐々木博d, 牧雅之c：花部形態の多変量解析に基づく日本産カンアオイ属ウスバサイシン節の形態比較日本産カンアオイ属ウスバサイシン節植物の形態変異を明らかにするために, 国内の全分布域・既知の分類群, 地域集団を含む55集団について野外調査を行った. 同節に関する過去の研究はいずれも量的形質の評価が不十分であるため, 本研究では今まで用いられてきた形質, 新たに採用した形質の評価に加え, 花の量的形質に基づく多変量解析を行った. その結果, 形態より区別できる 8型が認識された. 日本の同節はまず萼筒内壁のカラーパターンで 2型に分けられ, D型は全面暗紫色なのに対し, L型は基底部は暗紫色, 中央部は

黄緑色ないし淡紫色, 萼筒開口部は暗紫色ないし白色だった. D型はさらに萼筒内壁, 萼裂片内面の毛の細胞数, 雄蕊・雌蕊の数で D1–D4の 4型に分けられ, L型は萼筒の形態, 萼筒開口部の大きさ, 萼裂片の形態, サイズで L1–L4の 4型に分けられた. この 8型はほぼ異所的に分布し, それぞれ独立の分類群に値するまとまった地域集団と推定された.

(a東北大学大学院理学研究科生物学教室,b東京理科大学薬学部,

c東北大学大学院生命科学研究科,d株式会社ツムラ中央研究所)

植物研究雑誌 THE JOURNAL OF JAPANESE BOTANY - … · —57— Asarum sect. Asiasarum Araki...

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