8/11/2019 Ewers Et Al-1990

1/9

8/11/2019 Ewers Et Al-1990

2/9

545

Table 1. Survey of vessel dimensions. For habit, SC = scrambler, SC/TEN = scrambling habit with occasional branch tendrils, SH = shrub,TEN = tendril climber, TR = tree, TW = twiner. For method, A = air, P = paint

Taxon Habit Method Xylem Vessel diameter (gm) Vessel length (cm)diameter(mm) rain ~ Median max ~ Media n max

Dicotyledons

Annonaceae

Bhandari

Artabotrys hexapetalus (L. f.) SC P 10 13 34 26 90 5 3 27

Aristolochiaceae

Aristolochia gigantea Ma rt . & Zucc. TW A 4.5 4 23 12 219 171A. maxima Jac q. TW A 8.5 13 116 109 306 189A. veraguensis Duc har tre TW A 7 19 108 42 307 260

Bignoniaceae

Anemopaegmapuberulum (Sieb.) Mir and a TEN P 9 10 50 29 186 26 25 115Arrabidaea corallina (Jaeq.) Sandw.

st em I TE N A 6 10 28 18 143 186st em 2 TE N P 11 13 36 22 214 69 60 250

A. podopogon DC) A. Gentryst em 1 TE N A 8.5 6 24 13 194 55 39 154ste m 2 TE N A 9 8 35 18 159 67 63 167

Macfadyena Doxantha) unguis-cati(L.) A. Gentry

st em 1 TE N A 1.2 5 22 13 81 19 13 94st em 2 TE N A 2 6 21 19 71 79 25 255st em 3 TE N A 2.5 4 24 13 93 133stem 4 TE N A 2.5 123

Mansoa allicea A. Gen try TE N A 9 5 22 14 126 84M. verrucifera (Schlech t.) A. Gen try TE N A 18 10 58 56 134 46 38 126Pithecoctenium crueigerum (L.) A. Gentry

st em 1 TE N P 2.5 9 37 13 98 32 25 150 ast em 2 TE N P 2.5 6 30 18 105 42 25 170 bst em 3 TE N A 5 8 44 17 217 69 25 375st em 4 TE N P 14 10 75 27 381 ]08 25 5 5 bst em 5 TE N A 19 11 74 26 360 112 25 773st em 6 TE N P 25.5 141 125 6258

Pyrostegia venusta (Ker -Gaw l.) Mier s TE N A 9 12 39 21 233 153Saritaea magnifica Dug.

ste m 1 TE N P 6 6 30 23 118 5 4 21ste m 2 TE N A 14 13 56 45 157 55 37 270

Combretaceae

Combretum paniculatum Venten.st em i SC A 10 13 49 26 380 199st em 2 SC A 12 170

Convolvulaceae

Argyreia nervosa (Bu rm. f.) Boj er TW A 12 16 64 29 401 57 62 131

FabaceaeBauhinia aculeata L.

ste m 1 SH A 5.5 8 27 25 75 3 3 34ste m 2 SH P 6 9 31 18 92 5 3 47

B. blakeana Dunn.st em 1 TR A 11 13 48 38 115 10 5 83st em 2 TR P 11.5 9 51 47 117 30 35 85st em 3 TR P 11.5 9 57 60 113 29 25 75st em 4 TR A 16.5 13 55 44 132 15 10 100

B. corymbosa Roxb. ex DCst em 1 TE N P 3 8 29 16 146 7 5 55st em 2 TE N P 3 6 20 12 124 13 5 55st em 3 TE N A 4 6 20 14 182 184stem 4 TE N A 4.5 157

8/11/2019 Ewers Et Al-1990

3/9

546

Table 1 (continued)

Taxon Habit Method Xylemdiameter(mm)

Vessel diameter (gm)

rain ~ Median

Vessel length (cm)

max f~ Med ian max

B fassoglensisKotschy ex Schweinf.stem 1stem 2stem 3stem 4stem 5

B galpiniiN.E. Brstem 1stem 2stem 3

B purpurea Lstem 1stem 2stem 3stem 4

B vahliiWight & Arn.stem 1stem 2stem 3

B variegata LDalbergia brownei(Jacq.) Benth.Derris scandens(Roxb.) Benth-

Hippocrateaceae

Hippoeratea volubilis Lstem 1stem 2

Malpighiaceae

Maseagnia psilophylla(Juss.) Griseb.stem 1stem 2

Peixotoa glabraJuss.

stem 1stem 2Stigrnaphylloncf. periploeifoliumJuss.S ellipticum(HBK) Juss.

stem 1stem 2stem 3

Nyctaginaceae

Bougainvillea spectabilisWilld.stem 1stern 2

Passifloraceae

Passiflora eoceineaAubl.stem 1stem 2stem 3

Polygonaceae

Antigonon leptopusHook. & Arn.

Sapindaceae

Serjania polyphy lla(L.) Radlk.stem 1stem 2stem 3

TENTENTENTENTEN

SHSHSH

TRTRTRTR

TENTENTENTRSC/TENTW

SC/TENSC/TEN

TWTW

TWTWTW

TWTWTW

SCSC

TENTENTEN

TW

TENTENTEN

APPAA

APA

APPA

AAAAPP

PP

AA

PAA

APA

AA

APA

A

AAP

33333.5

3.53.5

20

779

13

79

111212

6

46

6.57.5

4.578

447

11.511.5

13.5

7

34.56

10 24 1810 37 22

6 42 296 23 14

8 39 277 33 22

12 49 38

10 30 209 40 36

13 41 3913 42 26

7 51 436 24 179 43 25

10 48 389 48 394 14 10

10 42 279 66 56

10 29 20

10 34 199 21 158 23 16

8 25 156 20 146 33 21

7 27 21

4 26 137 34 204 17 12

6 27 14

4 13 10

10 37 18

210 27 10 65215 11 5 65233 9 5 45213 23 5 73

270

99 7 5 44 a91 9 5 55 a

134 7 5 71

88 17 10 48 a109 8 5 65 a91 9 5 55

103 15 5 77

185 17 10 81226 37 30 110211 26 13 117144 11 10 101133 12 5 55189 37 30 150

161 30 20 100193 38 20 220

122+176 100

228 23 10 130181 168212 151

208 43 37 160 a207 27 12 87 a222 194

32107 43

128 16 5 52 a87 10 5 45 a

249 179

233 86

156 143112

257 75 60 220

8/11/2019 Ewers Et Al-1990

4/9

8/11/2019 Ewers Et Al-1990

5/9

548

mum lengths determined for each stem. In some stems only maxi-mum vessel lengths were measured, which is much faster th an deter-mining frequency distributions. Details of the paint and air meth-ods, which produce similar results, are given in Ewers and Fisher(1989a).

For each species the longest available unbranched stem seg-ments were selected for study. In most but not all of these segmentsthe leaves had abscised. In some cases, such as Bauhin ia vahl i iwhich has regularly spaced short shoots along its main axis, smalllatera l branches could no t be avoided. However, i n every case wemeasured vessel length only along the main axis. For maximumvessel length determinations it was necessary to obtain stem seg-ments longer tha n the longest vessel, but, as.we determined a p o s t -eriori this was rarely a problem since vessel lengths were not asgreat as we had anticipated.

Stem xylem diameter and vessel diameters were measured inthe stem segment at one half the length of the longest vessel. Thissegment was fixed in FAA, transversely sectioned with a slidingmicrotome at 30 gm, and stained with safranin or safranin andfast green. A Nik on photostereomicroscope with transmi tted lightcapabilities was used to prepare Kodachrome slides (diapositives)which were projected onto large sheets of white paper. Each vesselwas marked on the paper as its inn er diameter was measured witha ruler so that n one were measured more than once. The projectionresulted in spherical aberra tion errors of less tha n 1 . When avessel was no t ci rcular in transverse view, the m inim um and maxi-mum diameters were averaged. For narrow stems, the diamete rof every vessel in the stem was measured. However, wider stemsoften had well over a thousand vessels in cross sectional view.Rather than measure every vessel, we measured all the vessels inone or more sectors, with each sector having vascular rays formarginal boundaries and the pith and the vascular cambium asits inner and outer boundary, respectively. This avoided unduebias towards inne r or outer vesse ls. When possible we sampledat l east 100 vessels per stem. The above sampling procedure differsfrom that used in a previous study (1989b), where the diametersof only latex paint -fill ed vessels were measured.

Since normal distribu tion of the variables was highly question-able, correlati ons were determined using Spearman's nonpar amet-

ric coefficient of rank (Steel and Torrie 1980).

e s u l t s

A sum mar y of resul ts for a l l the species examine d ispresented in Table 1. The c omm on stat ist ics of mea nand median are given so that our resul ts can be moreeasi ly compared to previously publ ished surveys of xy-lem ana tomy, a l though such values fo r non -nor mal d is -t r ibu t ions shou ld be used wi th cau t ion . Mi n im um vesse ll eng ths cou ld no t be de te rmined by our me thods .

Most vessel length and vessel diameter dis t r ibut ions

were posi t ively skewed, with man y short a nd ma ny nar-row vessels and few long and few wide ones (Fig. 1).This is ref lected by the fact that mean vessel length wasgrea ter than the median l eng th in 96 o f the s t emsexami ned in Table 1 , and the m eans were always lessthan 50 o f the maxi mum. S imi la r ly, the mea n d iamete rwas g rea te r than the media n d iamete r in 99 o f thestems examined, and the mean was closer to the mini-mu m than to the ma xi mum in 100 of the cases .

For l iana species the overal l mean of the mea n vessellengths was 0.38 m (SE=0.05) , with an average medianof 0.26 m (SE=0 .04) and an average maxi mum of 1 .45m (SE = 0.13). For all l iana species the mean of the mean

vessel diam eter s was 41 ~tm (SE = 3.9), wit h an averag e

median o f 26 gm (SE=3 .1 ) and an average max imu mof 200 gm (SE = 13.2).

The mea n_ SE stem xylem diameters of the sampledstems were as follows: all l iana species, 8.1_+0.6 ram;tendri l c l imbers , 8 .2+1.2 ram; twiners , 7 .1_+0.6 mm;scramblers ( includi ng scramblers with occasional branchtendrils), 10.0_+ 1.0 mm. Wi th in the genus B a u h i n i a the

mea n s tem xylem di ameters were: shrubs 7.4_+ 1.6 ram;trees, 11.2 _+ 1.1 mm ; ten dri l cl imbe rs, 5.2 -t- 1.9 ram.

Table 2. Spea rman's coefficient of ran k (rs) for various combi na-tions of parameters. For ALL SPECIES, r~ is based upon the aver-age value for each species in Table 1. For ALL LIANA STEMSand ALL TR EE + SHRUB STEMS, each stem was individuallyincorporated into the calculations. The differences in n were dueto incomplete data sets for m any stems. NS =n ot significant at0.05 level of probability

Parameters rs n Proba-bility

All speciesmean vessel length x mean vessel diam 0.17median vessel length x median vessel diam -0 .0 6

25 NS25 NS38

8/11/2019 Ewers Et Al-1990

6/9

2 5 0E

[UI-LU

1 5 0