CHI%OMOSOME NUMBEgS IN THE MALVACEAE. I.
BY A. SKOVSTED. (E,mpi~:e Cotton G~'owi,ng Corporation, Cotton Research Station, T~'inidad, B. W.I.)
(With i[25 Figures in the Text.)
CONTENTS. I'A (4 I'] I. Imbroducfion 2(]3 II. History 263 III. Technique a,nd ma,LeriM 264 IV. CybologicM observations 264 V. Disctission and generM summary 289 VI. Summary 292 I%eferences . 293
I. INTRODUCTION. THE present studies were undertaken as part of a programme for eluci- dating the cytology of the genus Gossypium. It was anticipated tha~ chromosome nmnbers and morphology might be useful in distinguishing the genus from closely related genera. Furthermore, it was thought that a cytological study of the entire family Malvaceae might contribute to a bettcr understanding of the evolution of this family and consequently to the origin of the genus Gossypium. The family Malvaceae contains at least 800 species. In the present investigation approximately 120 of these have been examined. As this represents a small percentage of the total number, and as further investi- g'ations are in progress, the present work is factual in nature, and the discussions and conclusions of a preliminary character.
II. HIsTouY. Most of the relevant cytological work deals with the genus Gossypium only, the literature of which has recently been reviewed (Longley0a), Skovsted (19, 20)). A few species from ott~er genera have also been studied (Svensson-Stenar (23), Tischler (sh, 2a)). Only three comprehensive studies dealing with larger numbers of species have been published: two of these refer in particular to the flibiscus gro~ctp (Longley(*% Youngman(an); in the third, tile chromosome numbers of fourteen new species repre- 264 Chromosome Numbers in the Malvaceae. I. senting eight genera are recorded by Davie(a). These chromosome numbers are discussed in detail lager.
III. TECHNIQUE AND ~ATEr~IAL. Both roo~4ips and pollen mother ceils were exami~led in the deter- minatiou of chromosome numbers. The majority of the root-tips were fixed in Navashin's solution, and the buds in @arnoy-Navashin. In the improved technique developed during the invesCigaCion later fixations of root-tips were made in LewiCsky's fixative (2J), and buds were treated according to the technique developed for cotton09). All slides were stained in Gentian violet. The taxonomic arrangement~ of genera is that of Engler and Prantl; nomenclature follows closely Index Kewe'nsis. Most of the species examined were obtained from seeds supplied through the Botanical Garden of the University of Copenhagen, or from seeds bought from Haage and Schmidt, Erfurt. Some wild species from different parts of the world eolleeted by Dr S. C. I-Iarland and by Mr J. B. Hutchinson in India were kindly placed at the writer's disposal. To Dr O. Hagerup the writer is indebted for fixed material of species grown a~ Timbuktu in the Sahara. Species native to Trinidad were collected from nature by the writer.
IV. @YTOLOGICAL OBSEiZVATIONS. t YV~e tribe Malopeae. (1) The genus Malope. 2n Aut~hor M. trifida Car. (Fig. 1) ,t4 Davie (6), S. M. trifida (Fig. 2) 50 S. 2[. hispida Boiss. (Fig. 3) 44 S. In the present study the chromosome nmnber 2'n = 4,J: in M. t,r.ifida was confu'med from material obtained from Haage and Schmidt; another type of tile species obtained from Copenhagen had 2n = 50; morphologically the two types were very similar; chromosomes of sizes similar to those of M. tr'ifida were found in M. hislJida Boiss. (2) ~'he genus Kitaibelia. n 2n Aughor If. Li~dcmuthi Hort. (Fig. 4) -- 44 S. K. vitiJblia -- 42 D~vie (6) K. vitifolia WiHd, (2 types) (Figs. 5-6) 22 44 S. Numbm's de~ermined by the writer are m~rked wi~h "S". A. SKOVS~I'EO 265 In both K. Lindemuthi Herr. and K. vitifolia Willd. the chromosome number is here found to be 2n= 44, the chromosomes being of similar sizes; another type of K. vitiJblia showed n=22 in the first meiotic division.
The t~'ibe Malveae. (1) The genus Abutilon. 'a 2n, Author A. striatum Thompso~d 8 -- Kuhn (26) A. striatum T/~om,pson.i 8 16 J)~vie (6) A. striatum :Dicks (Figs. 7-8) 8 16 S. A. 'wmbellatum Sweet (Figs. 9-10) -- 16 S. A. crispum Sweet (Figs. 1 [-12) 7 14 S. A. gla,ttcnm G, ~on (Fig. 13) 14 -- S. A. Avicennae -- 42 :Bresl,~vetz (3) A. Avicennae Gaertn. (2 types) (Figs. 1,1-] 5) 21 42 S. A. giganteum ]?resl (Fig. 16) -- 42 S. A. indicu,n+ Sweet (Figs. 17-18) 2i 42 S. A. molle Sweet (2 types) (Pigs. 19-20) 2I 4:2 S. A..Regncllii Niq. (3 types) (Figs. 21-22) 21 42 S. Abutilon sp. (Fig. 23) -- 42 S. A burliest, sp. (fl'om Sudan) (Fig. 24) -- 42 S. Following the cytological observations reported here the genus ha, s been divided into two groups, one with 8 and the other with 7 as the basic chromosome number. 1 The first group contains: A. st,riatum with n=8 and 2n=16 and A. umbel,k~,tum Sweet. The latter species pos,~essed %=16 (Fig. 9) in five of the six roots examined, while one root was tetraploid with 2n = 32 (Fig. 10). The second group (basic number 7) comprises nine species, only one of which has been studied by previous workers : cytologically, A. crisl)um Sweet is the more primitive type with n = 7 and 2n = 14, while A. glaucum G. Don has n -- 1~; the remaining seven species all have ~ = 21 or 2n = ~2. Chromosome sizes differ somewhat from one species to another, but, since considerable variation in size is also found among the chromosomes in a single cell, no particular inference can be drawn. Most species possess one or two pairs of chromosomes which are easily distinguishable by their satellites. Only in A. crisl)Um was it possible to distinguish the wl{ole set of chromosomes on minute morphological differences.
1 It is interesting to note that the cytological division appears to be associated with morphological characters : the species witch n = 8 having five-lobed capsules and the species of the seven series poly-lobed capsules. I-[erbarium studies indicate that this morphological division is m~tural throughout the genus. Most species from all parts of the world have poly-lobed e~psules, while only a few--all confined to the New World--have five-lobed capsules. 266 Chromosome Numbers in the Malvaceae. I. (2) The genus Wissadula. 2~ Author W. contracta ]%. E. Fries (Fig, 25) 14 S.
The t4: somatic chromosomes k~re smMler than those of Abutilon crispum Sweet (Fig. 11).
(3) The genus Sphaeralcea. n 2)~ Author S. miniata Spaeh. (Figs. 26-27) 5 10 S. S, ,u~nbellata G. Don (Fig. 28) -- 34 S.
The chromosomes are much larger than those of the above-mentioned genera.
(~t) The genus )JIodiola. 2n Author M. "m'ullli[ida Moeneh (2 ~ypes) (Fig. 29) 18 S. The 18 somatic chromosomes are similar iu size to those of S'phae,ralcea.
(5) The genus Lavatera. n 2v, Author L. trimestris 7 14 Davie (6) L. lrimesO'is L. (3 types) -- 14 S. L. arborca L. -- 36 D~vie (6) L. arborea (2 gypes) (Fig. 30) -- 42 S. L. cclche,m,iria~a 22 -- Davie (6) L. cachemiriana Cambess (Figs. 31-32) -- ,12 S. L. ,mauritanica Dueh. (Fig. 33) -- c, 84 S. L. cretica L. (Fig. 34) -- c, 112 S. L. Olbia L. 20 40 D~vie (6) L. th,u,ri'~lgiuca 20 -- Svensson-Sten~r (23) L. thuringiaca (2 types) (Fig. 35) 22 4~ S. L. ~)lcbcia Sims (Fig. 36) -- 43 S. The chromosome numbers of five species have already been recorded. Four of these were examined dnrhlg the presegt investigations, but only the chromosome number of L. t~'i,mest~'is was confirmed. Two types of L. a,rborea L. and L. eachem@iana Cambess had 2n=~2; in the latter species, tetraploid tissue with 2n=8L1 was observed. L. mauritanica Duch. had % = e. 84 and L. eretica L. approximately 112 somatic chromo- somes. These species are apparently poiyploids of seven compared with L. thuringiaee L. which has n=22 and 2n=44; L. plebeia Sims affords an intermediate number with 2n = 43; the meiotic divisions of this species have not yet been studied. It may be anticipated that cytological studies of other species in this genus will provide useful results as different chromosome numbers are apparently represented. n. ~KOVSTE]) 267 (6) l'he genus Althaea. n 2~ Author A. can~;mbina L. (Fig. 37) -- 28 S. A, a,ptcrocarl)r,~ Fcnzt (Fig. 38) -- 42 S, A . .fic~blia -- 44 Davie (6) A. fieifolia (Jay. (Fig. 39) -- '.42 S, A. Heldreichii Boiss. (Fig. 40) -- 42 S, qOicinalis -- c. 40~t4 D,~vie (6) q[#ci*~ali,s L. (2 typos) (Fig. 41) -- 42 S, pcdlida W~dcl. et [{it. (Fig. 42) -- 42 S. TOSEC(, 21 -- Kcssetcr (12) ~'08~Cb ] 3 -- Burkcbt (4) rosen C~v. (4 types) (Fig. 43) -- 42 S, h ybrida Heft. (Fig, 44.) -- 42 S. ,si'nc~sis C~v, (]fig. 45) -- 70 S, ar,meniaca Tcnoro -- c. 84 S, Hoke;~ackcri ]3oiss. ot }Iuot. -- c. 84 S. ]e,;'agujevace~mis :P~ncic (Fig. 46) -- c. 84 S.
In the presen~ study twelve species proved to be simple polyploids Of seven. Slight variations were observed in the chromosome sizes of the different species. 0nty A. eannabina has chromosomes significantly larger than the other species.
(7) The genus Malva. n 2n Author M. oxyloba ]3oiss. -- 42 Davie (6), S. M. sylvestri.s 20 -- Latter (13) M, sylvestris L. 21 42 D~%vie (6), S. M. rot~*ndijbliu L. -- 42 Davie (6), S. M. moschata 20 -- Svensson-Stenar (23) M. moschata L. (Fig. 47) -- 4-2 S. M. nicaeg,~tsis -- c. 64 Da, vie (6) M. nicaegnsis All, (2 types) (]rig. 48) -- 42 S. 3[. Alcea L. (Fig. 49) 42 -- S. M. verticillctta ]3. c. 42 -- S. M. brasiliensis Desr. (Fig. 50) -- c. 112 S. ~li. crispa L. (Fig. 51) -- c. 112 S. 3[, borealis (=pvsilla Sm.) 20-30 -- Svensson-Stenar (23) M. borealis Walhn. (Fig. 52) -- 76 S. M. 2)al'mala c. 20 -- Svensson-Stenar (23) M. l)ctrviflora L. 21 42 Lilienfeld (15)
In the present study the ehromesome numbers n = 21 or 2n = 42 from M. oxyloba, M. sylvestris and ill. ,rotu,ndifolia have been confirmed and they fall into tine with n=21 and 2,n=42 found in M. parviflora. In contrast to these, the numbers reported from 3I. borecdis, l]/_[, moschatc~, M. pabnata, and M. nicae~nsis do not agree with the present observations. The majority of the species belong to a seven series, except M. borealis Walhn. which has 2,~=76, though i~s chromosomes are of similar sizes to those of tile o~her species. 268 Chromosome Numbe*s in the Malvaceae. i. (8) The genus Sidalcea. n 2n Author S. ca~dida A. Gr~y (Figs. 53-56) -- 20 (21) S. £'. malvaeflora A. Gr~y -- c. 56-62 S.
S. neo-mexicana A. Gr~y 13 -- Tjebbes (27)
Only ~h, bwo species S. candida, A. Gray and S. malvaeflora A. Gray were available during the present study: of these S. ccbndi&~ has 2~= 20 and 2n = 21 in different cells of the same root; since one of the 21 chromo- seines is distinctly smaller than the others, the variation in number is probably due to an uneven fragmentation of one of the larger chromo- somes; S. malvaeflora has about 60 somatic chromosomes similar in size to those of S. candida.
(9) The genus Callirhog. n 2n Aul~hor 6'. involucrala A. Gr~y 12 -- Kesseler (12)
C. linearilobct A. Gr~y (Fig. 55) -- 42 S.
(10) The genus Napaea. 2n Author N. dioica L. (Figs. 56-57) 28 (29) S.
Similar variations to those of Si&dcea candida were observed in the chromosomes of N. dioica L., the only species in the genus. Some cells had 2n=28 (Fig. 56) and others 2n=29 (Fig. 57). One pail" of chromo- seines is eharacterised by a strong median constriction, though this pair does not cause bhe fragmentation.
(11) The genus Malvastrum. n 2~ Author
M. cct;pcnse 21 -- Svensson-S~en~r (23) M. capcnse Garcke (Fig. 58) -- 44 S, M. scol)a,~'ium, A. Gray (Figs. 59-60) 12 26 S. M. coromemdelianum ¢4arcke (Figs. 61-62) 12 24 S.
ll'[.. Sl)icatum A. Gray (Fig. 63) -- 24 S. 1ll. greenmania,nwm, Prose (Figs. 64-65) 16 32 S.
M. grossulariaefolium Oareke (Fig. 66) -- 42 8. M, lime,use Ball (Figs. 67-68) ] 5 30 S.
M. peruvianum A. Gr~y 15 -- S.
M. cape'nse Garcke has been recorded with n: 21, but when material from the species was examined dm'ing the present study it was found to have 2n=44. Seven other Species were examined and showed fear different chromosome numbers: bhree species have n= 12 and 2~= 24, one n= 16 and 2n= 32, one 2'n= 62 and two 'n = 15 or 2'n = 30. Ao SKOVSTED 269
S
~%Qse~O o
~% I~ I
3 4
@
5 5 Figs. 1-6. The tribe ~I~lopeae. ( x 3100.)
Journ. of Genebics xxxI 18 270 Ch~'omosome Nzvmbe~'s in the Malvaceae. I. ¢
5
12 10 I1
0 2" ~'<.¢~. @ k:4J - @ @$$ 13 14 15
16 Figs. 7-18, The grams Abulilo~, ( x 3100.) A. ~KOVST]~D 271
~,O00 20 21
@ @
ee o 0 % • # ¢,, e #"~ 8~ 22 23 24
J')1 0 @ 25 26
~27
28 Figs. [9-29. The gcne,rt~ A b~tt.iloT~, p.p., Wissad'*da,, ,gp]taeralcect e~nd l~fodioht. ( x g 100,)
18-2 272 Ch~'omosomeN~embe~'~ in the Malvaceae. I.
%.9~,~ ~~, _
33
® ° O e @
~ 35
$ # d 34 " 36 Figs. 30-36. The genus Lavafera. ( × 3100.) n. ~KOVSTED 273
@~ q 38
37
('4
d~ 43 44 42
45 :Figs. 37~J:6. The genus Althaea. ( × 3100.) 274 Ch~'omosomeNumber's in the Malvaceae. I.
r
47 48
%* @O @ ~
0~" 0 ~ ® °e %
49 50
91 52
]?igs. ,]7-52. The geaus M~dva. ( × 3100.) A. ~KOVSTED 275
d~¢]i 4;
54
,% 57 Figs. 53-57. The gener~ Sidalcca, Callirho~ ~,nd Napaea. ( × 3100.) 276 Ch,romosome Number's in the Malvaceae. I.
#a;r 59 W" 5~
% b e~
63 @
~O' f 64
55
65
6 ~fT~ 57 68 Figs. 58-68. The genus Malwt6'trwm. ( x 3100.) A. SKOVSTED 277
~~~ t~ ~ ~ 70 69
o e Q~O o @ ee e 73
~ 72 74
oQQ ~ee~eQe ~ ~O ~ • @ O G ~f Oee ~ coo ¢-~e 75 ¢~ ~ 76 r 77 Figs. 69-77. Tho gener~ ~'ida z~nd Anoda. ( × 3100.) 278 Chromosome Numbers'in the Malvaceae. I.
~ ~ ~J
78 ~ 79 81
. ¢~ do"-~ ¢,~'d¢ 82 8O
83
85 :Figs. 78-86. The gener~ ~llalachra, Urena a~nd Pavonia. ( x 3100.) A. ~DI~U V~] I 279
~ig. 87. llfaf,vavlsc'tt.~' sp. 2n=c. 8~t. (×3100.) 280 Ch~'omosome Number's in the Malvaceae. I.
@
@ % @ @ @ @ @
O 88 @ 90
94 9~ 92
• Q @ @ @ @ e o @ @ @ e v
@ e @@ @ @ @ @ @ o @ e 95
96 98 I~igs. 88-99. The genus Hibiscus. ( x 3100.) A. ~KOVSTED 281
101 100 102
° oo.v: 103
AJ~ 106
P %
@
105 107
103
@ a o o O ~ ,~ l~ ¢ % a¢$ ~ O
o @
o I09 I08 110 Figs. 100-110. The genus Hibiscus p.p. ( × 3100.) 282 Ch~'omosome Number's in the Malvaceae. I.
@
112
o~ °
a o @~ Q Q @ o 114 115
¢ ~g~ fg g~
J ~ 113
fI6 Figs. 111-116. The gener~ HibiscT~s p.p,, Cie;t¢ttgosla ~nd Go,~sypioides. ( x 3100.) A. ~I[OVSTED 283
m C$ J~
117 119
,e~¢ 120 121 122
123 124 :Figs. ll7-125. The genus Goss/]'piu~ ( × 3500.) 28¢ Ch~'omosome Numbers in the Malvaceae. I. (12) The genus Sida. n 27~ Author £% urens L. (Fig. 69) -- 32 S. N. spinosa L. (Fig. 70) 7 -- S. ~'. rhomb*ifolia L. (Figs. 71-72) -- 1,t S. ;S'. acuta ~m'm. (Fig. 73) 14 -- S. S. triloba Car. (Fig. 74) -- 28 S. S. grewioidcs Guill. e~ Pert. -- c. 28 S, S. veronicaejblia Lain. (Fig. 75) 28 -- S. The eigh~ species examined cytologically may be arranged in two different groups: (a) S. ~o'ens L. with 2n=32, and (b) a group of six species with seven as the basic chromosome number. S. rhombifolia L. showed 2n = 1~ and 2n = 28 in tetraploid tissue and S. grewioides Guill. et Perr. shows about 28 chromosomes in somatic mitosis of the flower buds. (13) The genus Anoda. n 2.n, Author A. hclslata Car. (Figs. 76-77) 15 30 S. A. IVriffhtii A. Gray c. 30 -- S. The chromosomes of A. hastata are large and are similar in size to those of Sphaeralcea ,miniata (n = 5, Fig. 27). A. W~'ightii showed about 30 chromosomes in the first meiotic division. The t~'ibe Uq'eneae. (1) The genus Malaehra. n 2n Author M. alceiJblia Jacq. (Fig. 78) -- 56 S. M. capitata L. (Fig. 79) (~. 28 56 S. M. fasciala J,~cq. (Fig. 80) -- c. I12 ,S. All three species studied appear to be polyploids of a seven series. (2) Thegenus Urena. 2n Anbhor U. lobata L. (:Fig. 81) 28 S. U. sinuata L. (:Fig. 82) 28 S. The two closely related species U. lobata L. and U. sinuata L. h~ve both 2n = 28, their chromosomes being of similar sizes. (3) The genus Pavonia. 2n Author P. pracmorsa Car. (3 types) (Fig. 83) 28 S. P. Schi,m,periana Hochst. (Fig. 84) 28 S. P. Kolschyi Hochst. c. 28 S. P. hastala Car. (Fig. 85) 56 S. P. spinifex 42 D~vie (6) P. spinifex C~v. (2 types) (Fig. 86) 112 S. One species, P. spi,;'dJ'ex, is recorded with 2n = 42, but this number differs from that observed in the presenb study. The five species examined A. SI;OVSTED 285 appear to be nlembers of a series with seven as the basic chromosome nnnlber. (4) The genus Matvaviseus. 2n Author Malvaviscus sp. (Fig. 87) c. 84 S. The species studied is a hort,icultural type usually called M. arboreus Cav. ~ It has approximately 84 somatic cln'omosomes. The meiotic divi- sion is, however, irregular, a.t least I0 univalents being generally seen in the metaphase of the first division. The t~'ibe Hibisceae. (1) The genus Hibiscus. ~ 2n Author H. phoenice,us L. (Fig. 38) 11 -- S. Hibiscus sp. (.Fig. 89) -- 24 S. 1t. cannabinus L. -- 36 ]3resl~vetz (3) H. cannabinus (Figs. 90-91) 18 36 S. 1I. Sabdariffa L. (Fig. 92) 36 72 S. Hibisc,us sp. (Fig. 93) 36 72 S. 2t. su.rattc~sis ( ? =sura.ns~sis L.) 36 (39 ?) -- Nargadant (25) H. gossypinus Thunb. (Fig. 94) 14 -- S. H. Trion,u,m (=africanus) -- 56 Davis (6) H, Trion'um L. (Fig. 95) 28 56 S, H, Parl;eri Baker (Fig. 96) -- 34 S. H. ~b'olandra L'I-[erit. (2 types) (Figs. 97-99) 17 34: S. H. vitt~foli~ls (Fig. 100) -- 34 S. H. cocci neus Walt. -- 37-50 iKesseler (12) H. coccineus (Fig. 101) -- 38 S. H. ross'us There (Fig. 102) -- 38 S. H. militaris Cav. 19 (20) -- Longley (16) H. Moscheutos L, (=H. l)ahtstris L.) 19 (20) -- Longley (16) H. t.rieusl)is [Banks c. 40 -- ¥oungman (31) It, lVaimeae A. A. ]~eller (Fig. 103) 42 -- S. I-l. tiliaccus L. c. 48 -- Youngman (31) H. tilioccus (Fig. 10'4-) -- c. 92 S. H. collinus tZoxb. (Fig. 105) -- c. 92 S. H. ~osa-sinensis L. c, 72 -- Youngman (31) H..Rosa.sinensis (]Pig. 106) -- 92 S. H. mutabilis L. -- c. 92 S. H. Manihot 30 -- Teshima (24) H. Manihot L. (3 types) (Figs. 107-108) 33 66 S. H, Abelmoschus L. (Figs. 109-110) 36 72 S. H. ficulneus L. (Fig. 111) -- 78 S. H. essulsntus L. 59-60-61 -- ](renke (26) H. esculentus L. -- c, 132 Breslavetz (3) H. esculcntus L. 36 -- Teshima (2,t) H. esculct~tus L. (3 types) (Figs. 112-113) 65 130 S. This genus includes at least 200 species. These have been [axonomi- sally grouped together in several different ways. Cytological determina- 1 Morphologically, bhe [ype under observagion is disginetiy different from the wild growing 11I. arborcus Car. Its cytological behaviour indicates that it is probably a hybrid although its origin appears unknown. It is cmmnonly cultivated in Trinidad where it is vegetatively reprodneed as it is apparently completely sterile. In Kew J[-Ierb-~rium the l~ype is represented from gardens on the Gold Coast. Journ. of Genetics xxxr 19 286 Chromoso~e Numbers in the Mcdvaceae. I. tions are in agreement with several of Hochreutiner's subdivisions(n). Sufficient data are not yet available to test all these groups. The species have therefore been arranged in seven groups which up to the present appear coherent on a chromosome basis. (a) H. 2)hoeniceus L. is morphologically isolated from other species s~,udied in the genus. Its chromosome number n= tl is so far the lowest in the genus. (b) Species which are members of a series with 6 as the basic chromo- some number: Hibiscus sp. (from India) 2,,~= 24; H. ca,,~abinus L. q~ = 18 and 2%=36; H. Sabda, riJfa L. and Hibiscus sp. ~ both with n=36 and 2~z=72; H. sura aensis (?=H. surane',~sis L.) which is recorded with qa=c. 36 (25) is probably also a member of this series. (c) Species representing polyploids of seven are: H. gossypinus Thunb. with n= 14, and H. 51'rioq~um with n = 28 and 2n= 56. (d) The chromosome numbers n = 17 and 2~ = 34- were found in three species: H. Parlce,ri Baker, H. Sola,,~dra L'Herit. and H. vitifolius L. (e) Two species H. eoccineus Walt. and H. roseus There have both 2q~ = 38. Apparently H. ,militaris Car. and H. Moseheul.os L. ( = H. pains- iris L.) which have been recorded with n = 19 (or 20) also belong to this group. (f) This group contains a number of species which are high poly- ploids. The following three species have been recorded: H. t rieus2)is Banks, n=e. 40, H. tiZiaceus L., ~=e. 48, and H. Rosa-siq~e,~zsis, ~=c. 72. In the present study H. Wai'meae A. A. tteller was found to have n = 42, and H. tiliaceus L., H. collinus text., H. gosc~-si~'~ensis L. and H. ~n,~l.cb- bills g. all showed 92 or about 92 somatic chromosomes. The meiosis of a type of H. Rosa-siq~ensis was examined, but this proved to be very irregular with a large number of univalmxt chromosomes. The type is almost completely sterile. (g) The Abelmoschus group. ~oo.r species studied were all found to have small chromosomes: H. Man.ihot L. with ~=33 and 2,z=66, H. Abdmoschus L. with q, = 36 and 2~a = 72, .H. ficulneus L. with 2n = 78, and H. ese~l.Ze~~t~tsL. with q? = 65 and 2n = 130.
(2) The genus Thespesia. 2'~a Aul) hor T. macroph!/lla l~lumc 26 Youngman (33) T. 2)el)sines Soland: 26 Youngman (33), S.
In K.ew lferbarium this species is represent~e4 by ~bypes ti'om l{eny~ (Garchmr 138'4) and Ogan&~ (Naitland 59 and Liebenberg 838). il) appears +so be an undeseribed species closely alHcd to H. Sabdarij'fi~. A. SKOVSTED 287 In the present study the chromosome number of T. populnea was confirmed. (3) 2~hegenus Cienfugosia. ~ 2~ Author C. helerophylh~ Spach 10 -- Longley (1.6) C. Hildebrandkii Garckc -- 26 Ymmgman (33) 6'. Hildebrandtii (Fig. 114) -- 22 S. The chromosome nmnber 2n=26 has been recorded for C. Hilde- brandtii Gareke. In the present study a type of this species was examined and found to have 2n = 22. (4-) The genus Shantzia. n Author S. Garcl~:cancc Lewton 13 Longley (16) (5) 2~hegenus Gossypioides gen.nov. n 2n Author a. Kirldi (Mast.) comb.nov. (Figs. 115-116) 12 24 S. (19) Exclusion of the species (~ossyl)ium Ki'dcii Mas~. from the genus Gossy/pium has been proposed by Harland(10) for the following reasons: (1) it would neither graft nor hybridise with other species of the genus, and (2) certain of its morphological characters, i.e. a square stem, are not found in the genus Gossypium. This view has been strengthened by a determination of its chromosome number to be n = 12 and 2n = 24. It may further be mentioned that the main morphological characters used in the separation of the sub-tribe Hibiscus from the sub-tribe Gossyl)ium are: (1) the presence of joined stigma-lobes in gossypium and separate stigma-lobes in Hibiscus, and (2) ~he shape of the seeds. From its stigma- lobes, Gossypium Kirfcii belongs to the sub-tribe Hibiscus, but, from the shape of its seeds, it belongs to the sub-tribe Gossypium. It will not graft with any species of Gossypium(9), nor with any other species of the tribe, though it grafts easily within its own species. As it probably occupies an isolated position, it is proposed to place it in a separate genus under ~he name Gossypioides. (6) The genus Gossypium. n 2n Author O. arid'~t (P~oso and Standley) 13 26 8.(19) comb.nov. (Fig. 117) O. Harlcnessii T. S. Brandeg. 13 -- Webber (28) G. m'mm(xia.n~m. Kearney (Fig. 118) -- 26 Longley (16), S. (19) G. armouriaw~tm Kcarnoy 13 -- Wobber (2S) G. Davidsonii Kellogg 1.3 26 Lans and Longley(9), Longloy (i0), S. (19), (21), Webbcr (28) G. Klotzschia~um Anderss. -- 26 S. (19) (Fig. 119) G. Klotzschianum Anderss. 13 -- Webbcr (28) 19-2 288 Chromosome Nv, mber8 in the Malvaceae. I. g. trilobum (~ioq. e{; Sess. ex DC.) 13 26 Longley (10, 16), S. (19) comb.nov. (Fig. 120) G. arboreum L. ([Fig. 121) 13 26 Nikolgjeva (35), Denham (8), ]3,%nerji(1), Longley (16), S. (19), ~'Vebber (28) G. herbaceum L. 13 26 Nikoh~jeva (35), Denham (8), B~nerji(1), Youngman (32), Naka~omi(18), Long- ley (l 6), S. (19), D~vie (6), Webber (28) ~'. ,bTocksii MasC. (Fig. 122) 13 26 Youngman and Pande(34), ~Banerji(1), S. (19), Davis (6) (4. anomalum Wawra alld I)eyr -- 26 S. (20) (Fig. 123) G. Sturtii [F. Nuell. 26 -- Lgns (9) G. Sturtii 13 26 S. (10, 19, 21), Longley (16), \Yebber (28) G. barbadcnsc L. (Fig. 124) 26 52 Nikol~jeva(35), Denham(7), 13eM(2), Nt~kal~omi(18), Longley(16), S.(19). Webber (28) G. hirsutum L. 26 52 Nikolajeva(35), ])enham(8), Beal(2), ~B~nerji (1), Nakat, omi (18), Longley (16), S. (19), Davis (6), ~¥ebber (28) G. lm,rl~urascens Poir. 26 52 Nikotajeva (35), S. (19) G. taitense Purl. 26 -- S. G. Darwinii Wag~. 26 -- Webber (28), S. CA Iome~dosam Nugt. ex ~eem. 26 52 Lans (9), Webber (28), ~S. (Fig. 125) Cytologically this genus has been divided into three main groups (20). The chromosome numbers of mosg species have been recorded, but only a, few have been illustrated cytologically. (a) Species with 26 small somatic chromosomes, ft. ari~h~m (I~ose and Standley) comb.nov. (=E~'ioxylum a.); G. armourianu~ Kearney (= G. Har/cnessii(19, 2o)); G. Davidsonii Kellogg; G. Koltzsehiaqzum Anderss. ; and[ G. t~'ilobum (Mo 9. et Sess. ex DC.) comb.nov. (=I~Nenhouzia t. = G. TN~rberi Tod.=Thu,rberia thes2ssioides A. Gray=G. lanceaq/brme Mists ex Britten (19, 2o)). (b) Species with 26 larger somatic chromosomes. No difference ham so far been observed between G. arboreum L. and G. herbaceum L. Both species have chromosomes of the same size as G. Stoe/csii Mast. The chromosomes of G. anomalum 1 Wawra and PeyT (= G. @'icanu,m,(2o)) are somewhat smaller. In each of the species, two pairs of chromosomes carry satellites; in G. anomcdu,,t ~hese two pairs are easily distinguishable by the strong median constriction in one' of the pMrs. This group also includes 6'. St~o'tii F. Muell. (20). (c) S2)ecies 'with 52 somatic eb'omosomes. So far no difference has been observed in the cln'omosomes of G. barbadense L., G. hirsutum L., G. pu~Nurascens Poir., G. ta;itense Purl., G. Da,rwinii Watt. and G. tome,n- tosum Nutt. ex Seem. They all have ~ = 26 or 2n = 52. 1 Tlfis species is of ben assigned ~oghe genus Cie~fzff/osia. on the character 'hla.rrow brae~s". In ~hc genus Goss//pium, however, this ehargcger appears to be of inferior taxo- nomic value: ef. (7. armourictn'um and G. arid~tm. On all obher morphologieM characters, and on eyt~ologieM and geneCieM grounds (22) l~his si)eeies is a aossy/,,,~,,. A. SKOVSTED 289
V. DISCUSSION AND GENERAL SU~[I~IA.I~Y.
All known chronlosome numbers in the Malvaceae are entered in lists at the head of their respective genera. Since Winge(20) first drew atten- tion to clhromosome series in plants, most cytologisbs have tried to arrange their results in one or more chromosome series. Since the present investi- gation is of a preliminary nature, it is enough to state provisionMly that evidence is forthcoming which indicates tlle presence of the following series : (1) a seven series represented by the numbers 7, 14, 21, 28, 35, ~12 and 56 ; (2) a five series represented by the numbers 5, 10, 15 and 25; (3) a six series represented by the numbers 12, 18 and 36; (4) an eleven series represented by the numbers 11, 22 and 33; and (5) a thirteen series represented by the numbers 13, 26, 39 and 65. Apart from these, several odd nmnbers are present. Much more information is necessary, however, before an adequate discussion of the relationship between chromosome-number and taxon- omy can be undertaken. Only a few points will therefore be mentioned here. Malopeae. Species of the tribe Malopeae, polyploids of II, all possess chromosomes which are similar in size. In Malope trifida two types were found, one with 2n = ~ and another with 2n = 50. ~]~alveae. Two different cytological groups are present in the genus slbutilon, and these two groups appear to be distinguishable a,lso on morphological characters: the first eharacterised by large chromosomes, the basic number eight and a five-lobed capsule; the second by much smaller chromosomes, numbers belonging to a seven series, and a poly- lobed capsule. The only species so far studied from the genus l¥issadula has 2n=l~. The genera Modiola and ~5'phaeralcea, stand out from the above-mentioned genera not only on account of their chromosome size, but also by reasou of their cl~romosome numbers (9, 5 and 17). The difference in the various species of the genus Lavatera is so marked that further studies are necessary. The genera Althaea and Malva, on the other hand, form homologous groups cytologicMty, M1 the species being members of a seven series. Further studies appear necessary in the genera Callirho~ and ~idaleea, and also in the genus Malvast~'um. In the latter genus a study of eight species supplied five different chromosome numbers, t2, 15, 16, 21 and 22. The species with_ 21 and 22 belong to one section of the genus, while the other species are grouped in another 290 Ulwomosome N%mber8 in t]~e 2]fcdvaceae. I. section. Of these, however, the three species with ,)z= 12 are morpho- logically more olose]y allied to each other than to any other species studied in this section. These numbers are interesting in that they suggest the need for further cytological and taxonomical consideration. The chromosome numbers in the genus A,~zoda, iv 15 and o. 30. The numbers 7 and 16 are found in the genus Sida. U,reneae. All the species of this tribe are simple polyploids of seven. I-Iibiseeae. The H,ibiseux group. Species of the genus H'ibiseus are cytologically very heterogeneous. It is not improbable that these species will later be reclassified into a number of genera. Chromosome numbers alone, however, are no~ suffieien~ for the basis of a natt~ral elassifieatiou. The sub-genus _/lbelmoseh~s supplies an example of the diltieulties en- countered: although morphologically Abel,moselle,s is a very distinct sub- genus in Hibiscus, the chromosome numbers belong to three series, 11, 12 and 13. Successful hybridisation between three -/lbelvzosehus species ~ indicates that all are probably secondary polyploids, some of their chromosome complements being of common origin. Similarly, the groups with ~ = 17 and ~ = 19 are also probably secondary polyploids. The taxo- nomical sections are here associated with differences in chromosome numbers. The groups with polyploids of six (12, iL8 and 36) is particularly interesting because it includes the two economically important species H. ca,nnabin~s and H. Sabda~'iffc~ with n=18 and n=36 respectively. Hybridisation experiments between these two species merit further investigations. Hibiseeae. The Uossyfoi~m group. This grmlp is cytologically ehara, c- terised by the chromosome number 13: only Cie~i~9osia with 10 and 11 and Gossg2)ioides with 12 being exceptions. This latter genus has here been separated from ffossyTi~em on cytological and morphological char- aeters. Gossy~)ium is undoubtedly the best-known genus in the l)'~alvaceae. Cytological, morphological and hybridisation studies indicate that Gos- syT/zvm, is a well-founded geuus(-9~). On several occasions it ham been suggested that the chromosome mtmber is a secondary polyploid,
t:[ybrids bcLweetl H. escMc~tns and H. Ma:~dl*og tlave been reported by Teshima (2ol). The cross only succeeded when H. ese'*elet~t.,ls was used as female parent. Hybridisat.ion experiment, s between H. Abel.moselvus (n=36), H. Mcmil, ot (n=33) and H. csc.ulenl'us (n=65) were ab~eml)Led by the writer. No success at, tended the crossing of the first two species with each other: H. Ma~dho~ used as female produced only empl,y capsules, and H. A bel.mosclv~ts used as female produced capsules eongMning in all 600 empby seeds. They both crossed readily and produced viable hybrids with H. esc**le'~t'~l.s used as female, and in ghe present exl?eriments the reci/~roea.1 cresses were also suecessfifl with II. 2?ia:tdhol, while Llle cross H. Abelmosch~*s × H. e.s'cf~lenlus only produced empty seeds. A. SI
VI. Su~ra~Y. 1. In the presen~ study the chromosome numbers of abon~ 120 species representing 25 genera of the family Malvaceae have been described. The following cl~'omosome numbers were found: 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 25, 26, 28, 33, 35, 36, 38, 39, 42, ~16, 56 and 65. 2. Evidence has been presented in favour of the following chromo- some series: (a) a five series (5, 10, 15, 25); (b) a six series (12, 18, 36); (c) a seven series (7, 14-, 21, 28, 35, 42, 56); (d) an eleven series (11, 22, 33) ; and (e) a thirteen series (13, 26, 39, 65). 3. In most genera, all species examined are members of the same chromosome series (i.e. Althaea, Pavonia, Gossypium). Some genera, however, contain different chromosome series, i.e. Abutilon (8 and 7 series); Malvastrum (12 and 15 series, and a few numbers represented by a single specimen); and Hibiscus (ll, 12 (18, 36), 14: (28), 17, 19 and several others). The cytological groups in these genera appear to be associated with taxonomical groups or certain morphological characters (cf. Discussion and General Summary).
AC.t~NOWI~EDC~' ~r~NT. I wish to express my gratitude to Sir John Farmer, F.I{.S., who first drew my attention go the importance of ~his study, and[ to Dr S. C. Harland and Prof. E. E. Cheesman for reading through the manuscript and making critical suggestions. A. Si~.o VSTED 293
I~EFEI~ENCES.
(1) B,~RJI, J. (1929). "The chromosome nmnbers of India.n cot~,ons." Ann. Bet. 43, 604-7. (2) BE.~L, ,I. h~. (1928). "A study of ~he heterotypic prophases in the microsporo- genesis of cotton." Cellule, 38, 245-68. (3) BE~ESnAVm'Z,L., MEDWEDEWA,G. and l~'L~ai'r%IV[. (1934). "Zygologisehe Unter- suchungen der _Bastpflanzen." Z. Ziicht. i9, 229-34. (4) ]~UI~KETT, G. W. (1932). "Chromosome numbers in Althaea rosen." Scie.l~ce, 75, 488. (5) D:~I~e~'o~, C. D. and 15'[OFF~TT, A. A. (1930). "Primary and secondary chromosome balance in Pyrus." J. Gcnet. 22, 129-51. (6) DAvI~, J. I:l:. (1933). "Cytological studies iu the 15![alvaeeac and certMn related families." Ibid. 28, 33-67. (7) D~r~a~r, H. J. (1924). "The cytology of the cotton plant. I. Mierospore formation ill Se~ Island cotton." Ann. Bet. 38, 407-32. (8) -- (1924). "The cytology of the cotton plant. II. Chromosome numbers of Old and New World cottons." Ibid. 38, 433-8. (9) t-IaaLa~D, S. C. (1929). "Cotton notes." T~'op. Agriculture, Trin., 6, 351-2. (10) -- (1932). "The genetics of Gossy2)iu,m." Bibliogr. tenet. 9, 107-82. (11.) HOCm~UTI~R, ]3. P. @. (1900). Revisio~ du genre Hibiscus. 169 pp. Gengve. (12) K~SSEL~I~, E. yon (1932). "Obserwgions on chromosome number in Althaea rosen, Callirhog involucrata, and Hibiscus coccineus." Amer. J. Bet. t9,128-30. (13) L,~TT~, N:. J. (1932). "The meiotic divisions in the pollen mother cells of Malva sylvestris." Ann. Bet. 46, 1-I0. (1~) Lmw~Nc~, W. J. C. (1931). "The secondary association of cl~'omosomes." Cytologia, 2, 352-84. (15) LmIEN~5~, F. A. (1929). "Vererbungsversuehe mig sehlitzbl~tt~rigen Sippen yon Malva parviflora." Bibl. Genet., Lpz., 13, 1-214. (16) LONC'L~g, A. E. (1933). "Chromosomes in aossypium and related genera." J. agric. ~es. 46, 217-27. (17) MO~'~T, A. A. (1934). "Cytological studies in cultivated pears." Ge,netica, t5, 511-18. (18) N~K~To~, S. (1931). "Hybridisation between Old World and New Workl cotton species, and the chromosome behaviour of the pollen mother cells in the F~ hybrid." Ja~). J. Bol. 5, 371-84. (19) SKovsw~, A. (I933). "Cytological studies in cotton. I. The mitosis and meiosis in diploid and triplokl Asiatic cotton." Ann. Bet. 47, 227-57. (20) -- (1934). "Cytological studies in cotton. II. Two interspeeific hybrids between Asiatic and New World cottons." J. Goner. 28, 407-24. (2].) -- (1935). "Cytological studies in cotton. I]:I. A hybrkl between Gossyl)i~o~, Davidsonii Nell and G. Stu,rtii F. ]~'[uell." Ibid. (in press). (22) -- (1935). "Some new interspecific hybrids in the genus Gossypium L." Ibid. (in press). (23) Sv]~NssoN-S'rn~n, A. I:[. (1925). "Embryologische Studien. I. Zur Embryo- logic einigcr Columniferen." A kad. Afh,. Uppscda, pp. 1-75. 294 Chromosome Numberd in the Malvaceae. I.
(24) TeS~-H~'~% T. (1933). "@eaotieM and cytological studies on an intorspecific hybrid of Hibiscus esc'alentus L. and Hibiscus llIanihot L." J. Fac. Attic. Ito]dcaido Univ. 34, 155. (25) TmormEn, G. (1927). "Pflanzliche Chromosomon-Zahlcn." 2I'abul. biol., ]Bed., 4, 1-83. (26) -- (1931). "Pflanzlie}m Chromosomen-ZMllen." ]bid. 7, 109-226. (27) T.T~B~s, K. (1928). "The chromosome numbers of some flowering plants." Hereditas, iO, 328-32. (28) W~m3ER, J. hi. (1934). "Chromosome nmnber and meiotic behaviour in Gos- sypium." J. attic. Res. 49, 223-37. (29) t¥I~(~, O. (1917). "The clu'onlosomes. Their nmnhers and genorM importance." C.R. Lab. Caxlsberg, i3, 131-275. (30) -- (1927). "Zytologische Untersuchungen fiber die N~tul' mMigner Tu- moren. I. 'Crown gall' der ZuekerHibe." Z. Zellforsch. 6, 397--'t23. (3].) ¥ou~c~IA~, W. (1927). "Studies in the cytology of the Hibisceao. I." Ann. Bet. 41,755-78. (32) -- (1931), "Studies in the cytology of the }Iibiseeae. II. The behaviour of the nucleus during ceil division in the roo~ tips of Thesl]esia l)op~dnea and comparative observations of the phenonlena in some related plants." [bid. 45, 49-72. (33) -- (1931). "Studies in the cytology of the }Iibiseeae. III. A study of the prophase of the nucleus of the pollen mother cell el ~Phesl)esir~ l)olJuhtea." Ibid. 45, 211-27. (34) YouNc'~[a~, W. and ]?A~DE, S. C. (1927). "Occurrence of branched hairs in cotton and upon Gossy2ium Stoelcsii." Nature, Lend., t19, 745. (35) Z~tI'rzEv, G. S. (1922-3). "A hybrid between Asiatic and American cotton plants, Gossyl]ium herbaceum L. and Gossypium hirsutum L." Bull. "Al~pl. Bet. Ge.net. a.nd Plant-Breeding, i3, ]32-4. (Leningrad, 1924.)
EXPLANATION OF FIGURES,
Figs. ]-6. The tribe B'[Mopeae.1 ( x 3100.) Figs. 1-2: Malope h'z[fida. Two types, one with 2n=44 and the other with 2n=50. Fig. 3 : Malope hispida. 2~ =44, three pMrs of chromosomes with satellites. Fig. 4: Kilcdbclia Lindemuthi 2n=44, one pair of ehromosmnes with satellites. Figs. 5-6: Kilaibelia vitifolia 2n =44 and n =22. Figs. 7-18. The geuus Abutilon. ( x 3100.) Figs. 7-8 : A. sh'iahtnl. 2~ = 16, one pair of cba'omosomes with satellites and one pair larger than the rest; n=8, side-view of late metaphase. Figs. 9-10: A. umbellalum 2n= 16, one pair of chronlosomes with satellites, and 2,n = 32 (2f + 8 c). Figs. ] 1-12: A. cris'l)Um 2~= 14, the seven niorphologieMIy different chromosomes are marked with nunlbers, and n = 7. Fig. 13: A. gla,ncum n = 14, d iplotene. Figs. 14=15: A. Aviccnnac 2n =42, 1 Where nothing in partienlar is stated in ~ho explanation of the figures the haploid sets of chromosonles are froni metaphases of the first meiotic division, while the diploid chromosome sets are from somatic divisions in root-tips fixed in Navasllin's solution. Illustrations of somatic chroniosomes from roobtil)s fixed in Lewitsky's fixative arc indi- cated by (2f+8c). A. S:~OVSTED 295
two pMrs witch satellites, and n =21. Fig. 16: A. glga~llcum 2~=42, two pairs with satellii~es (2f+8c). Figs. 17-18 : A. indic'a~ 2n =4~2, one pair wi~h satellites, and n=21. Figs. ]9-29. The genera, Abutilon p.p., Wissadula, ~S'pltaeralcca and Mocliola. ( >: 3100.) Figs. 19-20: Abutilon mollc 2n=,12 and n=21. Figs. 21-22: Abutilott, Rcgncllii 2n=42, one pMr wi~h s~tellites and .n=21. Fig. 23: Abulilon sp. 2n=42, two pairs with satellites. Fig. 2~1: A butilo~, sp. 2~=,12, two pairs with satellil,es (2f+ 8c). Fig. 25: [Vissadula contracts 2n = 14-, two pairs with satellites. Figs. 26-27 : S'phaeralcea miniala, n=5 and 2n=10, one pair with satellites. Fig. 28: Sphaeralcea ~tmbcllata 2n=34, one pair with satellites. :Fig. 29: Modiola ,,n.tdt{fida 2n=18, two Fairs with satellites. Figs. 30-36. The genus La~alera. ( x 3100.) Fig. 30: L. arborca 2n =,12, one pair with satellites. Figs. 31-32: L. cachcmiriana 2n =42 and 2n =84, Fig. 33 : L. mm~:rilanica 2n =c. 8-1. Fig. 3,1 : L. cretica 2n =e. 112. Fig. 35 : L. thuri~giaea .*l.=22. Fig. 36: .L. plebeia 2n =43, four pairs with satellites, and one pair with a strong median constriction. Figs. 37-46. The genus Allhaea. ( x 3100.) Fig. 37: A. cannabi.*ta 2n=28. Fig. 38: A. aplerocarpa 2n=42. Fig. 39: A..ficijblia 2n =42, one pair with satellites. Fig. 4:0 : A. Heldreichii 2n =42, one pair with satellites. Fig. ~ll: A. q~icinalis 2n=42. Fig. 42: A. l)all'~da 2n=d2. Fig. 43: A. rosea 2n=42, one pair with satellites. Fig. ~l : A. ]~ybrida 2~t. = 42, ~wo pairs with satellites. Fig. 45 : A. sinensis 2n = 70. Fig. ~I6: A. kragujevace~sis 2n =c. 84 + ~shree fragments. Figs. 47-52. The genus Malva. ( x 3100.) Fig. ~17: M. mosehala 2~ =~2, one pair with satellites. Fig. 48: M..nicaeg~sis 2n = 42, one pair with satellites. Fig. ~9: M. A lcea n=~2, me~aphases from the second meiotic division. ]rig. 50: M. brasilie~sis 2n=c. 112. Fig. 51: M. crispa 2n=c. 112. ]Pig. 52: M. borealis 2n = 76, four pairs with satellites. Figs. 53-57. The genera 8idaleea, Callirho~ and Nal)aea. ( x 3100.) Figs. 53-54: Sidalcea candida 2n=20 and 2n=21. Fig. 55: Callirhog lineariloba 2n =42, two pairs with satellites. Figs. 56-57: Napaea dioiea 2n=28 and 2n=29, one pair with a strong median constriction. Figs. 58-68. The genus Malvastrum. ( x 3100.) Fig. 58: M. ca~)ense 2n=44, one pair wi~h satellites. Figs. 59-60: M. scol)arium n=12, diplotaene, and 2n = 24=. Figs. 61-62 : M. coromandelianu~n n = 12 and 2n = 24. Fig. 63 : M. spicata~a 2n =2,1. Figs. 64-65: M. greenmanianum n = 16, diplolaene, and 2n =32. Fig. 66: M. grossulariaefolium 2n =42. Figs. 67-68: M. limense 2n = 30 and n = 15, metaphases from the second meiotic division. Figs. 69-77. The genera Sida and Anoda. ( × 3100.) Fig. 69 : Sida .arens 2n = 32, one Fair wi~h satellites. Fig. 70 : Sida spinosa, n = 7, metaphases from ~she second meiotic division. Figs. 71-72: Sida rhombifolia 2n = 14 and 2n =28. Fig. 73: Sida acula n=14. Fig. 74: Sida l.riloba 2n=28, one pair with satellites. Fig. 75:Sida vsronicaeJblia n =28. Figs. 76-77: Anoda haslala n = 15 and 2~* =30. Figs. 78-86. The genera Malaehra, Uremia and Pavonia. ( × 3100.) Fig. 78: Malachra alccijblia 2u=56. Fig. 79: 2][alachra ea3)ilala 2n=56, gwo pah's with satellites. Fig. 80: Malaehra J'asciala, 2n=e. 112. Fig. 81: Uremia lobala 2n=28. Fig. 82: Urena s inuala 2n=28. Fig. 83: Pavonia praemorsa 2n=28, one pair with satellites. Fig. 84: Pavonia ,~chiml~eria~na, 2n=28. Fig. 85: Pavonia hc~slala 2n=56, three pairs with satellites. Fig. 86: lOavonia spinifex 2~, = 112, ag least four pairs with satellites. 296 Chromosome Numbe'rs in the Malvaceae. I.
Fig. 87. Malvaviscus sp. 2'n =c. 8,1-. ( × 3100.)
Figs. 88-99. Th~ genus Hibiscus. ( x 3100.) Fig. 88 : H. pl~oeniccus n = l l. :Fig. 89 : Hibiscus sp. 2~ = 24 (2f + 8 c). Figs. 90-91 : H. ccr~z~a- binus n=18 and 2n=36, one pair wi~h satellites. Fig. 92: H. Sabdariffa n=36, showing secondary pairing. Fig. 93: Hibiscus sp. 2n=72, one pMr with satellites. Fig. 94: H. gossypin,us n = l~l, side-view of metaphase. Fig. 95 : H. Trionum n = 28. Fig. 96: H. Parl,:cri 2'~z=34, one pair with satellites. Figs. 97-99: H. Sola'ndra n= 17 sad 2n = 34, and tetraploid tissue with 2n = 68.
Figs. ]0O-ll0. The genus Hibiscus p.p. ( x 3].00.) Fig. 100: H. vit~folius 2n=34., one pair with satellites (2f+8c). Fig. 101: H. cocci'~tc~s 2n = 38. Fig. 102 : H..roseus 2n = 38, one pMr wi~h satellites. Fig. 103: H. lVa:imeac n =~12, metaphases from the second meiotic division showing secondary pairing. Note ~he long distance between the ~wo chrmnosome 1)]~tes corresponding to the small size of the nucleus compared with the pollen mother cell. Fig. 10~l: H. tiliace~s 2n=c. 92. Fig. 105: H. collin'us 2a=c. 92. Fig. 106: H. P,osa-si~te,sis 2~=92. Figs. 107-108: H. Man]hot n=33 and 2~t =66. Figs. 109-110: H. Abcl.,ioscT~ts n=36 nnd 2'n =72.
Figs. 111-116. The genera Hibisc~s p.p., Cie~Tfugosia and Gossypioides. ( x 3100.) Fig. 11 i: Hibiscus ,ficulnsus 2, =78, three pairs with satellites (2f+8c), Figs. 112-113: Hibiscus esculent~s 'n=65 ~nd 2n=130. Fig. 11~: Cie,@ugosi~t Hihlebra'~dtii 2u=22. Figs. l 15-116 : Gossypioides Kirt:ii n = ] 2 and 277 = 24, two pairs with satellites.
Figs. 11.7-125. The genus Gossy2)ium. ( × 3500.) Fig. 117 : G. arid'urn 2n =26, one pair with satellites. Fig. 118: G. ttrmo'urianum 2n =26. Fig. 119: G. Klotz.schianu,~b 2n=26, one pair with satellites. Fig. 120: G. lrilobu~n 2n=26, one pMr with satellites (2f+8c). Fig. 121:6 !. arborcum 2n=26, two pairs with satellites (2f+8c). Fig. 122: G. Sloclcsii 2~.=26, two pairs with satellites. Fig. 123: 6/. anomcdum 2n=26, two morphologically different pail's with satellites (2f + 8@ Fig. 124 : G. barbadc~ss n = 26. l~ig. 125: G. Is,meMos,win 2~z = 52, apparent~ly 26 small and 26 larger chromosomes.