429 H E T E R O S T Y L I S M IN OLDENLANDfA UMBELLATA L. BY B I R B A H A D U R Deflartment of J3otany, Osmania University, Andhra Pradesh, India R e m a r k a b l y little is known about heterostylism i n tropical plants, and I know of no studies of natural populations comparable with those of Schoch-Bodmer (1938) on Lylhrum salicaria L., Haldane.(1938) on Primula acaulis and Crosby (I949) on Primula vulgaris. Prof. J. B. S. Haldane suggested that I might make such a study on o n e of the Rublaceae, a family in which heterostyly is widespread , as Darwin (1892) pointed out in his classical hook, The differe~ztforms of flowers on pIants of the same species. The genus Oldenlandia is represented by 200 species (Rendle, 1959) out of which 21 species display dimorphic heterostylism. B r e m e k a ~ p (1952) has monographed the -Aft-lean species of.this genus, in which he has shown the distribution of heterostyly and homostyly. Bremekamp (1956, 1958) reported some more species which are also heterostyledl Oldenlandia umbellata L. shows dlmorphic heterostylism, i.e., two types of flowers occur on separate pIants, conventionally termed as " T h r u m eyed", with short style and long anthers, and "Pin eyed", with long style and short anthers (see Plate t5). OIdenlandia umbellata is common in the neighbourhood and accessible to me. I t is a conspicuous white flowered annual, and a successful weed. At Adigmet (Osmania University Campus) the popu]atiOn was dense over a large area. At I-Iimayat Sugar and M i r a u l a m it was distributed over w~ste land and road sides, sometimes growing in sand or in rock crevices. At 1Narsapur it was not common in lawns, but occun'ed along-dry water courses, confirming Ridley's (t930) statements as to the dispersal o f its seeds by water. T a b l e 1 is a list of all species o f 1Lubiaceae kn.own to m e in which heterostylism has been reported. These number 155 out of a total of about 5,500 species in the family. T a b l e I, S. No. Species 1. *Cinchonamicrantha. 2. Sipania sp. 3. Pentaslanceolata. P. pl~rseglovei. P. ct.eisostoma. P. parviflora. P. arvensis. P. zanzibarica. p. l~ub~'t~ra. p. decao,ana. P. pseudom.agnifica. P. jn~rlmrea. Recorded cases of Heteros~lism i,~ the family .R'ubiaceae Tribe Cinchoneae. Rondeletieae. I-tedvotldeae. ,, ,, ,, ,, ,, ,, ,, ,, ,, '*East (1940): 4.0 ~pecies are heterosilylic, ID Dimorphic, T Trirnorphic. Floral situationJ" References D Darwin (t892), East (1940) Verdcourt (1958) Verdcourt (1953d),Baker (1958), Bir Bahadur (Pin form only) "~lerdcourt (1953c1),Baker (1958) Vcrdcourt (1953d} "Verdcour t (1953d), IIiern (1878) tliern (1878) Verdcourt (1953d) ,, ,, quoted by Verdeourt (1953d) I-Iiern (1878) D T or D D D D D D D D D D I-Ieterostylism in Oldenlandia umbellata 430 Table 1. Recordedcases of Heteros~ylism in thefamily Rubiaceae--((~,ontd,) S. _.No. - SpEcies .?entas nobilis. P . longiflora. 2":'. cocchwa. 4.. 2:'arapentas balllscombei. 2 . setigera. 2 ~. gabonica. 5. ?~plnopentas tat~folia. 7-. ul,~gurica. :'.'_-. cameronica. ',5. J~,:ntodonpentander. P . laurentioides. 7. Dibrachi~zos~yhzs kaessnerL ~. Otomeria gMneensis. O. lanceolata. O. maNensis. O. oculata. 9. t:hamaebenlas greenwayl. O. 5;.'.cosl~erm~ sp. t 1. ,57ephanococcus crepinianus. 12. ..~])moslad~ya s~. !3. I-{edythyrsus sb. J :t'. A gathisanthemum bojeri. A. angolense. A . chtorophyllum A . quadricostatum. !5. .~ionitis s~. i 6. A m p h i a s m a l u z u M d e s . A . redheadii. A. robijnsii. A . bengueUense. A . merenkyanum. :i. di~a~'icatum, ! 7. Lelya osteo~arpa. [8. 2-~&iocraterium verlicillare. t9. 2Dirichletia slZ 20. 2~e~,2anisia sp. 2 I. 57&robombyx kinabdunlsis. 22. D a n a i s sp. 23. 2~oustonia caerule& Floral situation Hedyotideae. ,, D T or D ,, ,, D D ,, T or D ,, ,, , ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, ,, , ,, ,, ,, D D D D D D D D D D D D D D D D D D D D D I) D D D D D D Bremekamp (1.952) Verdcourt (i953c) DOI Bremekamp (1939) Hiern (1878) 9 24. 2~. 26. ,, ,, ,, ,,, ]l, r o, ,, ,, ,, D D D D D ~4~otis nummzdarla. -d. richardiana. Schismatodada grichopharynx. O ldenlandia cryptoca~pa. ,, ,, ,, ,, D D D D Ct. tzervosa. ~ D O. chevaliieri. O. o c e O. aretioides. O. pulvh~ata. O. monanthos. O. hockii. O. geophila. O. frieslorum. O. greenwa)~i. O. j o h n s t o M L O. "ru]~icola. O. rattscosa. O. tenella. O. sipaneoides. O. ta~davdina. ,, l l a t a . Rc.fe• Tribe . ,, ,, ,, ,, ,, ,, ,, ,, ,, , ,, ,, ,, Verdcourt (1953d) quoted by Baker (1958) Verdcourt (1953c) Bremekamp (I952) Verdcourt (I953a) ;J Brcmekamp (1952) sJ ~J Bremekamp (1947a) Verdcourt (I958) Darwin (1892), Stevens (I912), ]Robinson and Fernald (1908), Lewis (I961a) Bond (1953) Verdcourt (1958) Bremekamp (1952) D D D D D D D D D D D D D D D ~z BIa Ba~AI~Ua TabLe S. No. 1. R e c o r d e d cases o f H e t e r o s t S i s m Species Oldenlandia taborensis. O. duemmeri. O. scopulorum. 0 wiedemanii. O. icthyoderma. O. herbacea var. holstli. O. pringlai. O. sax~fragoides. O. rosMala. O. microaa~x. O. q~'inis. O.flosculosa. O. patula. O. umbellata. O. somala. O. eludens. O. marginata. O. oxycoccoides. O. vertidllata. O. filifies. O. aapensis. O. sd~imfieri. 27. Hedyotis sp. H . n~gricans H . humifusa I-Z. purpurea. 28. Bo~tvardia Mantha. 29. Knoxia sp. tO. mollis. K . platycarpa. 30. Cmckshankia gladatis. C. lo,menodon. 3 i. 2-vlussaenda e~ythrophylla, A,ir. degans. M . temdflora. Mussaenda sp. M . chippi 9eo~throphylla 32. Pseudomussaenda stenocarpa. l~.flava. 33. Gouldia s#, 34. Adenm'acme lo~lgi.folia. 35. Aphaenandra unlftora. Aphaenandra sp. 36. Coccocypselum ~p. 37. Pauric{iantha sp. P. hirtella. 38. Sablcea venosa. S. hierniana. 39. Stipularia africana. 40. Ecpoma apocynaceum. 41. Temnopter),x sericea. 42. Pentaloucha sp. 4,3.' ,gacosperma paniculala 44. Anthospermum herbaceum. 45. Coprosma sf~. 4"6. Mitchellarepens. 47. 48. Paederia sp. Tricdysia sp. ,2t 43t i~ the f a m i l y Tribe Florat situation Hedyotideae D ,, ,, ,, ,, ,, ,, ,, ,, ,, D D D D D D D D D ,, ,, D D ,, ,, ]3 D ,, D ,, D ,, D ,, D ,, ,, ,, ,, ,, ,, D D D D D D ,, ,, D D Knoxleae ,, D D D ,, D Cruekshankleae ,, i'vlussaendeae. ,, ., ,, ,, D D D D D D D ,, D ,: ,, D D ,, D ,, ,, , ,, ,, ,, T or D D D D D D ,, ,, ,, ,, ,, , ,, D D D D D D D A~lthospermeae ,, ,, D D D Paederieae Ixoreae D D R'ubiaceae--(Contd.) References B r e m e k a m p (1952) ,, ,, ,, ,, :, ,, ,, , ,, . Bremekamp (I952), Baker (1958) Bremekamp (1952) ,, Bremekamp (1952), Bit Bahadur, .Lewis (1961a) Bremekamp (1952) ,, Bremekamp (1958) ,, Bremekamp (1952) Bremekamp (t956) Post (1932) Crowfoot (1928) Darwin (1892) Lewis (I 961 b) ,, ,, Darwin (I892) Darwin (1892), East (1940) Fyson (1932) Bond (1953) Skottsberg (1915) Verdcourt (1958) Baker (1958) B a k e r ( 1958 ), Hall~ .( 1961 ) Petit (1954) Bremekamp (1947b) Hail6. (196I) ,, Petit (1954); Hall6 (1961) Petit (1954) ~, Darwin (]'892), :Hooker (I882) Bremekamp (1937) t-l"all~ ( 1961 ) Darwin (1892) Verdcourt (1958) I-Ial16 (196I) ,, ,, ,, ,, , ,, ,, Verdcourt (1958) Darwin (1892) Darwin (1892), i%obinson and Fernald (1908) ~Verdcourt (1958) Hiern (1878) 432 Heterostylism in OMenlandia umbellata Tabte I. Recordedcases of Heterostylism in thefamily Rubiaceae~(CcJztd.) s. No. 49. Species Craterispermum lauKmm~. 50. Rudgeajasminoides. J~. coriaeea. (R. erlantha.) 51. Psychotria vogeliana. l~o,cholrla ~b. P, benlhamiana. P. warnecM. P. malyana. P. elongata. 52. Uragoga nimbmm. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. U. peduncularis. Lasianlhzts c@itMazus. l~ap?uria s/~. Grumilea sp. Geophila sp. Borrerie sp. Diodiasp. Spermacoce sp. Selonocera sp. Suteria ssO. Lipostome sp. Schwendenera sp. Perama sp. Nertera sp. 3/Ianettla sp. Tribe Floral situatioa References C,raterispermeae Coussareae ,, D D D Verdcourt (1958) Baker (1956) Baker (1956) "Darwin's (1892) Psychotrleae ,~ ,, D D D Baker (1958) Darwin (1892) Baker (1958) ,, ,, ,, D D D Ernst. (t932) Fyson (1932) SehneI1 (1953) quoted by Baker ,, ,, ,, D D D Baker (1958) Bir Bahachu" (Pin form only) Bremekamp (1961) Spcrmacoceae ,, ,, ,, :, ,, D D D D T D D Baker (1958) (Pin ibrm only) Darwin (1892) Darwin (1892), Baker (1958) Darwin (t892) Willis (193I) Darwin (I892) ,, D East (1940) ,, ,, D D Faramea spY' (1958) D '~ ~ ? D D Darwin (1862) ,, D u r i n g September and December i960, the collections o f plants were m a d e in the localities mentioned in T a b l e 2. As the species is a strict-annual, there was never a n y d o u b t as to What constituted a single ;plant, as there ds in perennials such as P r i m u l a I carried two bags, into one o f which I p u t long styled acauIis and L y t h r u m salicaria. plants into the other short styled plants. T h e counts are given in Table 2. T h e r e is an excess o f " P i n " or long styIed plants, which is highly significant ( 2 ~ = 4 4 . 7 ) . But the different i;opulations are extremely heterogeneous (X~----72.37) a n d it is quite possible that " T h r u m " or short styled plants m i g h t predominate in a larger total sample, as they did in two o f m y six. This inequality or anisopIethy a n d heterogeneity is very different t)om Haldane's (1938) finding in P r i m u l a acaulis. Mention m a y be m a d e o f Faberg~ ( 1 9 5 9 ) w h o recently counted populations o f Oxalis, k trimorphic genus, t i e counted the populations o f Oxalis grandis and O x a l i s suksdo~fii, in which he found anisoplethy as against isoplethy (the equiIibrium condition according to certain theories). His counts are given below (Table 3). T o investigate the mode o f inheritance o f style length, iong and short styled plants Were crossed and selfed in the combinations shown in T a b l e 4. T h e cross P • is more fertile than T • P as deduced from the greater seed set per capsule, Selfing pin a n d t h r u m produced very few- or no seeds. Occasionatly long styled plants set .2-5 seeds. T h u s the incompatibility in t h r u m is absolute, a n d in the case o f pin is relaxed a litt!e. 433 BIR BA~AD~JR T a b l e 2. Counls of'Natural populations of O l d e n t a n d i a u m b e l l a m Locality Pin eyed Thrum eyed Total % of Pins % of Thrums I. Adlgmet . . . . 337 150 487 69.20 30.80 2. s . . . . 146 112 258 56.59 43.4I 3~ Narsapur . . . . 1i 1 133 9 244. 45.49 54'51 4. Falaknuma . . . . 78 120 198 39.39 60;6I 5. Himayat Sagar . . . . 125 I00 225 55.56 44.44 6. S.V.U. Campus . . . . 296 .186 48} 61.41 38.59 57.709 42.291 " O Total . . . . 1,093 801 1,894 Table 3 Species LocaIity t, Oxalis grandix . . . . 2. O. suksrlo~fii .. Southern Indiana ~ .. Oregon 0 v Long styled Mid styled Short styled 1305 661 623 246 453 207 : T o c o n f i r m the s e l f - i n c o m p a t i b i l l t y I isolated 15 l o n g a n d 15 short ~;tyled p l a n t s , b u t n o n e o f t h e m p r o d u c e d seeds, t also 9 inttorescences o f thYum a n d p i n p l a n t s w i t h small b u t t e r p a p e r b a g s , a n d t h u s ~ c o n f i r m e d the i n c o m p a t i b i l i t y . Fruit a~2d seed production bz ~ollhzatlon experiments w~;th T a l e 4i Oldenlandia umbellata Pollination Flowers pollinated Thrmn X Thrum (cross) Average seed set per capsule 5 1 0 80 2 1 . . . . 6 0 0 . . . . 76 5 2 Thrum . . . . 26 23 45.4 Thrum X Pin . . . . 29 26 37.-, . . . . (self) . . . . Pin • Pin (cross) .... Pin (setf) X .. Capsules set T h e m e a n l e n g t h s of styles, a n t h e r s , a n d s t i g m a t i c p a p i l l a e of t h r m n a n d p i n eyed p l a n t s o f 0 . umbetlata are given is T a b l e 5i T h e s t i g m a t i c p a p i l l a e are sm~llter i n t h r u m t h a n p i n , a n d t h ; m m p o l l e n g r a i n s a r e l a r g e r t h a n p i n g r a i n s (Plate t5). :~34 Heterostylism OldenIandia umbellata The mo~l)hology of distyly irz Oldenlandia umbellata~, Table 5. Flower type Pin eyed . in Style length Anther height in mm. in mm. . . Thrum e y e d . . . . . . . Length of stigmatic papillae in/z 2.5 0.8-'t. 130 0.B 2-56 80 I measured _,04J polar arid 2,007 equatorial diameters of pollen grains from 20 plants of each type. PMlen~was taken from developed bud.s and open flowers. Table 6 d~ows the distribution of measurements in microns. Measuremeats were taken ia (~cular micrometer divisions, eauh division being equal to 2.5/~. Table 6. 3/leans and variances of pollen grain diameters in microns Polar diameter Flower type Thrum .. Pin .. .9 .. Equatorial diameter Mean S.E. of mean Standard deviation Mean S.E. of mean Standard deviation 22,165 0'117 3.80 19.239 0.077 2.39 20-769 0-087 2"68 17-450 0.059 0.67 T h e mean volume of thrum and pin pollen grains are respectively about 67,000 and 5_9,000 cubic microns assuming them to be spheroids, and multiplying means, which is not quite accurate. IKowever the i:tlean volume of~a thrum grain is about I99% of that of a pin grain. This is ustially the case in heterostyled plants, and is of course believed to be an adaptation to the need of thrum grains to produce longer tubes. T h e significance of the. differences in Table 6 is high, those of the mearl polar and .'.~quatorial diameters being 9.94 and 18'6 times their standard errors respectively. However, if the mean values tbr different plm~ts differed sufficiently, even such large differences as these could be fortuitous. T h e means for each of the 40 plants were calculated (Tables 7 and 8). They varied a great deal withia each group. Thus the polar diameters of thrums ranged from i0"954-0-14 scale divisions to 7.284-0-18, dmse of pins from 9"044-0'12 t o 7.004-0"15. Given such variation the simplest test of significance is to order the plants in terms of pollen grain size. When this is done we find that of the forty m e a n polar diameters the ten largest l:)elong to t h r u m ptants, of the forty equatorial diameters, the eleven largest belong t o thrums. After this the order is unclear, the smallest polar diameter but one, and the smallest equatorial but three being found in t h r u m plants. This is explicable if about half.the plants produced enough pollen grains which were small for various nongenetical reasons to lower 'their mean values'~ appreciably. T h e probability that the first ten polar diameters should belong to thrum plants if thrums ~ c r e laO likelier to Table Plant No, 435 BAHADUR ]~IR Thrum ,~lants 7 n Polar diameter Mean Range 1 58 I0.95 8-13 1.160 58 15 4 8 3 19 12 2 20 I0 18 t8 I3 11 17 14 5 6 9 7 50 30 50 50 51 10,t3 9,97 9,68 9,42 9,42 9,28 9,17 9,07 9,05 9,00 8.93 8,67 8.55 8-27 8.24 8"02 8'02 7"58 7"28 8-12 8~11 7~12 7-t 1 8-11 6-12 7-12 6-t 1 7-11 7-I1 7-10 5-14 7-10 7-I0 6-10 6-10 6-10 6-11 6-!0 1,769 0-433 1.008 0,501 0,484 1,388 2,233 2~725 0,929 0,87t 0.912 4,990 0-793 0'980 I'768 1"226 1,583 2,360 2,144 50 30 50 5I 44 50 50 60 61 43 49 55 65 59 67 53 52 57 57 . 50 54 53 61 44 59 60 65 52 67 53 52 67 64 . . . . . . . n 7 1 5 13 3 2 20 14 18 6 I6 9 15 19 10 12 17 11 4 8 39 73 21 54 34 45 50" 57 54 40 66 47 49 45 44 56 56 58 34 31 n EquatoriaI diameter Mean Range 8,00 8"52 7,93 7-94 7'71 8.43 7,49 6~60 8"80 7,61 8'81 8,76 7,25 7.51 8,4.6 6,97 6-97 6"96 7"25 6,73 6 -I0 7 -10 6 - 9 7 - 9 6 - 8 7 -10 6 - 9 5 - 8 8 -10 6 - 8 7 -lO 7 -t0 5.5- 8"5 6 - 9 7 -10 6 - 8 6 - 8 6 - 8 6 - 8 6 - 9 Variance 1,075 0,335 0"602 0,423 0,298 0,586 0'475 0.417 0,446 0,426 0,738 0,522 0,841 0"~58 0"307 0"219 0,15I 0,347 0.266 0~757 211, Table Plant No, Variance Polar diameter Mean "~;a Range 9.04 9.03 8.76 8.67 8.65 8,60 8,54. 8,53 8"39 8-36 8-27 8'22 8,16 8,00 8,00 7,83 7,73 7,47 7,43 7.00 7-10 8-12 6-10 6-10 7- 9'5 6-10 7-11 7-10 6-10 7-10 6-10 7-10 6-10 7-10 7- 9 6M10 6-10 5M10 6-10 6~ 9 8, Pfiz fllanls Varlar1?ce n 0.527 0.929 1.567 0"798 0,213 t'080 0,742 0,599 1,215 0,410 1,080 0,415 0"909 0,962 0,242 1,601 1,535 1,749 1'006 0"733 4.0 76 21 53 34 43 55 57 50 39 66 47 49 56 4.f~ 48 56 58 33 31 Equatorial diameter Mean Range 7.56 6.97 7.19 7.15 6"96 6'44 7,I1 7.04 7,36 7,14 6"86 7,05 7,22 6,82 7,t8 6-86 6,52 6"78 7'03 6"55 6 -8 6 -9 6 -8 5 -8-5 5,5-8 5 -8 6 -8 6 -8 6 -8 6 -8 6 -8 6 -8 6 -8 5 -8 7 -8 6 -8 5 -8 5 -8 6 -8 6 -7-5 Variance 0.233 0.323 0.454 0.826 0,375 0.64.5 0.053 0-077 0,198 0-219 0.342 0,506 0,198 0,901 0,064 0~073 0,498 0.620 0,418 0,206 436 Heterostylism in O[denlandia umbellata 30[20[ 1 p r o d u c e large pollen than pins is ~ , or 4 , ~ ' and the corresponding probability 1 T h u s the difference is very highly for the equatorial diameters is ~} of tt~is, or 13,764" significant. However if" only one t]~vt;mt and one pin plant had been c o m p a r e d or even a pair of each, nothing definite could be said. T h u s T h r u m 6 has smaller m e a n polar a n d equatorial din:meters thaJ~ Pin 5, though neither is an extreme variant. S O'I~IMARY A brief review ofheterostylic species ,:,(" R u b i a c e a e has been made. Counts of n a t u r a l populations of the dis@ic OIde~zla~Ji~f umbellam have been m a d e tl-om six Iocalities. O u t of a total of 1,894 plants cO~mc:ed, there were 1,093 long styled p l a n t s a n d 801 short styled plants.. Long and shortstyted planks abe se]! incompatible. Seeds are set only in legitimate crosses. Biometrical data pertaining to the pollen grains of the long and short styled plants has been analysed. Short styled pollen grains are larger than long styled. Measurements of styles, anthers, atad ,:cigma papilIae are also given. ACKNOWLEDGEI~IENT$ I a m very grateful to Prof. J. ]3. S. t:[a[dane, F.R.S., for his continued interest, helpfui suggestions a n d criticism during the course of this work. ~I a m aIso gra-teful to Dr. Ni. Hashim, R e a d e r in Botany, O s m a n i a Univeesity for encouragement a n d guidance. Grateful acknowledgement is also J~.:tade to Prof. M[. R. Saxena, Dept. of Botany, O s m a n i a University for facilities and encouragement. This investigation was aided by a Research Training Scho!arship, (;,}vernment of India, for which the a u t h o r wishes to express his thanks. NOTF, ADDED IN PRO0~ While m y p a p e r was in press, Khoshoo and Bhatia (1963) have found heterostyly- in Hamiltonia suaveoie~zs, 3/I~ssae~zda h~teo/.a, M . frondosa, a n d Leptodermis lanceolata while studying the cytology of the flora of i:he N. W. H i m a l a y a s . REFERENCES B,xi,m~, H. G. (I956). Pollen d[morphism in Lhe Rubiaceae. Evolution, 10, 23-31. BAKER, J-I- G. (1958). Studies in dm rep,2oduetive biology of West African Rub[attar. Jour. PFest. 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Cambridge University Press. *Original not seen. ~B1R ]~AHADUR PLATE 15 Figs. 1-2. Clear mounts of short and long styled flowers of OIdeJffandia umbdlala. Fig. 3. Polten grains from short styled flower.• Fig. 4. Pollen grains fi'om long styIed ttower, x 635. Fig. 5, Stigmatic papilI~'m fi'om short styled flower. X300. Fig. 6. Stigmatic pal~iltae from long styied flower, x300, 439