THE VASGULARIZATION OF THE CARPEL IN SOME RANALES

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$SASTRI Department of Botany, Andhra University, Waltair, India^ {Received io September 1958) The morphological nature of the earpel has been a favourite subject of discussion among morphologists from$

1 THE VASGULARIZATION OF THE CARPEL IN SOME RANALES BY R. L. N. SASTRI Department of Botany, Andhra University, Waltair, India^ {Received io September 1958) The morphological nature of the earpel has been a favourite subject of discussion among morphologists from time to time. Since Goethe first proposed the foliar view in 1790, several alternative hypotheses have been suggested but none of them explains the nature of the carpel better than the classical view {;iide Fames, 1931 ; Joshi, 1947). In recent years Bailey and co-workers, as a result of their intensive morphological studies in the woody Ranales, have put forward a modification of the classical view (Bailey and Swamy, 1951) which envisages that the carpel is a conduplicate structure and not involute and that the ovules are laminar and not marginal in placentation. The author (Sastri, 1957^) in the course of his morphological studies found ontogenetic evidence in support of the conduplicate view in the following families of Ranales (sensii lato): Annonaceae, Myristicaceae, Lauraceae, Hernandiaceae, Monimiaceae, Berberidaceae, Menispermaceae, Lardizabalaceae, Nymphaeaceae, Ceratophyllaceae and Dilleniaceae. The results are being published elsewhere m detail (see Sastri, i()^ia and 1958ft, etc.). In addition, the author's study has also revealed some interesting features in earpellary vasculature whose significance is discussed briefiy in this paper. The three trace carpel is generally regarded as the primitive type from which on the one hand multitrace condition may be derived by amplification and on the other one or two trace carpels have resulted from reduction (Eames, 1931; Puri, 19si)- Eames (1931), however, expressed the opinion that probably the multitrace condition may be found in some of the primitive families. Since then carpels with more than three traces have been reported in Degeneria (Swamy, 1949); Cercidiphyllum (Swamy and Bailey, 1949); Winteraceae (Nast, 1944); Lauraceae (Kasapligil, 1951; Sastri, 1952); Myristicaceae (Sastri, 1954; Nair and Bahl, 1956); Annonaceae (Sastri, 1957ft); Berberidaceae (Sastri, i957fl); Nelumbium luteum (Saunders, 1939); A^. speciosum (Sastri, 1957^) and Proteaceae (Rao, 1957). F\irther Flames is reported (Vander Wyk and Canright, 1956) to have recently discovered that the carpels of Eupomatia show five to nine traces. It may be mentioned that the increase in the number of earpellary bundles in these species is not due to branching of the dorsal bundle as in Ranunculaceae (Smith, 1926) but is due to origin of additional bundles in an independent manner. It has been argued in the case of Degeneriaceae (Swamy, 1949) and Lauraceae (Sastri, 1952) that the presence of additional bundles probably indicates that the monocarpellary gynoecium in these families has arisen from a multicarpcllary condition, the additional bundles representing those of the missing carpels. Likewise some authors like Mez (1889) and Coy (1928) have interpreted the number of bundles in the pistil as an indication ot the number of carpels in Lauraceae. On this basis the different species of a single genus like Cinnaniomum will have to be considered to be made up of a varying number of carpels since C. iners (Sastri, 1952) has numerous bundles, C. zeylanicum (Sastri, ' Prt'sent address: Department cil Hotany, Unisersity nf Winsconsin, Madison fi, Winsconsin, 306 I'.S.A.

2 Vascularization of the carpel 307 (1957(3) has four bundles and C. serieum (Mez, 1889) has six bundles in the gynoecium. An extension of this argument to the Annonaceae will lead to the obviously erroneous conclusion that each carpel represents a reduced condition from a multicarpellary state. On the other hand, the widespread occurrence of multitrace carpels in a number of primitive families especially Degeneriaceae suggests that this condition represents a primitive state. The assumption that the three trace condition is primitive derives support from Sinnot and Bailey's (1915) conclusion that the 'primitive angiospermic leaf was simple, palmately veined, probably three-lobed and was provided with three main vascular strands which were attached by a trilacunar node'. However, Sporne (1954) remarked: 'The facts of nodal anatomy (Sinnot and Bailey, 1914) are available for only 155 out of 259 families of Dicots and while preliminary calculations suggest that these workers were correct in claiming that the trilacunar node is primitive the conclusion cannot be taken as reliable until the remaining 104 families are included in the calculations.' Recently Bailey (1956) in a reconsideration of the subject says 'it is not possible to assume that the unilacunar nodes in dicots are derived in all cases by reduction from a trilacunar condition. The occurrence in certain dicot families of transitions from unilacunar to trilacunar structures and from pinnate to palmate parallel venation indicates that the evolution of leaf form and venation is not a strictly unidirectional and irreversible phenomenon as in the case of the phylogeny of the angiospermic vessel'. In the light of this, the assumption that the three-trace carpel is the primitive type for the angiosperms as a whole loses much of its weight. It is now therefore suggested that in some families and orders the multitrace carpel might be the basic type and carpels with fewer traces might be derived. It is possible that there are 'several diversified forms of potentially ancestral' carpellary vasculature as suggested by Bailey (1956) in the ease of the angiospermic leaf. Of all the species studied by the author Myristica fragrans (Sastri, 1954) shows a remarkable type of carpellary vasculature. In this, as well as in M. malabarica (Nair and Bahl, 1956), the carpel wall is traversed by a ring of bundles none of which is distinguishable as dorsal or ventral bundle and many of which give oif traces to the inside, which enter the ovule. In addition, the carpellary bundles send out branches to the outside, which ramify through the wall of the gynoecium. Nelumbium speciosiim (Sastri, 1957(2) resembles Myristica in carpellary vasculature, each carpel having numerous bundles none of which are distinguishable into dorsal and ventral bundles and many of which supply traces to the ovule. Saunders (1939) remarked that the carpellary vasculature of Nelumbium luteum is exceptional in being of the palmate type of the foliage leaf. The carpels of Myristica and Nelumbium thus appear to be least specialized in vasculature, there being no structural or functional differentiation among the various bundles. In this connection it may be recalled that Corner (1949) remarked that Myristicaceae is a peculiarly isolated family, being the only entirely arillate family of angiosperms. Sporne (1949) on the basis of statistical correlation came to the conclusion that Myristicaceae is the third most primitive family of angiosperms. Starting from the undifferentiated type (as in Myristica and Nelumbium) it is possible to trace a series of trends of specialization in carpellary vasculature among the Ranales {sensu lato). These are: reduction in the number of carpellary bundles; differentiation of dorsal and ventral bundles in size; origin of ovular vascular supply from both the dorsal and ventral bundles as in Degeneriaceae and Winteraceae (Bailey and Swamy, 1951); origin of ovular vascular supply from the dorsal bundle alone as in Cananga odorata (Periasamy and Swamy, 1956) and Saccopetalum tomentosum (Sastri, 19576);

3 3o8 R. L. N. SASTRI origin of ovular vascular supply partly from the ventral and partly from the lateral bundles as in Cinnamomum zeyhinicum (Sastri, 1957^); and finally the restriction of the function of supplying the ovular vascular traces to the ventral bundles alone as in the majority of dicots. These trends have not progressed synchronously because some species'like Cananga odorata and Saccopctalum tomentosum, though they have reached a three-trace condition, have retained a primitive type of ovular vascular supply. Some species like Uvaria kirkii show transition stages since in this plant though the ovules receive their vascular supply entirely from the ventral bundles, the dorsal bundle also sends out branches which travel along the lamina of the carpel right up to the margin, thus sho\\ing that the latter represent vestigial traces which also once supplied the ovules. Thus the present study has revealed some salient phylogenetic trends in carpellary vasculature, particularly with regard to the vascularization of the ovule and serves to reemphasize the view of Bailey and Swamy (1951) that the orders and families of surviving flora and more particularly the Ranales {sensu lato) retain comprehensive records of phylogenetic changes. ACKNOWLEDGMENTS The author is greatly indebted to Mr. E. J. H. Corner, F.R.S. and Professor Arthur J. Eames for kindly going through the manuscript, though their support is not claimed for the views expressed in the paper. His thanks are due to Professor J. Venkateswarlu for guidance and encouragement. REFERENCES BAILEY, I. W. (1956). Nodal anatomy in retrospect. J. Arnold Arb., 37, BAILEY, I. W. & SWAMY, B. G. L. (1951). The conduplicate carpel of the dicotyledons and its initial trends of specialization. Amer.J. Bot., 38, CORNER, E. J. H. (1949). The durian theory or the origin of the modern tree. Ann. Bot., 13, COY, G. V. (1928). Morphology of Sassafras in relation to phylogeny of angiosperms. Bot. Gaz., 86, EAMES, A. J. (1931). The vascular anatomy of the flower with refutation of the theory of carpel polymorphism. Amer. J. Bot., 18, JOSHI, A. C. (1947). The morphology of the gynoecium. Pres. Add. Bot. Sect. Proc. Indian Sci. Congr., 34th session. Part II, Delhi, KASAPLIGIL, B. (1951). Morphological and ontogenetic studies on Umbeltularia californica Nutt. and Laurus nobilis Lin. Univ. Calif. Pub. Bot., 25, MEZ, C. (1889). Morphologische studien uber die Lnuraceen. Diss. Berlin Verh. Bot. Ver. Brandenburg, 30, NAIR, N. C. & BAHL, P. N. (1956). Vascular anatomy of the flower of Myristica nialabarica Lamk. Phytomorpli., 6, NAST, C. G. (1944). The comparative morphology of the Winteraceae. VI. Vascular anatomy of the flowering shoot. J. Arnold Arb., 25, PERIASAMY, K. & SWAMY, B. G. L. (1956). The conduplicate carpel of Cananga odorata. J. Arnold Arb., 37, PuRi, V. (1951). The role of Horal anatomy in the solution of morphological problems. Bot. Rev., 17, RAO, C. V. (1957). Cytotaxonomy of Proteaceae. Proc. Linn. Soc. N.S.W., 82, SASTRI, R. I^. X. (1952). Studies in Lauraceae. I. Floral anatomy of Cinnamotniim ineis Reinw. and Cassytha fitifoiniis. Linn.J. Indian Bot. Soc, 31, SASTRI, R. L. N. (1954). On the vascular anatomy ofthe female flower oi Myristica fragrans. Proc. Indian Sci. Congr., 41st session (Hyderabad), SASTRI, R. L. N. (19570). Floral morphology and embrj'ology of some Ranales. Thesis approved for the D.Sc. degree of the Andhra Univ. SASTRI, R. L. N. (19576). The vascularization of the ovule in Sacccjpetaluni tomentosum. Curr. Sci., 26, 183. SASTRI, R. L. N. (i958ro. Floral morphology and embryology of some Dilleniaceae. Bot. Noti.<:fr {Lund), III, No. 3,

4 Vascularization of the carpel 309 SASTRI, R. L. N. (19586). Studies in Lauraceae. II. Embryology of Cinnamomum and Litsea J Indian Bot. Soc, 37, No. 2, SAUNDERS, E. R. (1939). Floral Morphology. Vol. II. Cambridge. SiNNOTT, E. W. & BAILEY, I. W. (1914).' Investigations on the phylogeny of angiosperms, I. Nodal anatomy and the morphology of the stipules. Amer. J. Bot., i, SiNNOTT, E. W. & BAILEY, I. W. (1915). Investigations on the phylogeny of angiosperms. V. Foliar evidence as to the ancestry and early climatic environment of the angiosperms. Amer. jf. Bot., 2, SMITH, G. H. (1926). Vascular anatomy of the Ranahan flowers. I. Ranunculaceae. Bot. Gaz., 82, SPORNE, K. R. (1949). A new approach to the problem of the primitive flower. New Phvtol., 48, SwAMY, B. G. L. (1949). Further contributions to the morphology of the Degeneriaceae. jf. Arnold Arb 30, SwAMY, B. G. L. & BAILEY, I. W. (1949). Morphology of Cercidiphvllum. J. Arnold Arb., 30, VANDER WYK, R. W. & CANRIGHT, J. E. (1956). The anatomy and relationships of the Annonaceae. Trop. Woods, 104, 1-24.

SOME time ago, in the pages of this journal. Miss Saunders described

[359] FLORAL ANATOMY OF RIVINA HUMILIS L., AND THE THEORY OF CARPEL POLYMORPHISM BY A. C. JOSHI AND V. S. Benares Hindu University, India (With 6 figures in the text) RAO SOME time ago, in the pages of