CONTRIBUTIONS TO THE MORPHOLOGY OF THE NYCTAGINACEAE II. Floral Anatomy of Some Species*
BY H. P. SHARMA (National Botanic Gardens, Lt~cknow)
Received September 15, 1962 (Communicated by Dr. V. Puri, r.A.sc.)
INTRODUCTION THE order Centrospermales has been engaging the attention of the author for sometime past. Investigations in different aspects of the family Nyctagi- naceae were taken up as a part of these studies. Besides, all genera of this family possess a single basal ovule which, like all cases of basal placenta- tion, is of special interest. An earlier communication (Sharma, 1962 a) deals with anatomy of the node and inflorescence of some species. Earlier to this, Joshi and Rao (1934) studied the floral anatomy of four species of this family. Bhargava (1952) recorded some differences with their observations in the case of Boerhavia repanda.
MATER/ALS AND METHODS The present communication deals with six species of the Nyctaginaceae. These are: Boerhavia diffusa Lima., B. repanda Willd., Bougainvillea glabra Chois, Mirabilis jalapa Linn., Pisonia linearibracteata Heimerl and P. acu- leata Linn. Material of Pisonia linearibracteata was obtained from the Herbarium of the Botany Department, Meerut College, Meerut and that of P. aculeata was received from the Government Gardens, Bangalore. The rest were collected locally. Serial microtome sections 6-10/~ thick were cut and stained in both crystal violet-erythrosin and safranin-fast green combina- tions. Flowers clea~ed in lacto-phenol were also dissected under a stereo- scopie binocular and proved extremely helpful.
OBSERVATIONS Boerhavia diffusa.--There are two to three unequal medullary bundles in the centre of the pedicel as also reported by Joshi and Rao (1934) (Text-Fig. 2).
* Major part of this work was carried out at the School ofPtant M'orphol~gy, Mecrut College, Meerut. m 149 150 H.P. SHARMA
These reorganise and form a hollow vascular cylinder with xylem distributed in 5--6 patches. From this five (six in abnormal cases) large tepal cords diverge outward on alternate radii leaving as many vascular patches in between (Text-Figs. 3, 10 and 11). A little higher up the latter expand sideways connecting the outward diverging perianth traces by patches of procambial tissue (Text-Figs. 4 and 10). No mention of these alternating vascular patches has been made by Joshi and Rao (1934). In two instances, these vascular patches gave out well-marked vascular cords for the perianth (Text-Figs. 12 and 13, x). Thus in this case the perianth receives its supply in the form of 10 cords. The procambial tissue presists right up to the top of the lower globose part of the perianth where the five perianth traces show conspicuous swelling and cross-connections (Text-Figs. 14 and 16). In the petalold limb five weaker perianth cords continue up (Text-Figs. 15 and 17). These cords show frequent cross-connections (Text-Fig. 17). A little below the tip they give out two to three diverging veins which end blindly. The main bundle ends in a number of branches within the dorsal spine (Text- Fig. 17). After the departure of perianth traces whatever vascular tissue is left in the pedicel again reorganises into a hollow cylinder from which 2-4 stamen traces diverge out, one for each stamen (Text-Figs. 1, 6, 7 and 13). They continue undivided throughout the filament (Text-Figs. 8, 9 and 13-15). The remaining part of the stele again forms a hollow cylinder in the centre (Text-Fig. 13). This gives off a prominent carpel dorsal trace on one side (Text-Figs. 8 and 18). Nearly half way up the gynophore it (carpel dorsal) expands perceptibly and again contracts further up (Text-Fig. 18). Beyond this region it runs up to the stigma without showing any further change. In the stigma, however, it expands considerably and ends in a broad tracheidal plate (Text-Fig. 19). After the departure of the carpel dorsal the remaining vascular tissue is found to be bilobed. At the level of the carpel dorsal expansion it gives out a small strand on one side which ends blindly (Text-Fig. 18, R). The remaining branch continues up for the ovule. Before entering the ovular stalk it again expands perceptibly (Text-Fig. 18). As it enters the ovule it takes an abrupt turn sideways (Text-Figs. 1 and 18). Boerhavia repanda.--There are two sets of bundles at the base of the pedicel. Of these, two to three are medullary bundles and are surrounded by an outer ring of feebly developed bundles. The former form a hollow cylinder below the receptacle (Text-Fig. 20). This cylinder furnishes the various floral traces while the bundles of the outer ring fade completely with- out taking any part in the floral supply. As/he pedicel expands five perianth Tnx'r-Ftcs. 1-19. Boerhavia diffusa. Fig. 1. Semi-diagrammatic L.$. of a £
After the departure of perianth traces five vascular patches are left on the inner side of the tepal marginal traces. These soon reorganise and form a hollow cylinder from which two to four traces are given out for an equal number of stamens (Text-Fig. 24). There is no branching in the stamen bundles throughout their course in the filament. In one case, however, the filament enlarged considerably just below the anther lobes and the vascular bundle also showed some branching in this region (Text-Fig. 29).
After the divergence of the stamen traces the remaining vascular tissue in the centre rcorganises into a hollow cylinder which breaks up into a carpel dorsal on one side and a small arc opposite to this below the locule (Text- Figs. 25 and 30). A little above its point of origin the dorsal bundle expands slightly and continues unbranched up to the stigma (Text-Fig. 30). Unlike the previous species it does not end in a tracheidal plate. Contributions to the Morphology of the Nyetaglnaceae--H 153
TExT-FIGs. 20-32. Boerhavia repanda and Mirabilis jalapa. Figs. 20-31. Boerhavia repanda. Figs. 20-27. Serial transections of the flower ofB. repanda from base upward. Fig. 20. Show- ing hollow receptacular stele. Figs, 21-23. Five tepal dorsals (P) and five marginais (L) arising. Note proeambial patches arising between tepal dorsals. Fig. 24. Stamen traces (S) arisirg. Fig. 25. Stamen disc separated from the ovary. Fig, 26. Carpel dorsa~l (D) separated. Fig. 27. Porianth supply just before entering the petrloid tul:e. Fig. 28. A petaioid tube cleared, cut and spread out to show the vasculature. Fig, 29. Dorsal spine era cleated perizr, tll lobe showing tepal dorsal breaking up and entering the spine. Fig. 30. A cleared slamtn showing branching in the stamen bundle below the anther lobes. Fig, 31. A cleated and dissected ovary showing ovular supply (O) and carpel dorsal (D). Fig. 32. A portion of tlle petaloid tube of Mirabilis jalapa cleared, dissected a~d spread out to show tl'.e ~ase01atut¢, (L, tepal marginals; SC, stylar canal. Other symbols a8 oxplaired earlier.) 154 H.P. SHhgMA
The remaining vascular arc continues up as a solid bundle in the gyno- phore which, before entering the ovule shows a sideways bend (Text-Fig. 30). Mirabilisjalapa. The pedicel of the flower has about five large central bundles and an outer ring of procambial tissue with xylem differentiated at places. The former divide and give out five bract traces. There is a certain amount of anastomosis between bundles of the procambial ring and the bract traces before they pass out. Higher up the medullary bundles re- organise into a hollow vascular cylinder from which ten perianth cords diverge outward (Text-Figs. 33-35). Five of these occurring opposite the bracts arise at a little higher level (Text-Figs. 33-35). A little higher up all these cords divide into three each, of which the median ones are usually larger (Text-Figs. 35 and 36). Higher up the lateral bundles of each group expand sideways and divide repeatedly giving rise to a large number of minute branches forming more or less a continuous arc (Text-Figs. 37-39). At the level where the stamens differentiate most of the smaller branches start disappearing and ultimately leave five perianth dorsals alternating with three smaller bundles (Text-Figs. 40 and 41). There are further divisions and anastomoses in these in the narrower part of the petaloid perianth tube. A little above the departure of the perianth cords five stamen traces diverge out opposite the upper set of perianth cords (Text-Figs. 37 and 39). These continue upward and each passes into one stamen as the latter sepa- rates from the staminal disk (Text-Figs. 39-41). After the departure of stamen traces the vascular tissue left in the centre reorganises into a hollow cylinder (Text-Fig. 38). One trace from this sepa- rates out on one side to form a dorsal bundle for the carpel (Text-Fig. 39). The remaining vascular arc reorganises into a large solid amphicribral bundle which continues up. I,t becomes perceptibly weak as it takes a sideways bend to enter the solitary ovule (Text-Figs. 39-41). Bougainvillea g'labra.--The pedicel of the flower is supplied by an outer ring of a large number of small and unequal bundles surrounding two large ' medullary' bundles near the centre. Just below the bract a large number of the outer bundles diverge outward and ultimately form the bract supply (Text-Figs. 44-48). The remaining bundles of the outer ring close the gap higher up and unlike other species in this family, proceed upward to take part in the perianth supply (Text-Figs. 44-49). As the bract bundles are differentiating the two central bundles which have their xylems facing each other in the beginning now start opening out on the anterior side and close up on the posterior side. The two ultimately fuse on the posterior side to form a vas- cular arc with its xylem towards the anterior side. In its upward course this /
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TBXT-FIOS. 33-58. Mirabilis jalapa and Bougainvillea glabra. Fig. 33. Semi-diagrammatic L.S. era flower-bud of Mirabilisjalapa. Figs. 34-42. Serial transecticns of tl',e flower of Mirabilis jalapa from base upward. Figs. 34-37. Perianth supply arising. Figs. 38and39. Stamen traces (S) arising. Fig. 40. Carpel dorsal (D) and ovular supply (bilobed) arising. Fig. 41. Shows a big ovular trace. Fig. 42. Ovular trace entering the ovule. Figs. 43-58. Bougainvillea glabra. Fig. 43. Semi-diagrammatic L.S.of a young flower-bud. Figs. 44-52. Serial trans¢cticns of a flower from base upward. Fig. 44. Pedicel showing a hollow vascular cylinder in tl'.e centre surrounded by an outer vascular ring. The vascular arc towards the upper side is the bract supply. Figs. 45-47. Five tepaltraces (P) arising from the medullary vascular ring. Figs. 48-50. Stamen traces (S) arising. Fig. 51. Carpel dorsal(D) and ovular trace(O) arising. Fig. 52. Carpeldorsal passingintothe ovary wall. Figs. 53-55. Serial transections of a flower with only four perianth lobes. Fig. 56. Lower portion of a clealed perianth tube. Fig. 57. Upper portion of the same showing vascular pattern. Fig: 58. Portion ofacleared and dissected ovary to show details of the ovular supply (O). (B, perianth bundles contributed by the outer ring in B. glabra; L, perianth marginal traces; M, topal dorsals. Other symbols as explained earlier.) 156 H.P. SHARMA
arc gets connected to the open ends of the outer ring for some distance. Soon however, the inner arc closes completely to form a hollow cylinder (Text-Fig. 44). At this level the outer ring has five large bundles (Text-Fig. 44). As the thalamus is approached, five perianth traces diverge out from the inner vascular cylinder on radii alternating with the five bundles of the outer ring (Text-Fig. 45). The two sets of bundles ultimately come to occur in the same ring. Thus a transection at this level shows an outer ring of 10 vascular bundles--5 contributed by the inner ring and 5 belonging to the outer ring--besides the central vascular tissue for other parts of the flower (Text-Fig. 46). The bundles contributed by the outer ring continue up, branch frequently and most of the smaller branches ultimately fade away as the lower part of the perianth narrows into the tube (Text-Figs. 42 and 50). The remaining 2-3 branches anastomose among themselves and lose their identity. A little below the limb the five bundles contributed by the medul- lary ring give out smaller side branches which form a network between the adjacent midrib cords (Text-Fig. 51). Further course of the midrib bundles is similar to that of other species. One of the flowers studied had only 4 perianth lobes, with consequent reduction in the number of perianth traces (Text-Figs. 52-54).
After the departure of perianth traces the remaining vascular tissue in the receptacle reorganises into a hollow cylinder and gives out seven to eight prominent stamen traces (Text-Figs. 48-50). Each of these passes out to one stamen and continues unbranched in the filament (Text-Figs. 51 and 52).
The remaining stelar tissue again forms a hollow cylinder. In the gyno- phore it gives out a carpel dorsal on one side which continues up into the ovary wall and gradually fades near the middle part of the stigma (Text-Figs. 51, 52 and 56). The remaivSng vascular arc in the gynophore continues up and a little below the ovular stalk expands prominently (Text-Figs. 5I, 52 and 57). Like other species it enters the ovular stalk with a prominent side- ways bend (Text-Fig. 57).
Pisonia linearibracteata.--The pedicel in this species has four large bundles in the centre surrounded by an outer ring of ill-differentiated vascular patches. The latter soon disappear and take no further part in supplying the floral parts. The inner bundles divide within the receptacular region and give off ten perianth traces (Text-Figs. 59-61). Of these, five alternate ones arise at a little lower level (Text-Fig. 61). All these ten cords pass into the perianth tube and at the level of stamen differentiation they get connected together by ill-differentiated vascular patches (Text-Figs. 62-66). In the ,.,; L~" \M "~ 7 61 ....
~ I 0,5 ' I
TExT-Flos. 59-84. Pisonia linearibrac/eata and P. acuIeata. Figs. 59-68. Seriel transections of a flower of Pisonia linearibracteata from base upward. Fig. 59. Pedicel of a flower with a bract (lower side) and two braeteoles one on eitl',er side. in trarsaeti~n. Figs. 60-62. Perianth traces arising. Fig. 63. Perianth tube differentiatirf. Fig. 64. Carpel showing the dorsal bundle (D). Figs, 65 and 66. Sl~owing vascular l~atctxs L'et~een main periantb bundles, Fig. 67. Showing tepal dorsals alone; otl~e~ bundles havc fade(t. Fig. 68. Tepal lohos separated, Figs, 69-84. Serial transections of the flower of Pisonio aculeata from base upward. Fig. 69. One bract and a bracteole differentiated; the second bracteole tracejust arising. Figs. "/0-73. Perianth traces arising. Figs. 74-76. Stamen traces arising. Fig. 77. Carpel dorsal (D) arising. Fig. 78. Secondary marginals (sin) differentiating and dividing, Fig. 79. Ovular bundle departing. Figs. 80-82. Showing course of carpellary wall bundles° Fig. 83. Showing the ovary wall below the stylar region. Fig. 84. Showing the style. (s~n, soco,adary marginals of the carpel, Other symbols as explained earlier.) 158 H.P. S~AgMA
topmost region of the perianth tube the bundles of the lower set fade away completely, and from here upwards only the first set persists (Text-Fig. 67).
Seven stamens are present here and their vascular supply arises as in other species of the family (Text-Fig. 63). The carpel supply is also similar to that of other species. There is a single carpel dorsal which continues up into the style (Text-Figs. 63-65). Besides, there is a single ovular bundle which directly enters the intended organ. Pisonia aculeata.*--The flowers are bisexual. Each has a single bract and two bracteoles. There are 6-7 stamens and their filaments are united at the base to form a short androgynophore. There is a single carpel simi- lar to that of other members of the family. About the level of the bract and the bracteoles the pedicel of the flower has a hollow vascular cylinder in the centre (Text-Fig. 69). The outer corti- cal ring of the other members of the family is not present at this level. A little higher up five traces from the central cylinder pass outward on alter- nate radii (Text-Figs. 70 and 71). These are soon followed by five groups of three traces each occurring in between the first set of traces (Text-Figs. 71-73). It is to be noted that the lateral traces of the trio arise a little lower than the median ones. There are frequent divisions and anastomoses in these bundles (Text-Figs. 74-82). All these proceed upward, divide and ulti- mately fade away in the perianth lobes. The seven stamens, in this species, are arranged equidistantly. Their supply arises from the reorganised stelar cylinder after the departure of the perianth traces (Text-Figs. 74 and 75). Each stamen is supplied by one trace which, like other species, continues unbranched in the pedicel (Text- Figs. 76-82). The carpel supply is markedly different from that of other members of the family. The vascular tissue left after the departure of stamen traces gives out one carpel dorsal on one side (Text-Figs. 76 and 77). The remain- ing arc breaks up into three parts, the median branch enters the single ovule and the side ones pass into the ovary wall as secondary marginals (Text- Fig. 78). The latter divide almost immediately into two each (Text-Fig. 79). All these wall bundles continue up and two of the laterals disappear in the stylar region (Text-Figs. 80-84).
i i * A few flowers labelled as Pisonia aculeata were received from Bang~Jore. T1-.ese were found to be bisexual. Since Pisonia aculeata is described as having unisexual flowers the identification could not be confirmed. Contributions to the Morphology of the Nyetaginaceae--II 159
DISCUSSION Perianth.--In all the species studied except Boerhavia diffusa the perianth is supplied by two sets of bundles--the respective dorsals and marginals (Joshi and Rao, 1934). In Boerhavia diffusa, however, there is only one set of perianth traces on the dorsal radii and ill-differentiated vascular arcs con- necting the adjacent dorsal bundles. In Bougainvillea even though there are two sets of perianth traces those on the marginal radii are contributed by the outer vascular ring of-the pedicel. As such the perianth, in this species, has been interpreted as having only one set of traces (Joshi and Rao, 1934). In all others the outer ring fades completely away without taking any part in supplying the various floral organs. Joshi and Rao (1934) have con- sidered the ill-differentiated vascular patches between adjacent perianth bundles in other genera of this family as comparable to the outer vascular ring of the pedicel. It will be remembered that smaller vascular patches, one on either side of each perianth marginal, have been observed in Boerhavia repanda and definite traces in these very positions in Pisonia aculeata. It is these side-patches which divide and form the connecting arcs between adjacent perianth bundles. It will be remembered that in Bougainvillea the perianth bundles which represent the outer vascular ring of the pedicel occur on marginal radii. As such the procambial arcs of the perianth in other genera of this family are not comparable to the outer vascular arc of the pedi- cel. In this particular character Bougainvillea is different from all other genera studied. Further, the outer vascular ring of the pedicel fades com- pletely away much below the perianth supply. It cannot, therefore, possibly contribute towards the supply of the floral organs. In view of their position and behaviour the vascular patches alongside the marginal traces in Boerhavia repanda and Pisonia aculeata appear to be the laterals. In Mirabilisjalapa and Pisonia linearibracteata these, it appears, get fused with the respective marginals and separate therefrom only when the latter, along with the dorsal traces, divide profusely to give rise to a large number of ill-differentiated vascular patches between the adjacent perianth bundles. In Boerhavia diffusa even the marginal traces get reduced in not arising as definite cords. This is supported by the fact that in young buds of this species definite vascular traces have been seen to arise on marginal radii, which expand and divide to form the connecting procambial arcs. Further, Joshi and Rao (1934) have found these arcs differentiating into single larger traces, flanked by a smaller one on either side, on perianth marginal radii in the fruiting stages of B. diffusa exactly as it would be if the marginals and laterals were present from the very beginning. This clearly 160 H.P. SHARMA shows that, in this species, the respective marginals and the laterals differ- entiate only in later stages and supports the above conclusions. In all the species studied the laterals or their division products continue only up to the top of the lower globose part of the perianth (anthocarp). Bhargava (1952) reported splitting of perianth dorsals in Boerhavia repanda within the anthocarp region. This has not been confirmed by the present study. However, splitting of dorsal bundles in the region of the petaloid limb is quite common. Near the tip of the tepal the midrib bundle breaks up into a large num- ber of minute branches as it enters the dorsal spine. Similar spines are com- mon in many other Centrospermalean families as well. In Ficoidaceae a large amphicribral bundle enters the dorsal spines (Sharma, 1962 b). An un- usually large supply and its amphicribral nature in Ficoidaeeae and division in Nyctaginaceae show that in all probability these spines are comparable to the petioles of a vegetative leaf and the flattened portions of the tepal to the flattened leaf bases quite common in the vegetative leaves of these families. The presence of a ring of vascular bundles in the sepal corniculus of the Passi- floraceae was made the basis for suggesting a petiolar nature of these structures by Puri (1947). The apparent sepal in this family was, however, interpreted as stipular in nature (Puri, 1949). Androecium.--Jostfi and Rao (1934) reported origin of stamen traces in two whorls, one above the other, in the case of Bougainvillea spectabilis. In B. glabra now studied the 7-8 stamen traces arise in five groups alternating with perianth dorsals. Two to three traces among these arise singly and the remaining ones in pairs. It thus appears that the two staminal whorls considered by Joshi and Rao (1934) as the original condition for the family have come to occur together as in B. glabra as a first step towards complete suppression of one of the whorls. In the two species of Pisonia also the stamen traces arise in one whorl. Gynoeceum.--In Pisonia aculeata the carpel wall is supplied by a dorsal and two secondary marginals. In all other species there is only the single dorsal which in B. diffusa ends in a broad tracheidal plate in the stigma region. The single-trace carpel wall thus appears to be a result of suppres- sion in the secondary marginals. Lam (1948 and 1950) considered Centrospermalean families as stachyo- sporous. This view has been criticised by Eckardt (1954 and 1955). In a subsequent paper Lam (1955) suggested that the order may be a mixed one, both phyllosporous and stachyosporous families occurring within the group. Contributions to the Morphology of the Nyctaginaceae--II 161
The entire argument is based on the supposition that in families with basal placentation the single ovule is a direct continuation of the axis [Bhargava (1932), Maheshwari (1929) and Cooper (1932) also considered the ovule in these species as ' cauline ']. As a single ovule arising from the ovary base is a common feature throughout the family, it will be worthwhile to consider the ovular supply in these species in some detail. In all the species studied a large vascular arc continues up from the receptacular stele and organising into a large amphicribral bundle enters the ovule with a sideways bend. A similar bend was observed in Boerhavia repanda by Bhargava (1952). This clearly shows that the single ovule in this family is not a terminal structure. Furthermore, in Boerhavia diffusa the ovular bundle gives out small xylem elements towards the centre which end blindly. This evanescent tissue is obviously the ' residual ' axial supply. This also shows that the tip of the floral axis lies to one side of the ovule and hence the latter is really a lateral organ. In fact the ovule in mature flowers of Mirabilis jalapa is not exactly basally borne but occurs slightly to one side of the median line (Text-Fig. 33). There is, thus, little evidence to believe that Nyctaginaceae is a stachyosporous family. This holds good for other families of this order investigated so far as well (Eckardt, 1954 and 1955; Sharma, 1958 and 1962 c). In Bougainvillea glabra the ovular bundle expands markedly soon after its origin. In Mirabilisjalapa, on the other hand, the ovular bundle becomes perceptibly weak as it takes a sideways bend. It appears, therefore, that the lower portion of the ovular bundle, in these species, incorporates the ' residual' supply of the floral axis. Similar is the case in Boerhavia diffusa. In this particular species the ovular bundle expands conspicuously a little above the sideways bend. This is explained by assuming that the ovular bundle, in this species, is contributed by both the ventral bundles at least up to this level. Examples where more than one ventral contribute towards the ovular supply are found in other families too (see Purl, 1951). The placentatiotL--The placentation in this family has generally been described as basal (Joshi and Rao, 1934). The vascular supply of the ovule, as seen here, shows that the present single ovule is, in all probability, the only surviving member of an original marginal placentation. The placentation in this family, therefore, is better described as sub-basal (see Puri, 1952). SUMMARY Floral anatomy of six species of the Nyctaginaceae has been studied. There is only one set of five perianth traces arising from the central stele in 162 H.P. SHARMA
Boerhavia diffusa. Ill-differentiated vascular patches on marginal radii have also been seen to arise from the stele in this species. The procambial arcs between perianth midribs are contributed by these patches. In other species the perianth receives two sets of traces--the dorsal and the marginal cords, Marginal cords in Bougainvillea glabra arise from the outer vascular ring of the pedicel. Smaller vascular patches, one on either side of the marginal cords, have also been seen to arise from the stele in Boerhavia repanda and Pisonia acu- leata. These have been interpreted as lateral traces. It has been suggested that in other species the laterals arise fused with the marginal cords. The ' procambial' arcs between adjacent perianth bundles, in all species studied, are contributed by the laterals dividing repeatedly and are, therefore, not comparable to either the marginals of Bougainvillea or to the outer vascular ring of the pedicel. The division of dorsal bundle in the tepal spine in Nyctaginaceae and an unduly large amphicribral bundle in Ficoidaceae suggests that in these families the dorsal spine is comparable to a petiole and the expanded portion of the tepals to the sheathing bases of a vegetative leaf. In Bougainvillea glabra and both species of Pisonia the 7-8 stamen traces occur in one whorl. A single large amphicribral bundle forms the ovular supply in all the species studied. In Boerhavia diffusa this gives out xylem elements towards the centre which fade away without supplying any organ. This has been interpreted as the 'residual' stelar tissue. In Mirabilis jalapa the ovular supply contracts a little above the side- ways bend and in Bougainvillea glabra it expands below the ovular stalk. This shows that the lower part of the ovular supply in these species incorpo- rates the 'residual' stelar tissue as well. The course and behaviour of the ovular supply suggests that the ovule is laterally borne in this family and is possibly the only surviving member of an original marginal placentation. Hence the placentation here is better described as sub-basal. There is little evidence to consider Nyctaginaceae as ' stachyosporous '.
ACKNOWLEDGEMENTS The author is extremely grateful to his teachers Professors K. N. Kaul and V. Puri for their keen interest in this work. To the latter he is further Contributions to the Morphology of the Nyctaginaceae--H 163 indebted for guidance and facilities of work provided to him at the School of Plant Morphology, Meerut College, Meerut.
REFERENCES
Bhargava, H. R. .. "Contributions to the morphology of Boerharia repanda," d. lndian bet. See., 1932, 11, 303-26. .. "The Anatomy of the flower of Boerharia repanda,'" Amer. Midland Nat., 1952, 47, 508-12. Cooper, D. C. .. "The anatomy and development of the floral organ~ of Bougainvillea glabra," Amer. J. Bet., 1932, 19, 814-22. Eckardt, Th. .. "Morphologische und systematische Aus~erdung der Placentation von Phytolaccaceen," Ber. Deut~ch. Bet. Ges., 1954, 67, 113-28. .. "Nachweis der Bluttburtigkeit (Phyllosporie) grundstundi- ger samenanlagen bet Centrospermen," 1bid., 1955, 68, ] 67-82. Joshi, A. C. and Rao, V. S. .. "Vascular anatomy of the flowers of four Nyctaginaceae," J. Indian bet. Soc., 1934, 13, 169-86. Lain, H. J. .. "A new system of the Cormophyta," Bluraea, 1948, 6, 282-89. .. "Stachyospory and phyllospory as factors in the Natural system of the Cormophyta," Svenska Bet. Tidskr., 1950, 44, 517-34. .. "Comments on two charts relative to the phylogeny of the Cormophyta, with some remarks of a general nature," Acta Botanica Neerlandica, ]955, 4, 410-28. Maheshwari, P. •. "Contributions to the morphology of Bcerhavia diffu~a-- I," J. Indian bet. Soc., 1929, 8, 219-34. Puri, V. .. "Studies in floral anatomy--IV. Vascular anatomy of the flower of certain species of the Passifloraceae," Amer. J. Bet., 1947, 34, 562-73. .. "The role of floral anatomy in the solution of morpl-.c- logical problems," Bet. Roy., 1951, 17, 471-553. .. "Placentation in Angiosperms," Ibid., 19_'2, 18, gCT-.H. Sharma, H. P. .. "Morphological studies in the order Centrospe~malcs," Agra University Ph.D. Thesis, 1958 (unpublished). .. "Contributions to the morphology of Nyctaginaceae--]. Anatomy of the node and inflorescence of some species," Prec. lnd. Acad. Sci., 1962a, 56, 35-50. .. "Studies in the order Centrospermales--]lI. Vascular anatomy of the flower of some species of the family Ficoidaceav," 1bid., t962b, 56, 269-85. •. "Contributions to the morphology and anatomy of Basella rubra Linn." Bull. Bet. Soc. Bengal, 1962c, 15 (in press).