Lie'5»f'Y FLORAL ANATOMY OF LIMNANTHACEAE D. RAMA DEVI Departmenl of Botany, Kakatiya University, Warangal - 506 009 (Accepted March 1989) The floral anatomy of Ummnthei alba, L. bekari, L.douglasii, L. flacossa tn i Flotrkea proserpinacoides hat been inveitigaled. Certain floral fealurei noi recorded even in recent taxonomic wotlcs have been highlighted. The tepals petali and ilament are lingle traced. The androecium consiiu of ten stamens in Limnanthes and six in Floerkea. They are of two lengths the antipeulous being shorter. The antisepalous stamens bear glands at the base. The androecium is interpreted asdiplostemonous on anatomical grounds. There is formation of a short hypanthium without fusion between the bundles of the adnate parts. The carpels are S- traced The donal carpellary traces are ephemeral in L. alba, L. doughlasii and L. flacossa, while they are suppressed in L. bekari. Judging from the position of the ventral bundles the placentation is interpreted as axile. The gynobasic style is vascularized by the common median lateral bundles. On Ihe basis of the floral anatomical features shared by Limnanthaceae and the families of Cereniales, it is suggested that Limnanthaceae be placed in the order Geraniales, but under a separate sub-order Limnanthineae. Key words: Floral anatomy, Limnanthaceae. The family Limnanthaceae comprises iwo 16, 17, 21,22). The calyx in both genera is genera, namely Limnanthes with 10 species and the gamosepalous with valvate aestivation (Figs. 14, 16, monoiypic (Airy Shaw 1973), placed under 19, 20-22). The polypetalous corolla is contorted in theorderGeraniales(Goldberg, 1986). But ithasbeen Limnanthes (Fig. 20) and val vate in Floerkea (Figs. 21, placed in the order Tropaeolales by Dahlgrcn (1983) 22). The androecium consists of ten stamens in and Young (1981) while Engler &. Prantl (1931) Limnanthes and six in Floerkea. They are of two included it in Sapindales. Except for the work of lengths, the antipctaloiis being shorter (Figs. 20-22). Saunders (1939), there is no information on the floral The anthers are dorsifixed and introrse. The filaments anatomy of Limnanthaceae. The present study deals of antisepalous stamens are glandular at the base (Figs. with the floral anatomy of Floerkea proserpinacoides 15, 17-19). The bases of the parianth parts and the Willd. and Limnanthes alba R. Br. Limnanthes stamens unite forming a short hypanthium from which bekari Howell, Limnanthes douglasii R. Br. and the different parts separate at successive levels (Figs. Limnanthes flacossa Howell. 11-13, 17, 18). The syncarpous gynoecium is 5- carpellary in Limnanthes (Figs. 15, 18, 19) and 2- MATERIALS AND METHODS carpellary in Floerkea (Figs. 16, 17), and is deeply The materials fixed in FAA were supplied by lobed with one ovule in each locule (Figs. 15, 16). Dr. I. L. Wiggins, Dr. Robert Omduff and Dr. G. L. The style is single and gynobasic (Figs. 15-20) with Webster. Conventional methods of dehydration, 5 stigmas in and two inFloerkea (Fig.21). infiltration and embedding were followed. Serial Floral anatomy: The pedicel shows a ring of vascular sections of the flower buds of different ages were cut at tissue in Limnanthes and a core of vascular tissue in a of 8-12 microns thick and were stained using crystal Floerkea(Figfi. 1,2). In Liffi/ia/i/Ziej, the stele expands violet and erythrosin combination. in the thalamus and five sepal and five petal traces arise in close alternating whoris (Fig. 3). The main OBSERVATIONS stele after the emergence of perianth traces is in Floral Morphology: The fiower is pedicellate, the form of a closed ring of vascular tissue in L. alba bisexual, actinomorphic, pentacyclic and hypogynous and L. douglasii (Fig. 4), whereas in L. bekari and (Figs. 15-20). It is pentamcrous in Limnanthes (Figs. L. flacossa it consists of a ring of ten discrete 15, -19, 20) spocies, and trimerous except the bundles (Fig. 5). In Floerkea, the stele breaks into gynoecium which is bimerous in Floerkea (Figs. 14, 6 units in the thalamus (Fig. 6). Three of them Present address : Depu. of Botany Nizam College, Hyderabad. emerge out and function as sepal midribs. The traced condition of the petals, the members of remaining three bundles, expand laterally and form Limnanthaceae resemble those of the above mentioned a closed ring of vascular tissue (Fig. 7). The traces families of Geraniales. for the petals, antisepalous and antipetalous stamens The androecium in Limnanthaceae has been arise in three alternating whorls independently described as consisting of ten or six stamens with no from the main stele (Figs. 7-9). After the emergence mention about the difference in the length of the of the staminal traces, five dorsal carpellary traces stamens (Hutchinson 1973;Cronquist 1981; Goldbei:g are organized in L. alba, L. douglasii and L.flacossa 1986). The present study shows that each stamen is (Fig. 10). These bundles fade away without entering single traced and are of two lengths those of the the ovary wall. After the organization of the dorsal antipetalous whorl being shorter. In this feature carpellary traces inL. alba, L. douglasiiandLflacossa the family closely resembles the families of Geraniales. and after the emergence of the staminal traces in L. Judging from the origin of the staminal traces, the bekari the main stele resolves into 5 bundles along the androecium in Limnanthaceae is interpreted as sepal radii and 5 along the petal radii (Figs. 11-13). diplostemonous, a condition also reported in certain The former function as fused ventral bundles and taxa of Linaceae (Narayana 1964; Narayana & Rao the latter as common median lateral bundles. In 1966) and Humiriaceae (Narayana & Rao 1977). The Floerkea, only four bundles are organized from glands at the bases of the antisepalous stamens are the main stele after the emergence of staminal traces non-vase ularised. (Fig. 14), out of which two function as venu-al bundles and two as common median lateral bundles. At No motion has been made about the basal adnation about this level the ovary separates from the between the perianth parts and stamens in the family hypanthium (Figs. 12, 13, 18). The ventral bundles even in recent taxonomic works (Hutchinson 1973; directly enter the ovules and after traversing the Cronquist 1981; Goldberg 1986). The present study funiculus divide forming smaller branches which clearly brings to light the adnation between the extend into the integument (Eigs. 15-17). The style perianth parts and stamens leading to the formation of shows a cannal lined by transmitting tissue consisting a short hypanthium without the involvement of the of deep staining cells (Figs. 15-20). The common traces. median lateral bundles extend into the common The carpels are 5-traced and a tendency for gynobasic style and terminate at the base of the suppression of dorsal carpellary traces is noticed in the stigmas which present a conduplicate form and family as reported in Oxalidaceae (Narayana 1966). lie along the septal radii (Figs. 15-21). The perianth Judging from the position of the ventral bundles bundles divide to form smaller bundles in the formed by the fusion of homocarpellary ventrals, the respective organs (Figs. 15-22). placentation can be interpreted as axile. While the DISCUSSION ventral bundles are completely utilized in the ovular supply, the common median lateral bundles vascularise The present study on the floral anatomy of the style and terminate below the stigmas. Limnanthaceae bring to light certain details not recorded in taxonomic works. Although the gynoecium is described as 2* or 3- carpellary syncarpous in Floerkea (Hutchinson 1973; In the basically pentamerous and pentacyclic Cronquist 1981; Goldberg 1986), only 2 - carpellary floral plan, the family resembles certain geranialian condition has been met with in all the flowers examined. taxa. However, the peniacyclic flower in is Probably both the conditions occur in the different trimerous. populations of the same species. In the valvate aestivation of the free limbs of Though Limnanthaceae share most of the basic the gamosepalous calyx, the Limnanthaceae differ from and common morphological features such as the other families of Gcraniales, where they are pentacyclic and pentamerous (3-merous in Floerkea) imbricate. The sepals are singliraced as a result of floral plan and essential floral anatomical features suppression of the lateral traces. In the contorted with the taxa of Geraniales, they differ in certain other aestivation of the polypetalous corolla and single features such as valvate aestivation of calyx, sub-basal ovules, integumentary vasculature, gynobasic styJe Goldbeis A l9B6Classifiauion Evolution andPkylogeny and schizocaipic fruit. Despite these differences it of the Families o f Dicotyledons Washington is tentatively suggested that Limnanthaceae be Smithsonian Institution press, pp. placed in Geraniales but under a separate sub-order Hutchinson J 1973 The Families of Flowering Plants Limnanthineae, as has been treated by Takhtajan London Oxford University Press, pp. (1980). However, Maheshwari & John (1956) on Maheshwari P & B M Johri 1956 The moiphology embryologicaJ grounds suggested the creation of an and embryology of Floerkea proserpinacoides independent order, Limnanthaies, for this family. Willd. with a discussion on the systematic position I record my sincere thanks to Prof. L. L. of the family Limnanthaceae, Bot Mag Tokyo 69 Narayana for guidance and Dr. V. S. Raju for valuable 410-423. pp. suggestions. I express my deep sense of gratitude Narayana L L 1964 A contribution to the floral to Dr. I. L. Wiggins, Dr. Robert Omuduff and anatomy and embryology of Linaceae,//ndj'a/i bot Soc Dr. G. L. Webster for the materials. My thanks are 43 343-357. due to Prof. Bir Bahadur, head of the Deparunent, for facilities and the Social Welfare Department Narayana L L 1966 A contribution to the floral (AP) for the award of a fellowship. anatomy of Oxalidaceae / /ap 41321-328.