ALBERT

Description: This book was composed after a manuscript left by W. Troll of his work Die Infloreszenzen II, part III, chapter 5, Fischer, Jena, 1969. Part I was published in 1964, part II in 1969. Weberling elaborated and updated this manuscript, describing examples of monotelic families, in the style of W. Troll. Together the three books \xe2\x80\x93 all wrapped in orange covers \xe2\x80\x93 represent a standard work consisting of more than 1700 pages and 1436 figures. The figures are combinations of photographs of living plants, explanatory drawings, and schemes. The drawings especially show good old handwork.\nBecause 20-25 years after the first two volumes this third book will tend to lead its own life, Weberling has included a recapitulation of the principles of polytelic and monotelic inflorescences. There is also a welcome glossary, established in cooperation with D. M\xc3\xbcller-Doblies, in which as a surprise the English translations of the terms are also given. Remarkably, the definitions are not in every case identical to those in the glossary of Weberling\xe2\x80\x99s book Morphology of the flowers and inflorescences.

Description: In order to test the applicability of the telome and the classic theories to the nature of stamens a study was made of flowers in Malvaceae, Bombacaceae, Sterculiaceae, Tiliaceae, and Elaeocarpaceae with respect to their ultimate form, their development, and the vascular course of their androecia. The customary dissecting, clearing, and microtomy techniques were used. A chapter on the interpretation of the vascular bundle course in floral morphology has been added.\nIn each flower the stamens are considered to be arranged in five groups, which may be fused more or less laterally. The groups have a three-trace vascular system the laterals of which may be commissural. Only a few Tiliaceae have ten groups.\nWhereas in most Tiliaceae and Elaeocarpaceae the groups are antesepalous, in Malvaceae, Bombacaceae, and Sterculiaceae they are either antesepalous, antepetalous, or intermediate, depending on the variation of a spiral growth in the floral apex. If there is no such growth the groups are antepetalous. Spiral growth is revealed by an oblique course of the vascular bundle traces and the asymmetrical form of the petals and stamen groups.\nThe stamen groups may have many stamens (Tiliaceae) or bear fewer stamens in a fan-like arrangement, in which case they are called either staminal lobes (Malvaceae and Bombacaceae) or, if they are less welldeveloped, phalanges (Sterculiaceae and many Elaeocarpaceae). Since they have their own group primordia, which show a certain phyllotaxis, the stamen groups are considered to be individual in nature. Moreover, in Bombax and allied genera and in some Malvaceae the apical regions of the staminal lobes originate free and are phyllomic in appearance.\nThree parts can be distinguished in each stamen group: one median upper and two lateral outer parts, corresponding with the three-trace vascular system. The upper part is often formed by a few stamens in Tiliaceae and by a single stamen or a staminodial part in Bombacaceae and Sterculiaceae; in Malvaceae it is reduced. Judging by the sub-group primordia, here called staminal buttresses, the lateral parts are considered to have a certain individuality; in some Malvaceae and very markedly so in Pachira spp. the staminal buttresses arise on the staminal lobes to form the lateral parts of the stamen groups. The parts have many stamens, arranged spatially (in Tiliaceae and Pachira spp.), or fewer stamens occurring as simple rows (mainly in Malvaceae and Sterculiaceae). Between the two an intergradated series of forms can be found, e.g., in Bombax and allied genera and in some Malvaceae. In some cases the lateral parts are formed by a single stamen or even a single theca.\nThe position of the carpels depends upon the position of the stamen groups. The carpels alternate with those regions of the stamen groups the development of which is the most advanced when the carpel primordia arise.\nThe parts of the groups as well as the groups as a whole may formerly have been freer but they have been reduced by congenital fusion and partial incorporation in the main floral axis. Evidence for this interpretation is provided by some Tiliaceae with ten freer stamen groups that may be visible either when mature (Mollia speciosa) or only in an early phase of development (Colona spp.). In Mollia speciosa the antepetalous groups are collaterally double, so that they may be regarded as the lateral parts of triple arrangements. In the Colona spp. the antepetalous groups are obscured during ontogeny by secondary receptacular growth. Moreover, if at the same time reduction occurs in the median line of these groups, their lateral parts are assimilated by the adjoining antesepalous groups. What can happen during ontogeny (postgenitally) may equally well happen (congenitally) before the primordia become visible externally.\nThe stamens may represent slightly flattened syntelomic structures. Depending on the time the division process begins, in Malvaceae and Bombacaceae a monothecous stamen primordium can be more or less deeply divided, forming two equal halves with facing xylem. In Malvaceae this dividing process may operate up to three times in succession; the products of the division are all arranged in one plane. Still further divisions may occur in Adansonia digitata and Durio spp.; in that case the results are arranged spatially, though in Durio not in an adaxial median direction. The mesomes occur either free, especially in Durio, or fused. This successive pairing of mesomes cannot be explained by connation of stamens. Under the influence of reduction superficial division gives rise to a bithecous stamen. Partitioned pollen sacs can be considered as due to imperfect division. The nature of several kinds of sterile extensions has been discussed. In Sterculiaceae and Tiliaceae the stamens of many species are resupinate.\nIn some species the lateral margins of the staminal lobes form only a few sessile thecae (Matisieae). In still others (Fremontia californica, Chorisia and Ceiba spp.) each margin immediately forms a single continuous theca each, the primordial staminal lobes being distinctly foliar in appearance. In this way each entire staminal lobe forms a single flattened bithecous stamen with a sterile apical part and a three-trace vascular system. It is precisely these characteristics that the classic theory regards as primitive in stamens. Moreover, it follows that in Mahales bithecous stamens can be structures of two different ranks.\nConsequently in the androecia of this group of taxa a series of transitions exists between more branched and more foliar formations. In this series reduction operates by the loss of parts, by congenital fusion, by incorporation and by flattening. The androecial parts are neither fully stachyosporous nor fully phyllosporous; they are transitory between the two.

Description: The seeds are inferior. Only in the apical part of the seed the testa is integumental; for the greater part it is chalazal. A thick mesotesta is formed by a matted layer of sclereids. The chalazal part of the ectotesta is richly vascularized. A sheath of inverted vascular bundles occurs on the inside of the chalazal part of the mesotesta. The seeds are albuminous, the cotyledons foliaceous. An inside cavity may make the seeds float in water. The nucellar beak persists in the ripe seed. The endopyle is five-rayed in c.s., the ectopyle is a longitudinal slit.

Description: The flower of Bertolonia marmorata, a small herbaceous plant from South Brazil, is epigynous, pentamerous except for the trimerous gynaecium, pentacyclic and diplostemonous. The ovary is fused to the perianth-tube basally, on cross-section it appears as an equilateral triangle, one corner of which is taken by a locule situated abaxially and epipetalous. The style is terminal, and the stigma simple, but around the style the walls of the ovary, especially their middle parts, extend freely upwards (Fig. 13).\nThe axillary placenta is an awl-formed structure, projecting into the locule rather perpendicular to the pistil axis.

Description: The structure of the seed is based on the massive development of the ovule immediately above the insertion of the outer integument. This may be called endochalazal development, as suggested by F. Bouman (Pers. comm.).

Description: Descriptions are given of the flowers, fruits, and seeds. The petals have basal scales. The pistil is an urceolate structure issuing in 5\xe2\x80\x947 stigmas. In it are two whorls of ovules along the wall, the lower whorl in the same radial planes as are the stigmas, the upper whorl in alternate radii. The pistil wall is entirely covered by nectariferous hairs. There is a peculiar vascular bundle pattern. The ovule is sessile and atropous, the nucellus is beaked, the inner integument terminates into 2\xe2\x80\x944 projections, the outer integument into 2\xe2\x80\x944 lobes. The ovules develop into inferior seeds mainly by proximal growth. Lobes of the endocarp grow around the ectostome. The testa has its hard layer in the middle. The seeds consist of two parts, a hard container containing a free kernel, an air mantle being enclosed. This is probably a swimming device. As, moreover, the fruit is pulpous, the species probably is diplochorous. The results are put against the theory of metamorphosis and the carpel theory. It is thought that this Malaysian plant is a very unusual, possibly ancient, monotype.

Description: The early development (ontogeny) of the carpels of 20 species belonging to 8 apocarpous families was investigated with the scanning electron microscope. The results indicate that on the floral apex a circular or a convex meristem develops into an obliquely ascidiate primordium by unequal growth of its periphery. By further unequal growth it develops into a young carpel. The terminal mouth of a cup becomes the lateral cleft of a carpel. The different forms of the young carpels in different species are defined by the varying degree of development of the adaxial region of the initial meristem and/or its margin on the side of the floral apex. This hypothesis is theoretically evaluated.

Description: This study is a full-sounding prelude to the fundamental work on the morphology of inflorescences, which is being prepared by Prof. Dr. W. Troll of Mainz.\nAll inflorescences in Valerianaceae are understood as modifications of one basic form, the thyrse. It is gratifying to note that forms of inflorescences, described in systematical works as for instance 1) capitate or interruptedly spicate (Plectritis), 2) compound dichasium, dichotomous throughout (cymoid Valeriana spp.), or dichotomously branched inflorescence (Valerianella), 3) \xe2\x80\x98rispig bis fast trugdoldig\xe2\x80\x99 (Phuodendron), in reality all are variations on one theme, the decussate mono-, to pleiothyrse, i. e. a simple to compound inflorescence with a racemous primary axis and cymous lateral axes. The transformations take place first of all by a favoured development of lateral axes on definite heights of the main axis (\xe2\x80\x98basi-mesotoner, akrotoner F\xc3\xb6rderungssinn\xe2\x80\x99) and secondly by the number of flowers developing and the more or less pronounced tendency to form monochasia. Moreover, different forms such as loose panicles, umbels, glomerules, heads and even nearly simple racemes (Aretiastrum), originate by extension or reduction of axes of some or all orders.

Description: In this treatise \xe2\x80\x98De l\xe2\x80\x99Ovule\xe2\x80\x99 Warming (1878) remarked that although the borders of the integuments grow uniformly, very rarely a division into lobes can be observed. He mentioned Symplocarpus foetida (inner integument four-lobed), Lagarosiphon schweinfurthii (outer integument four- or five-lobed) and Juglans regia (two-lobed). Moreover he cited the report by some authors of an occasional occurrence of lobed integuments in a few more plants.\nMore recently Leroy (1955) described bilobed single integuments in Juglans and Platycarya. Boesewinkel and Bouman (1967) demonstrated that these lobes arise as two separate primordia in Pterocarya and Juglans.

Description: Septal nectaries are formed by local regions of later nectariferous epidermal cells on the sides of the carpels at their very base. In order that the epidermal cells may differentiate into nectariferous cells, the carpels which constitute the gynoecium have to develop as separate organs. It was argued that if no septal nectaries develop, this free carpel development does not take place. The nectariferous regions get shaped as nectar containers by dermal fusion of the sides of the carpels surrounding them, by upward growth of the apex, and mostly also by meristematic continuity of part of the ovary wall on the outside. By the latter the level of the openings of the nectaries on the ovary is defined. Septal nectaries in Monocotyledons are considered original.