COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. I. PRUNOIDEAE: PRUNUS

A study of the carpel in 27 species of Prunus has shown certain notable structural relationships associated with the extent of closure of the carpellary margins. These relationships involve the degree of fusion of the 2 integuments, the number of vegetative bundles in the base of the carpel, the extent of fusion of the ovular bundles with one another and with the wing bundles, the relative size of the ovular bundles, and the relative development of the central vascular plexus. The comparative evidence strongly supports a primitively separate state of ovular and vegetative bundles. The significance of this finding is discussed.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE VII. POMOIDEAE: CHAENOMELES,CYDONIA, DOCYNIA

The multi-ovulate pomoids, Chaenomeles, Cydonia, and Docynia, all have closed sutures and extensive fusion between carpel and floral cup and between ovular and wing bundles. Although the ovules in Docynia are generally apotropic and few in number (4–7), the ovules in the other two genera are pleurotropic and numerous (15–48). A statistical treatment of the whole tribe of Pomoideae shows that in carpels with open sutures ovular and wing bundles definitely tend to be separate while in those with closed sutures these bundles tend to be fused. To a lesser degree carpels with open sutures also tend to have bitegmic ovules, separate carpels, and a lesser extent of fusion between carpel and floral cup, while carpels with closed sutures tend to have monotegmic ovules, united carpels, and a greater extent of fusion between carpel and floral cup.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. II. PRUNOIDEAE: MADDENIA,PYGEUM; OSMARONIA

A survey of species of the prunoid genera, Maddenia and Pygeum, and of the genus Osmaronia has been made. The ovules of all are pendent, campylotropous, and epitropic. In the prunoids, the ovular supply is intimately connected with a central vascular plexus in the base of the carpel; that plexus is absent from Osmaronia. The prunoid carpels are marked by an extensive degree of fusion among the ovular and wing bundles, by fusion of the sutural margins, by fusion of the 2 integuments of the ovule to a single massive one, and by the presence of 3 or 5 well-developed bundles in the base. The carpel of Osmaronia also has a strongly fused bipartite ovular supply, separate bundles of which, however, become very much attenuated before reaching the funiculus; it has independent ovular and wing bundles, completely separate carpellary margins, 2 clearly separate integuments in the ovule, and 6 distinctive bundles in the carpel base. At the funiculus, the wing bundle of Osmaronia is connected with the adjoining weak ovular bundle by a well-developed vascular branch. Various particularities in the morphology of Osmaronia lend support to its segregation into a unique tribe, the Osmaronieae of Rydberg.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. III. POMOIDEAE: CRATAEGUS,HESPEROMELES, MESPILUS,OSTEOMELES

The carpels in Crataegus, Hesperomeles, Mespilus, and Osteomeles appear to constitute a morphologically related group: all have bony pits, ovules that tend to be acollateral (usually superposed), and clearly separate ovular and wing bundles, i.e., no “ventral” bundles, at the level of ovular insertion. In species whose carpels have no sutural opening, the integuments are more extensively fused with one another, the degree of intercarpellary fusion tends to be greater, and the carpels are fused with the floral cup to relatively higher levels than in those species whose carpels have a sutural opening. In the few cases in which wing and ovular bundles are adnate at the locular base (Crataegus monogyna, Mespilus, Osteomeles anthyllidifolia, O. Schwerinae), the extent of inter- and extracarpellary fusion and sutural closure is among the most advanced.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. IV. POMOIDEAE: CHAMAEMELES,COTONEASTER, DICHOTOMANTHES,PYRACANTHA

The carpels of Chamaemeles, Cotoneaster, Dichotomanthes, and Pyracantha tend to be separate from one another, their sutures tend to be closed, and they become more or less bony at maturity. However, aside from having collaterally placed ovules, they do not appear to be structurally similar. There seem to be 2 different evolutionary trends in the ovular bundle–wing bundle relationship: in Pyracantha, progressive fusion between the ovular bundle and the wing bundle has led to the formation of a “ventral” bundle; in Cotoneaster, and possibly Chamaemeles, the wing bundle has become reduced and rather attenuated. A primitive pomoid state may be represented by the carpel of Dichotomanthes, which is completely free of the floral cup and in which wing and ovular bundles are separate. Differences in sutural closure appear only in Cotoneaster, and in species of that genus the wing bundles and ovular bundles tend to be fused if the suture is closed, and separate if it is open.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE VI. POMOIDEAE: ERIOBOTRYA,HETEROMELES, PHOTINIA,POURTHIAEA, RAPHIOLEPIS,STRANVAESIA

The pomoid genera, Eriobotrya, Photinia, Pourthiaea, Raphiolepis, Stranvaesia, and Heteromeles, have compound inflorescences and biovulate carpels which become papery at maturity. The carpels of all of these except Heteromeles are fused with one another. There are open sutures in the carpels of Heteromeles, Photinia, Pourthiaea, and Raphiolepis, and in these four genera the extent of fusion of the ovular bundle with the wing bundle is related directly to the state of tegumentary fusion and to the extent of fusion of the carpel with the floral cup. In those species of Eriobotrya and Stranvaesia with closed sutures the integuments tend to be fused, as do the ovular and wing bundles, and the carpels are adnate with the floral cup for a considerable distance; in species with open sutures the integuments tend to be free, the ovular and wing bundles tend to be separate, and the extent of fusion of carpel with floral cup tends to be shorter. In genera with connate carpels the wing bundles of adjoining carpels may also be fused. The greatest extent of fusion occurs in Eriobotrya and Raphiolepis, in which there may also be attenuation and disappearance of the wing bundles above the region of ovular insertion and even reduction and disappearance of the carpellary margin.     

COMPARATIVE MORPHOLOGY OF THE CARPEL IN THE ROSACEAE. V. POMOIDEAE: AMELANCHIER,ARONIA, MALACOMELES,MALUS, PERAPHYLLUM,PYRUS, SORBUS

The carpels of 2 groups of pomoid genera, Amelanchier, Malacomeles, Peraphyllum and Aronia, Malus, Pyrus, and Sorbus, were analyzed morphologically. Open sutures are associated with a lesser extent of tegumentary fusion and ovular bundle–wing bundle fusion than are closed sutures. However, in the genera as a whole (and particularly in Aronia and Sorbus), the extent of sutural closure is inversely related with the amount of intercarpellary adhesion and with the fusion of carpels to the floral cup. In the Amelanchier group and in Malus and Pyrus, ovular- and wing-bundle fusion is directly related with intercarpellary adhesion. Malus and Pyrus have closer structural resemblances with one another than they have with Aronia and Sorbus.     

COMPARATIVE MORPHOLOGY OF THE PRIMARY VASCULAR SYSTEMS IN SOME SPECIES OF ROSACEAE AND LEGUMINOSAE

The structural patterns of the primary vascular systems in some species of Leguminosae and Rosaceae have been determined by tracing the longitudinal course of the vascular bundles in terminal stem segments. These systems are interpreted as consisting of sympodia. Each sympodium is composed of an axial bundle which is continuous through the length of the segment and from which arise trace bundles that supply leaves and axillary buds. A compact arrangement of vascular bundles seems to correlate with the woody habit. Regardless of the degree of compactness of the primary vascular system, the structural identity of the individual sympodia is maintained. The total number of vascular bundles at a particular level is related to the number of axial bundles in the system, the number of traces per leaf and per axillary bud, and the number of internodes traversed by the traces prior to entering a lateral appendage. Shrubs and trees have more vascular bundles than herbs. Data from this study and the literature indicate that the vascular system is predominantly of the open type in dicotyledonous plants which have helically arranged leaves and, further, that in such plants with a 3-trace, trilacunar nodal structure, the number of sympodia coincides with the number of orthostichies (which is also the denominator of the phyllotactic fraction). In open systems leaf gaps cannot be morphologically delimited. Because of the resemblance of the open type of angiosperm vascular system to that of certain gymnosperms, previously interpreted to have evolved from a protostele, we suggest that the eustele of angiosperms is homologous with the stele of gymnosperms. We believe, also, that angiosperms, like gymnosperms, are probably not characterized by leaf gaps of filicinean type. We provide, furthermore, a rationale for the view that the axial bundle of a sympodium is a cauline structure.     

中国蔷薇科绣线菊亚科的演化、分布——兼述世界绣线菊亚科植物的分布

绣线菊亚科是蔷薇科最原始的亚科,共有22属260余种, 包括常绿和落叶两大类群,前者是 原始类型。我国有8属100种,全都为落叶性。本文着重讨论中国各属的起源、演化和分布等 ,同时也概述全亚科植物在世界各植物区的分布等问题。绣线菊属Spiraea是该亚科落叶类群中最原始的属,它在早期发生趋异进化,衍生出形态各异而亲缘关系密切 的不同属,本文阐明了中国各属的系统位置和属间的亲缘关系。通过对我国各属地理分布的 分析对比,属的分布区可归纳为5个类型。对全球绣线菊亚科植物在世界各植物区中的属、种数统计表明,东亚区有8属105种,其中有96个特有种,是该亚科植物分布最多而又最集中 地区,具有在系统发育上处于各主要演化阶段的落叶类型,因此,东亚区是全球绣线菊亚科植 物的现代分布和分化中心,也是落叶类群发生和发展的关键地区。在北美洲,从马德雷区至落基山区一带分布着11属46种,均为特有种,显然北美洲西部也是该亚科植物的现代分布中心,但可能是第二分布中心。南美洲至今保存2个较古老的常绿属,即Quillaja和K ageneckia,基于此,南美洲可能是绣线菊亚科某些常绿属早期分化和发展的关键地区 。中国绣线菊亚科植物在东亚区占绝对优势,有8属82种,其中有62个特有种,分别占该区属 、种和 特有种数的100%、82%、和65%, 这些类群分布最密集地区是在中国喜马拉雅森林植物亚区 中的横断山脉地区和中国日本森林植物亚区的西部,这一带是中国绣线菊亚科的现代分布和多样性中心,很可能是某些属的发源地。由此看来,绣线菊亚科的落叶属可能起源于劳亚古陆。据化石记载,该亚科植物的起源时间可以追溯到白垩纪早白垩世。     

THE COMPARATIVE MORPHOLOGY OF THE CANELLACEAE. IV. FLORAL MORPHOLOGY AND CONCLUSIONS

The morphology and anatomy of 105 flowers representing 13 species and 6 genera of the Canellaceae are summarized. The flowers are borne in axillary or terminal racemes, cymes, or small groups, or solitary, in an axillary or terminal position. The flowers are characterized as follows: bisexual, hypogynous; sepals 3, thick and leathery; petals, 5–12, free or united into tube at base, rather thick, in 1 or 2 whorls and/or spirals; androecium of 6–12 stamens united by their filaments forming a tube, anthers with longitudinal extrorse dehiscence; gynoecium of 2–6 carpels fused by their ventral margins; 2–6 placentae. There are 2 vascular bundles (rarely 3) to each sepal, 3 to each petal (some of the inner petals have only 1), 1 to each stamen and 1 trace to each carpel. The petal and stamen bundles have a common origin. All the data accumulated in this series on the Canellaceae indicate that the correct systematic placement of the Canellaceae is in the woody Ranales, perhaps in a complex with the Myristicaceae.     

THE COMPARATIVE MORPHOLOGY OF THREE CYLINDROPUNTIAS

The three species discussed in this article have at one time been considered congeneric in Grusonia. Present evidence indicates the three are specifically distinct and should be congeneric, but as cylindropuntias in Opuntia. There seems to be no valid reason for retaining the genus Grusonia. Except for branching and decomposition, Opuntia bradtiana and O. santamaria are more similar anatomically and morphologically than O. kunzei is to either of the two.     

十字花科植物花蜜腺的比较形态学研究

十字花科植物普遍具有花蜜腺。通过对该科9族、36属的74种和1变种植物花蜜腺的形态和结构的比较研究,发现它们的内部结构都由分泌表皮、产蜜组织以及维管束(有些种类缺乏)组成。分泌表皮上分布有变态气孔器,为分泌蜜汁的通道。其外部形态多样,花蜜腺的数量、形状、组成和着生位置等在同族的不同属或同属的不同种间都存在一定差异。根据花蜜腺在分布、形态和结构上的差异可将该科植物花蜜腺分为侧蜜腺型,侧中蜜腺型和环状蜜腺型,在三型下又可划分出19个亚型,并对该科各类型花蜜腺的形态演化关系以及各族间的亲缘关系进行了探讨。     

COMPARATIVE STUDIES OF FLORAL MORPHOLOGY OF THE LABIATAE

Hillson , Charles J. (Pennsylvania State U., University Park.) Comparative studies of floral morphology of the Labiatae. Amer. Jour. Bot. 46(6): 451–459. Illus. 1959.—Comparative vascular studies of 39 species of mints from 27 genera reveal 2 basic stelar patterns: those in which the dorsal carpellary bundles are terminal in origin and those in which the dorsal carpellary bundles are basal in origin. Gradations of intermediate dorsal carpellary bundle divergence exist. Steles exhibiting terminal dorsal carpellary bundles are always associated with laminal ovules and are interpreted as being primitive. Marginal ovules are associated with floral steles exhibiting basal divergence of dorsal carpellary bundles and are regarded as being advanced. Adnation of traces seems to be a more reliable character in determining phylogenetic relationships than is connation. On the basis of 3 characters, viz: (1) position of dorsal carpellary bundle divergence, (2) ovule position and (3) degree of concrescence, a phylogenetic series of the 8 sub-families of Labiatae from advanced to primitive is proffered.     

黄连心皮的形态发育及其系统学意义

本文从植物器官的演化方面来探讨黄连属的原始特性,研究证明,该属植物心皮发育归属一类原始开启心皮类型。