舞花姜花部维管束系统的解剖学研究

对舞花姜(Globba racemosa)花部维管束系统进行解剖学观察分析,以探讨其缺失雄蕊的去向及其唇瓣和腺体结构的属性.结果显示:(1)舞花姜花梗部的维管束分散排列在基本组织内.(2)子房基部的维管束排成2部分,中央区为分散排列的小维管束,外方为一轮大维管束环,且外环维管束发育为子房壁维管束,心皮背束和隔膜束均起源于中心区维管束,二者的分支在延长部形成一个维管束网结;在网结之上,近轴面的两束心皮背束分支分别进入到2枚侧生退化雄蕊中并成为其主束,远轴面心皮背束的内方分支则成为唇瓣中束,三束心皮背束的其余分支均上行入萼片.(3)唯一1枚功能雄蕊接受近轴面隔膜束的内方主支作为其主束,远轴面2枚隔膜束的主支最后进入唇瓣的两侧束,三束隔膜束的外分支均发育为花瓣束.研究认为:舞花姜的唇瓣是一个三重结构,其中央维管束代表1枚外轮雄蕊,两侧维管束则分别代表2枚内轮雄蕊;舞花姜的2枚花瓣状退化雄蕊与唇瓣的中央一起构成外轮雄蕊,唯一1枚可育雄蕊和唇瓣的两侧同属内轮雄蕊.本研究结果支持姜科子房延长部形成的腺体属于子房上部心皮边缘的维管化附属物的观点.     

粉美人蕉花部维管束的解剖学研究

为探讨粉美人蕉(Canna glauca‘Erebus’)缺失雄蕊的去向和唇瓣的属性,对粉美人蕉花部维管束系统进行了解剖学观察分析。结果表明,粉美人蕉花梗横切面呈椭圆形,中心区的维管束聚集成6束大的维管束,形成心皮背束和隔膜束。在子房区顶部,3个隔膜束各分成3束,外方分支分别进入相应的花瓣,成为花瓣的中束。近轴面隔膜束内方的2束分支进入功能雄蕊。远轴面右侧的隔膜束内方2分支进入唇瓣,发育为唇瓣的部分维管束。远轴面左侧隔膜束内方分支进入内轮退化雄蕊。在花瓣形成时,近轴面左侧心皮背束分成2束,外侧分支进入近轴面外轮退化雄蕊,内侧分支进入功能雄蕊。近轴面右侧心皮背束外方分支进入侧生退化雄蕊。远轴面心皮背束分为2束,1束进入远轴面外轮退化雄蕊并迅速消失,另1束进入唇瓣,继续发育。从维管束来源角度证明了粉美人蕉退化雄蕊的同源异形现象。     

兰花蕉花的形态解剖学

兰花蕉（Orchidantha chinensis)的子房室顶部闭合后向上延长成延长部,实心,但有花柱沟和隔膜蜜腺管通过,隔膜蜜腺管,可分为中央蜜腺管和三条侧蜜腺管;中央蜜腺管位于三个心皮连接处,自子房室区下部产生,向上于延长部的部顶端终止;三条侧管分别位于两个心皮连接处,于子房室区近中部产生,开口于花柱基部。兰花蕉子房室区与延长部均具6枚雄蕊的维管束系统,即3枚心皮背束的伴束与3枚隔膜束,近轴面1枚事膜向上进入唇瓣的维管束系统,位于唇瓣的中央,致使兰花蕉仅具5枚功能雄蕊,唇瓣具双重结构,本文还讨论了兰花蕉科的系统发育位置。     

小草蔻花部维管束系统的解剖学研究

小草蔻花梗的维管束可分成外环和中心区两部分。进入室下区后,外环维管束向外偏移,其数目由约13束增加至约40束;中心区由不规则分布的18束变为三角形排列的12束。延伸至子房室区时,外环基本不变,而原来中心我的维管束则成为3束心皮背束、3束隔膜束及5－7束小的胎座维管束。3束心皮背束外方的主支经延长中最后进入花萼、胎座维管束于延长部基部消失。及至延长部基部,3束隔膜束的内侧横向分支,并最后与部分外环的维管束及心皮背束方的细小分支在此形成一个维管束网结,而外侧的主支直接向上延伸;近轴面的隔膜束主支分裂成4支最后进入仅有的1枚功能雄蕊,无轴面的2束隔膜束主支则各分成2－3束最后进入唇。延长部的维管束网结部分延伸入花瓣、唇瓣和腺体基部,少量进入花柱。首次提出姜科植物的花萼既代表了3枚花萼片,又包含了3枚缺失的外轮雄蕊。支持姜科的唇瓣代表了两枚缺失的内轮雄蕊及两枚腺体是隔膜腺变异结构的观点。     

金嘴蝎尾蕉花部维管束系统的解剖学研究

利用石蜡切片技术对蝎尾蕉科代表植物金嘴蝎尾蕉（Heliconia rostrata Ruiz＆Pavon）的花部维管束系统进行了解剖学研究。结果表明,心皮背束在延长部的基部分裂为内外2分支,内方分支与胎座维管束汇合后进入花柱,远轴面2枚外方分支在延长部的顶部分裂为2～4束进入远轴面2枚外轮雄蕊,而近轴面1枚外方分支则进入退化结构成为其中脉;隔膜束在延长部顶部亦分裂为3～5束,最终分别进入3枚内轮雄蕊;子房壁其它维管束最终进入花被片。本研究认为金嘴蝎尾蕉花部花瓣状退化结构与另外2枚外轮雄蕊具有完全相同的维管束系统来源,应属于雄蕊成员,且支持Kress关于蝎尾蕉科是姜群的姊妹群,区别于芭蕉群其它3科的观点。     

姜花(Hedychium coronarium)花部维管束系统解剖学研究

姜花(Hedychium coronarium Koen.)花梗横切面整体轮廓呈椭圆形,可分为表皮、基本组织和维管束。维管束在基本组织中呈内、外两部分排列。内部维管束联结成网,形成明显外移的三束心皮背束和内方与心皮背束相间的三束隔膜束。至子房室区,心皮背束继续外移,其中主支进入花萼中脉;小分支内移,与内方一轮维管束联结,后来进入唇瓣中央及2枚侧生附属物。在花萼形成的同时,远轴面的两个隔膜中各形成一个上位腺体;同时两束远轴面隔膜束向外、两侧分别形成3束大分支,外方大分支继续外移成为2枚远轴面花瓣中脉,两侧大分支与原外方内移的子房壁维管束集合成一相连的环状维管束网,后进入唇瓣两侧;近轴面隔膜束形成3枚分支,外方分支成为近轴面花瓣中脉,两侧分支进入可育雄蕊。探讨了侧生附属物和唇瓣的来源,支持子房延长部形成的腺体为隔膜蜜腺的变异结构的观点。     

鸭跖草花部维管束系统解剖学研究

鸭跖草花梗项部的维管束分布在中央的基本组织内。自花梗顶部至子永恒基部,维管束系统发生复杂的变化。6枚向外偏斜的维管束发生内外或左右分支,其中3枚维管束发生内外分支,其外侧的3个分支进入萼片成为萼片给管束系统,内侧3个分支进入3枚外轮雄蕊而成为外轮雄蕊维管束;另3枚维管束先发生内外分支,接着外侧3分支发生进一步的左右分支,各形成3－5个小分支,最后进入花瓣成为花瓣维管束系统,而内侧的分支则不再细分,最后伸入3枚内轮雄蕊,成为轮雄蕊维管束。另6枚近圆束形的维管束一直在中央向上延伸,进入子房屋区后,其中3格言 进入子房壁,成为3束心皮背束,最后3束心皮背束进入花柱成为花柱维管史,另3枚聚向中央,成为胎座维管束,胎座维管束至子房屋顶部时消失。文中对跖草及其有关类群的花部维管束系统的来源及演变进行了比较、讨论。     

大鹤望兰花部维管束系统的解剖学研究

大鹤望兰梗横切面近三角形,花梗的维管束分散公布在基本组织内。室下区的维管束大致排列三两部分,外方为一到两环维管束组成的外维管束环,中央为分散排列的中央维管束区。前者的维管束进入子房避讳,后者的维管束进入子房的中轴,形成从维管束。至延长部后,胎座维管束逐渐消失。子房壁上的维管束较易识别的有心皮背束、心成背束伴束和隔膜束。３束心皮背束经处长部最终进入花柱。３枚心皮背束伴束最终分别进入一枚１２上轮雄蕊。     

红蕉花部维管束系统的解剖学研究

红蕉花单性、同株 ,雄花与雌花花梗部的维管束均可分为外环维管束、中环维管束及中央维管束区。雌花外环维管束逐渐外移 ,并分支、变小、数目增多 ,至子房室区中部时几乎贴近表皮 ;中环维管束与外环维管束形态基本相似、稍大 ,至延长部中上部时与外环维管束合成一轮 ,最后进入花被片 ,成为花被维管束系统 ;中央维管束区在花梗部时排列为六组 ,组间有一些小的维管束分布。在室下区 ,近轴面隔膜维管束组消失 ,至子房室区基部时 (室下区 )其它五组逐渐聚集成明显五束 ;而组间的小维管束向中央聚拢 ,于子房室区基部时排列成环形 ,接着进入子房室中轴成为胎座维管束 ,随后束形变小 ,且随子房室的变小而外移 ,经延长部最后进入花柱 ,与心皮背束内方的三枚分支一起成为花柱维管束系统。三束心皮背束延伸至延长部时均分裂为内、外两支 ,三枚外方的分支进入三枚外轮雄蕊。两束远轴面隔膜束进入两枚内轮雄蕊。雄花与雌花的维管束系统基本相似 ,差异主要在雄花无子房室区及中轴的胎座维管束消失。     

圆瓣姜花花部维管束解剖及其系统学意义

用石蜡切片技术研究了圆瓣姜花(Hedychium forrestii Diels)的花部维管束系统解剖结构,探讨了同源异形的各轮花器官维管束来源和属性.结果表明,圆瓣姜花的2枚花瓣状结构为外轮雄蕊成员;唇瓣是三重结构,其中脉源十1枚外轮雄蕊维管束系统,两侧脉源于2枚内轮雄蕊维管束系统;上位腺体为隔膜蜜腺.本研究支持Thompson和Gregory关于姜科唇瓣是三重结构的观点;与其他姜科植物一样,圆瓣姜花子房延长部形成的上位腺体属于隔膜蜜腺而不是雄蕊成员.与已研究过的姜花属植物比较,姜花属花器官维管束系统的来源与走向是一致的,同源异形现象在姜花属植物花的进化中扮演极为重要的角色,可为解释花器官属性提供重要线索.     

Floral vasculature and ontogeny in Canna indica

The identity of the labellum is a hot point in Zingiberales, which has long been discussed by many authors. In this study, floral vasculature and ontogeny of Canna indica (Cannaceae) was observed by LM and SEM in order to ascertain the identity of the labellum and the functional stamen of this species and provide evidence for the homologies of the floral organs in Zingiberales. The results indicate that the labellum of C. indica have incorporated two androecial members from both outer and inner whorls, rather than three, one or half member, as previously suggested by morphologists of Cannaceae flowers. The two labellum traces are here interpreted as: one from the outer androecial whorl (diverging from the carpellary dorsal bundle), while the other from the inner androecial whorl (diverging from the parietal bundle). The functional stamen also incorporates two androecial bundles, the same as the labellum: one trace from the carpellary dorsal bundle, and the other (the petaloid appendage) from the parietal bundle. In addition, the origin of the vascular system in the androecium of Zingiberales and its systematic significance are discussed.     

Floral vasculature in Alpinia hainanensis in relation to the nature of the labellum in gingers

Observations presented here on floral vasculature in Alpinia hainanensis indicate that the labellum incorporates elements of five androecial members rather than two or three, as suggested by previous authors for Zngiberaceae flowers. The pedicel contains an outer ring and a central region of vascular bundles. Three carpellary dorsal bundles (CDs) and three alternatively arranged parietal bundles (PBs) separate from the central region successively. The remaining bundles of the central region run upwards and become the placental bundles to supply ovules. The placental bundles terminate between the top of the locular region and the base of the prolongation. The three PBs divides into about five strands respectively. Of which the outer strand enters into the petal being its midrib and the remaining strands move into the stamen adaxially being the vasculature of the functional stamen and the labellum abaxially being the lateral strands of the labellum. The three CDs divide into about five traces, of which the outer strand becomes the midrib of each sepal and the inner strand runs into the style. The remaining traces re‐unite, re‐divide again in the course up and the two adaxial sets of carpellary dorsals finally enter into the labellum being the marginal traces of it while the abaxial single strand enters into the labellum being its midrib. The two antero‐lateral glands receive small traces without lignified tube elements from the vascular plexus, which fonn in prolongation from both PBs and CDs and a few small strands in the ovary wall. There are no subulate appendages differentiated in the flower of Alpinia hainanensis. Hereby, the median of the sepals, both the marginal portions and the median of labellum, and the style have the same origin in vasculature from the CDs and so do the stamen, the lateral portions of labellum and the median of the petals from PBs. The labellum is supposed to represent three members of the outer androecial whorl by its two marginal portions and the median and two members of the inner whorl by its two lateral parts except the median.     

MORPHOLOGICAL STUDIES IN ZYGOPHYLLACEAE. I. THE FLORAL DEVELOPMENT AND VASCULAR ANATOMY OF NITRARIA RETUSA

The floral development and vascular anatomy of Nitraria retusa were investigated in order to understand its characteristic androecium of 15 stamens and to clarify the systematic position of the genus relative to Zygophyllaceae. Sepals arise in a helical sequence and are relatively small at maturity. Petals are initiated almost simultaneously or in a rapid helical sequence. Five stamen primordia arise opposite the sepals. Next, two other antesepalous primordia are incepted centrifugally to the first primordia on the remaining receptacular surface. The outer stamens tend to be squeezed between the petals and upper stamens and appear to make up an antepetalous whorl of stamens. Three carpels arise from a low ringwall and grow into a hairy trilocular pistil. In each locule a single pendulous ovule is present. Disclike nectarial tissue is initiated in pits between the stamens and petals. Long trichomes develop on its surface. It is concluded that the androecium is linked with a haplostemonous condition because the stamens of each triplet develop on strictly localized sectors. The distinction between stamens arising on complex primordia and the inception of three independent units is explained by the “principle of variable proportions.” The vasculature also tends to confirm that the outer stamen pairs belong to antesepalous triplets.     

Reevaluation of the perianth and androecium in Caryophyllales: implications for flower evolution

The Caryophyllales have the highest diversity in androecial patterns among flowering plants with stamen numbers ranging from 1 up to 4,000. Thanks to the recent progress in reconstructing the phylogeny of core Caryophyllales, questions of floral evolution, such as the origin and diversification of the androecium, can be readdressed. Caryophyllales are unique among core eudicots in sharing an androecial ring meristem or platform with centrifugal development of stamens and petals. Stamens are basically arranged in two whorls and evolution within the clade depends on the shift of either the antesepalous or the alternisepalous whorls to an upper position on the ring meristem and the reduction of the other. Four main developmental phenomena are responsible for the high diversity in androecial patterns: (1) the sterilisation of the outermost stamens through a division of common primordia; (2) the secondary addition of stamens by a centrifugal initiation of supernumerary stamens superimposed on a lower stamen number; (3) the pairwise displacement of alternisepalous stamens to the middle of the outer sepals and their potential fusion, or as part of a pluristaminate androecium; (4) the inversed sequence, reduction and loss of antesepalous stamens. Shifts in stamen numbers depend on pressures of the calyx and carpels and changes in the number of the latter. These patterns are expressed differently in the three main evolutionary lines of core Caryophyllales and are systematically relevant: (1) A basal grade of Caryophyllales, culminating with Caryophyllaceae, Amaranthaceae, Stegnosperma and Limeum, has the antesepalous stamens initiated in upper position on the ring meristem, and alternisepalous stamens are preferentially reduced. Among the antesepalous whorl there is a progressive loss of stamens following a sequence inversed to sepal initiation. Petaloid staminodes are formed by the radial division of outer stamens. (2) The raphide-clade and Molluginaceae are characterized by alternisepalous stamens in upper position on the ring meristem, with a trend to secondary stamen multiplication, and loss of antesepalous stamens. (3) The Portulacineae share the pattern of the raphide clade, but some taxa show shifts to an upper position on the ring meristem of either antesepalous or alternisepalous stamens, linked with secondary multiplications and reduction of either whorl. Different floral characters are plotted on a recent cladogram of Caryophyllales. The data show a consistent correlation between shifting carpel and stamen numbers independent of perianth evolution. Comparative data suggest that the basic androecium of Caryophyllales consists of two whorls of five stamens, linked with an absence of petals, and the evolution of the androecium is a combination of reductions and secondary multiplications of stamens with a highly predictive systematic value.     

The floral development of Popowia whitei (Annonaceae)

A study of the floral ontogeny of Popowia was carried out to investigate the phyllotactic arrangement of the floral organs and occurring trends in the androecium of Annonaceae. The flower buds arise on a common stalk in the axil of a bract. Three sepals emerge in quick succession and are rapidly overrun in size by two whorls of petals. The androecium is initiated centripetally in successive whorls. A first whorl of three pairs of outer staminodes emerges opposite the outer petals and is followed by nine staminodes. Next a whorl of nine fertile stamens arises in alternation with the second whorl of staminodes. The carpels arise in three alternating whorls of nine. The nature of the perianth parts is morphologically identical. The process of cyclisation of the androecium from a spiral is discussed for Annonaceae and Magnoliidae in general. The inception of the three outer stamen pairs is a widespread reductive step for multistaminate androecia in the process of oligomerization. It is proposed to define the cyclic inception of numerous stamens as whorled polyandry, being an intermediate step between true polyandry and a reduced stamen number in whorls. The absence of a cup-like shape in the carpel development is related to the flattened receptacle.