The Formation of Pollenkitt in Apium nodiflorum (Apiaceae)

Apium nodiflorum produces a considerable amount of pollenkittwithin a secretory tapetum. ER and plastids (elaioplasts) participatein pollenkitt formation. Both organelles deposit precursorswithin vesicles, which finally fuse to form pollenkitt. Apium nodiflorum L., Apiaceaesecretory tapetum, pollenkitt, ER, plastids, elaioplasts     

Photosynthesis, respiration, and chlorophylls in presenescent, regreened, and senescent leaves of forest herb Smyrnium perfoliatum L. (Apiaceae)

Smyrnium perfoliatum L. (Apiaceae), an endangered forest herb with only one main locality in South-West Slovakia (Devínska Kobyla in the Little Carpathian Mountains), is capable to recover chlorophylls at the end of the growing season. This regreening only within bracts was observed during two weeks before achieving the so-called “point of no return” that leads to the last stage of ontogenesis — leaf senescence. The effect not only of endogenous cytokinins on chlorophyll content and carbon dioxide exchange (photosynthesis, mitochondrial respiration, and photorespiration) is discussed but also of other factors such as strong irradiance, high temperature or drought stress on studied parameters was considered.     

Response of CO2 uptake, chlorophyll content, and some productional features of forest herb Smyrnium perfoliatum L. (Apiaceae) to different light conditions

Smyrnium perfoliatum L. (Apiaceae), an endangered summer forest herb grown in the understory of dominant oak-hornbeam stands in Devinska Kobyla, Little Carpathians region in SW Slovakia, is considered to form at least five leaf types of different physiological and anatomical quality. These observation are based upon the estimated differences of photosynthetic carbon dioxide uptake, chlorophyll content, leaf anatomy, and several quantitative parameters of growth analysis. There is a further attempt to establish, to what extent the daily changing environment, especially the excess of light of fast-moving sun-flecks by the photosynthetic apparatus within any leaf type, according to its dominant shade adaptation could be effectively used.     

Pollenkitt is lacking inGnetum gnemon (Gnetaceae)

The anther tapetum of the gymnospermGnetum gnemon produces no lipid osmiophilous droplets as pollenkitt forerunners. Thus—in contrast to entomophilous and anemophilous angiosperms—no pollenkitt is produced at all. From lack of pollenkitt in other gymnosperms, it appears to be restricted to angiosperms. This can be considered as new and additional proof for the hypothesis that the angiosperms are one coherent phylogenetic group, and that the development of pollenkitt in their ancestors was one of the main prerequisites for the adaptive switch to entomophily.     

新疆阿魏的胚胎学研究

采用常规石蜡制片技术,对新疆阿魏不同发育时期的花和果实进行了显微切片观察.结果表明:新疆阿魏小孢子母细胞的减数分裂为同时型,小孢子四分体为四面体型和十字交叉型,成熟花粉粒为3-细胞型.雌蕊2心皮合生成2室,中轴胎座,每子房室内产生上、下2个胚珠原基,其中,下方的原基正常发育,而上方的原基停止发育并最终解体,因此,每室仅产生一枚发育正常的倒生胚珠,单珠被,薄珠心,胚囊发育为蓼型;珠被绒毡层和珠孔塞发生于大孢子四分体时期,并于四核胚囊时分化完全,八核胚囊时珠被绒毡层细胞径向延长;3个成熟的反足细胞具双核.胚乳发育为核型,细胞壁较厚,细胞排列紧密,可保护胚免受机械损伤及防止胚失水.胚乳细胞中含有大量PAS染色呈正反应的物质,一些胚乳细胞异常生长形成细胞体积大、核及核仁均较大的巨形细胞.胚胎发生为茄型,四细胞原胚为直线形,十六细胞原胚的顶部由2排各4个细胞组成.成熟种子具胚乳.     

Pollenkitt formation in Ilex paraguariensis A.St.Hil. (Aquifoliaceae)

 We investigated the cellular and organelle transformations during the formation of the pollenkitt in the secretory tapetum of Ilex paraguariensis. After the dissolution of the callose surrounding the young microspores, the elaioplasts of the tapetum produce many globules of saturated and unsaturated lipids (plastoglobules). Further on, oleosomes with unsaturated lipids, synthesized in the endoplasmic reticulum, accumulate in the tapetal cytoplasm. In contrast to other species, the plastoglobule production seems to precede the oleosome synthesis. The tapetum shows signs of cellular maturation in the late vacuolated microspore stage, when the plastoglobules and oleosomes coalesce and form the pollenkitt mass. In mature stages of the tapetum the pollenkitt is released into the loculus. Finally, it is mainly deposited on the exine, according to the entomophilous character of this species. The mode of pollenkitt formation in Ilex para guariensis and its transfer to the pollen surface is slightly dissimilar to other Angiosperms. Received October 24, 2002; accepted December 2, 2002 Published online: March 20, 2003     

A newFerulago (Apiaceae) species from Turkey

Ferulago antiochia Saya & Miski is newly described: it is known only from the type locality in Hatay province and has affinities toF. trachycarpa Boiss. of sect.Anisotaenia.     

Chromosome numbers of South African Umbelliferae (Apiaceae)

Chromosome numbers are reported for 12 species from nine genera of South African Umbelliferae, of which seven species and one genus (Itasina) are recorded for the first time. A detailed list of all published chromosome counts for southern African species is also presented, together with a review of the literature. The new data obtained are briefly discussed in the context of the taxonomy and relationships of local Umbelliferae. The counts agree with previous reports except that Annesorhiza appears to have 2n = 22, with or without one additional B-chromosome, and not 2n = 24 as reported in the literature. The number for Itasina (2n = 24) is of considerable interest and indicates that a detailed chromosome study of the South African genera Annesorhiza and Chamarea may yield valuable taxonomic information.     

A revision of Centella series Capenses (Apiaceae)

Centella capensis (L.) Domin and related species form a distinct but poorly known group within the genus. The most conspicuous diagnostic feature is the unique inflorescence structure. Each umbel comprises a central umbellule reduced to a single, sessile, functionally female flower and four lateral, functionally male, pedicellate umbellules each reduced to a single flower. The umbel is surrounded by four large, foliaceous bracts. Another unusual character is the habit. Most of the species are annuals or short-lived perennials, while all other species of the genus are perennial shrublets. A taxonomic revision of the four species and three varieties recognized, is presented.     

The influence of hygroscopic movement on seed dispersal in Daucus carota (Apiaceae)

Summary The influence of hygroscopic movement on seed dispersal in Daucus carota was examined. When relative humidity increases, umbels containing mature fruits close; when relative humidity drops, umbels open. Tests of the effectiveness of smalland large-angled umbels on dispersing seeds under various conditions demonstrate that umbels responding greatly to relative humidity (i.e. opening wide) lose seeds more quickly than do umbels responding little, and do not disperse them as far. As relative humidity increases, number of dispersing seeds drops to near zero. Response to changes in relative humidity within an umbel progressively increases from late August when dispersal begins. Umbels that slowly increase their response retain some seeds that may disperse over snow in winter. Individual variation in response to relative humidity is high among plants beginning dispersal at the same time. This variability is probably maintained by the variable consequences of dispersing seeds at different times.     

Taxonomy of the Xanthosia fruticulosa group (Apiaceae)

Xanthosia fruticulosa is shown to be composed of 2 distinct species. The unnamed species is widespread in the semi-arid southern Western Australia, and is described herein.     

伞形科囊瓣芹属的表型分析

选取伞形科(Apiaceae)囊瓣芹属(Pternopetalum Franchet)32个分类群的60个形态学性状,利用DELTA系统的UPGMA算法进行了聚类分析。结果表明属下形成以五匹青(P.vulgare(Dunn)Hand.-Mazz.)和东亚囊瓣(P.tanakae(Franchet&Sav.)Hand.-Mazz.)为代表的两个主要表征群。两个主要表征群的分类结构和各自所包含的类群基本相应于前人研究中本属两个组的属下处理。根据全面相似性分析的结果和部分形态学特征的评估,确认了属下6个种的复合群:即五匹青、囊瓣芹(P.davidii Franchet)、散血芹(P.botrychioides(Dunn)Hand.-Mazz.)、洱源囊瓣芹(P.molle(Franchet)Hand.-Mazz.)、澜沧囊瓣芹(P.de-lavayi(Franchet)Hand.-Mazz.)和东亚囊瓣芹复合群。根据形态学特征在表型树上的分布分析表明:伞形花序的着生位置、花柱的形态、花柱基的形状和萼齿的大小等生殖特征可能是属下早期分化的关键性性状。属下主要变异类型(种的复合群和典型狭域特有种)对不同海拔区域和小生境的依赖,以及不显著的形态学分化表明:对横断山区较高的异质性生境的生态适应是囊瓣芹属类群多样化过程后期的一个重要特征。     

A revision of the genus Annesorhiza (Apiaceae)

The genus Annesorhiza is revised and twelve species are recognized, of which two are newly described: A. altiscapa, A. burttii, A. flbrosa, A. flagellifolia, A. grandiflora, A. lateriflora, A. latifolia, A. macrocarpa, A. nuda, A. schlechteri, A. thunbergii and A. wilmsii. A. marlothii is reduced to synonymy under A. lateriflora , a species hitherto poorly known as Peucedanum lateriflorum. A. thunbergii is only known from the type specimen. A. elata, A. hirsuta and A. villosa are sunk under A. grandiflora. A. fúicaulis has recently been excluded from Annesorhiza on the basis of fruit structure. A key to the species is provided, an update on the nomenclature, typification of names and distribution maps are provided for all the species.     

A new polyisoprenylated phloroglucinol derivative from Hypericum perfoliatum (Clusiaceae)

Hyperfoliatin, a new polyisoprenylated phloroglucinol derivative was isolated from the aerial parts of Hypericum perfoliatum (Clusiaceae) collected in Algeria. The structure of hyperfoliatin was elucidated on the basis of its spectral data, mainly MS and multiple-pulse NMR.     

Immunochemical appraisal of relationships within the tribePeucedaneae (Apiaceae)

An immunochemical investigation of some Old-WorldApiaceae belonging to the tribePeucedaneae has shown close affinity between the generaPeucedanum andAngelica, rather distant position ofFerula and its relatives, and confirmed the separation ofTordylieae as an independent tribe. Some genera, being included in current classifications intoPeucedaneae (Oedibasis, Anethum, Komarovia), are the alien elements in the tribe in the light of serotaxonomical analysis. The independent status of the genusLadyginia has been confirmed.