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ROLF SATTLER LOUISE PERLIN 《Botanical journal of the Linnean Society. Linnean Society of London》1982,84(3):161-182
Three morphological problems were investigated in three species of the Nyctaginaceae: epiphylly, phyllotaxis and placentation. Epiphylly, which occurs in Bougainvillea spectabilis , is the result of ontogenetic displacement resulting from the activity of an intercalary meristem at the base of the floral bract and the floral bud. Floral development of Bougainvillea spectabilis was compared with that of Boerhaavia diffusa and Mirabilis jalapa . Considerable variation occurs with regard to the number and arrangement of stamens. Five stamens are initiated simultaneously, alternate to the petals, in Mirabilis . In Bougainvillea , eight stamens arise sequentially at divergence angles suggestive of a 3/8 spiral. No developmental evidence was found to support the derivation of the eight stamens from a two whorled pentamerous androecium. Boerhaavia normally has only two stamens which most frequently are initiated toward opposite sides of the floral apex, but may also be formed in a 2/5 to 3/8 divergence. In some flowers only one or three stamens are formed. The gynoecium is formed in the same way in all three species: growth occurs in a crescent-shaped zone at the periphery of the floral apex thus producing the gynoecial wall. The single ovule, which is basal in the mature gynoecium, is formed from the gradual upgrowth and transformation of the floral apex and is developmentally terminal. Even the two-layered tunica is maintained as the floral apex is transformed into the ovule primordium. If 'carpel' is defined traditionally as a folded megasporophyll which bears and encloses ovule(s) then carpels are not present in the gynoecia of the three species studied. If 'carpel' is re-defined as an appendage which encloses ovule(s), then the gynoecia of the Nyctaginaceae are carpellate. However, the ovules remain cauline regardless of which definition is adopted. 相似文献
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Multivariate analysis, specifically principal components analysis,shows that in flowering plants structures occur that arc intermediatebetween the typical representatives of a root, a caulome (stemand stem homologues), a phyllome (leaf and leaf homologues),a shoot and a trichome. Since these intermediates span the wholerange between the typical forms, a morphological continuum isdocumented. Implications and consequences of these findingsare discussed (e.g. homology, homeosis). The telome theory andHagemann's theory of the evolution of plant form are interpretedas referring to changes in the patterning of the morphologicalcontinuum. Plant morphology, principal components analysis, morphological continoum, angiosperms, flower, shoot, stem, leaf, enation, trichome, root, telome, thallus, morphological categories, homology, partial homology, homeosis 相似文献
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Abstract. Aumakua omaomao gen.n., sp.n. (Noctuidae: Cuculliinae) from the Hawaiian Islands is described; the adults, wing venation and genitalia of both sexes are illustrated. The systematic position of Aumakua gen.n. is discussed, its status as a Hawaiian endemism is considered and the habitats of A.omaomao sp.n. are described. 相似文献
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Abstract Normanbya normanbyi (W. Hill) L. H. Bailey (Arecaceae) is a monoecious, arborescent palm with a very small distribution area within the Daintree rainforest in north‐eastern Australia. Our 2‐year study was focused on the reproductive phenology at the individual and population level. At the population level flowering peaked in the dry season, whereas fruiting was confined to the wet season. Each palm can bear up to three inflorescences/infructescences at the same time. Flowering of each inflorescence is separated from each other by a couple of weeks. A single inflorescence consists of about 1900 staminate and 800 pistillate flowers. The flowering of N. normanbyi is protandrous with a staminate phase lasting 40 days and a pistillate phase of approximately 2 weeks. Between both phases is a non‐flowering phase of about 9 days. Fruit ripening takes 21 weeks, with an average of about 280 ripe fruit per tree. Comparison of three study plots revealed a moderate synchrony of flowering and fruiting initiation in this species of palm. The male phase of flowering shows a higher degree of synchrony than the female phase at the population level. Seasonal regularity of flowering and fruiting peaks appears to be predictable. The general flowering and fruiting phenology of N. normanbyi follows a subannual pattern with a strong tendency towards a continual pattern. 相似文献
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从嗜碱放线菌YIM 80149的发酵液中分离得到4个抗肿瘤活性成分.根据波谱数据,鉴定为4',7-dihydroxyisoflavone(1)、4',5,7-trihydroxyflavone(2)、3-(4-hydroxy-3-methoxyphenyl)-2(E)-propenoic acid(3)、2-methoxy-1,4-naphthoquinone(4). 相似文献
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CLAIRE COONEY-SOVETTS ROLF SATTLER 《Botanical journal of the Linnean Society. Linnean Society of London》1987,94(3):327-371
Phylloclades are traditionally defined as flattened, determinate, leaf-like stems primarily on the basis of their axillary position. However, because the literature is replete with controversy over the morphological interpretation of these organs, a study of phylloclade development in comparison with leaf and stem development was undertaken in four closely related species of the Asparagaceae: Ruscus aculeatus, Danae racemosa, Semele androgyna and Asparagus densiflorus. Results reveal a continuum in phylloclade development from very leaf-like forms, such as those of Danae, via the more intermediate types of Ruscus, to the gradually more shootlike forms of Semele and Asparagus. This continuum results from a differential expression of stem (or shoot) and leaf characteristics in an axillary position. When stem (or shoot) and leaf features are combined, as in the fertile phylloclade of Ruscus, an intermediate organ is formed. Phylloclades are a form of evolutionary novelty that exemplifies the phenomenon of homoeosis, which is the transference of features from one organ to another. Developmentally, this means that leaf features are expressed by the axillary meristem. 相似文献
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T. A. DICKINSON R. SATTLER 《Botanical journal of the Linnean Society. Linnean Society of London》1974,69(1):1-13
The inflorescence primordium of Phyllonoma integerrima (Turcz.) Loes. is initiated on the adaxial side of the leaf primordium. At about the same time, a vegetative bud is formed at the base of the same leaf primordium. The vascular anatomy is the same in the fertile and sterile leaves, except that in the fertile leaf an inflorescence trace departs from the midvein of the leaf at the point where the inflorescence is inserted. Neither the inception nor the procambial supply of the inflorescence provide evidence of “congenital fusion”of inflorescence and leaf. It is also argued that the idea of an “adventitious”origin of the inflorescence is not useful in this case. Consequences for our conception of shoot construction are pointed out. It is argued that positional changes in the initiation of organs is an evolutionary process that may have remarkable effects on plant construction. 相似文献
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应用各种层析手段,从红树植物内生真菌的发酵液中分离纯化了一个新的木质素类化合物,结合多种波谱方法确定其结构为4,4′-二(1-丙烯酸甲酯)-3′-甲氧基-二苯醚(1)。 相似文献