摘要:

Caffeic acid is plotted in the Dahlgren diagram and its distribution is compared to that of proanthocyanidins, the condensed tannins. The two chemicals derived from the same basic substance by a shift in the later steps in the pathway. Caffeic acid derivatives may be seen as more advanced constituents than proanthocyanidins.Caffeic acid may function as a biosynthetical sink for surplus cinnamic acid in a system where the end‐product, proanthocyanidins, has lost importance, and where lignin is not formed. Consequently, this may apply to all groups where a shift from woody to herbaceous habit has occurred, i.e. Asteridae, Araliiflorae and Ranuncu‐liflorae. This is used as an argument in the presentation of a theory that evolution in dicotyledons was dichotomous. One main Magnoliiflorean‐Caryophylliflorean group terminates in Ranunculiflorae and Caryophylliflorae with caffeic acid and ferulic acid, respectively. The other group, comprising most other dicotyledons, terminates in the Asteridae, also with caffeic acid.There is much evidence pointing towards a similar protective effect of caffeic acid as has long been known for the condensed tannins. The advantages of caffeic acid as compared to condensed tannins is the shorter biosynthetic pathway, the less carbon bound in the molecule, and the possibility of re‐entering the substance into the primary met

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01648.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01649.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The genusRipogonumJ. R. et G. Forst. is usually included in either the Smilacaceae or Liliaceae, but it has been accorded family rank. A numerical taxonomic study of the phenetic relationships ofRipogonumand all genera of the Smilacaceae, Dio‐Scoreaceae, Petermanniaceae, Philesiaceae and Luzuriagaceae has been undertaken in terms of 56 characters. The results support the view thatRipogonumis only distantly related to either Smilacaceae or Dioscoreaceae and instead has affinities with Luzuriagaceae. None‐the‐lessRipogonummerits family status and so Ripogona‐ceae are formally va

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01650.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Preparatory to the publication of the Flora of Ethiopia, the following new species and combinations are made: Loranthaceae:Plicosepalus robustusWiens&Polh.,P. ogadenensisM. Gilbert,P. acaciae(Zucc.) Wiens&Polh.,P. meridianus(Danser) Wiens&Polh.;Oncocalyx angularisM. Gilbert,O. fischeri(Engl.) M. Gilbert,O. glabratus(Engl.) M. Gilbert,O. ugogensis(Engl.) Wiens&Polh.,0. schimperi(Hochst. ex A. Rich.) M. Gilbert,O. ghikae(Volkens&Schweinfurth) M. Gilbert,O. kelleri(Engl.) M. Gilbert;Erianthemum aethiopicumBalle ex Wiens&Polh.;Englerina woodfordioides(Schweinfurth) Balle ex M. Gilbert;Phragmanthera ahhallensis(Engl.) M. Gilbert,P. erythraea(Sprague) M. Gilbert,P. macrosolen(Steud. ex A. Rich.) M. Gilbert,P. regularis(Steud. ex Sprague) M. Gilbert,P. sarertaensis(Hutch.&Bruce) M. Gilbert,P. usuiensis(Oliver) M. Gilbert. Viscaceae:Viscum triflorumDC. ssp.nervosum(A. Rich.) M. Gilbert.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01651.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The six species up till now described in the genusSphinctacanthusBenth. are reconsidered. Five of them, originating from Burma through Thailand to the Malay Peninsula and Sumatra are excluded and their true identity given. The type species,Sphinctacanthus grifithii(T. Anderson) Benth. is provided with an emended description. The generic affinity within the family is discussed with emphasis on pollen morphology and cystolith morphology.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01652.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Three South African species of the African genusEriospermum Jacq., which makes up Eriospermaceae Endl., have been studied in connection with the project “Families of Vascular Plants”, partly to establish the phylogenetic relationships of the family. The embryology is unusual in several features reflecting the advanced character of the genus in this respect. The following features are the most important: the tapetum is secretory; microsporogenesis is successive; the ovules are anatropous and crassinu‐cellate; the primary archesporial cell cuts off a parietal cell; the embryo sac formation is of the Polygonum type; endosperm formation is nuclear, but the endosperm is soon consumed, nucellus cells bordering on the sides of the chalazal half of the embryo sac divide to form a perispermal sheath around the embryo; embryo formation follows the Nicotiana variation of the Solanad type; the embryo of the mature seed is large and cylindrical‐obconical, reaches above the perisperm. The seed coat is formed by both the outer and the inner integuments, both 2‐layered; the epidermal cells of the test a grow out into long trichomes. The embryology and seed shape ofEriospermumis compared to those inCyanastrum, Walleria, and genera of Tecophilaeaceae and some other families as far as details in these

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01653.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Tapetal cells ofPinus sylvesirisL. underwent one hypersecretory cycle during early pachytene and entered a second cycle by the time of mid pachytene in microspore mother cells. Initially in each cycle tapetal cells became papillaform then dome‐shaped and thereafter, in conjunction with radial narrowing of the cells, dilation of the ER system was intensive throughout the cytoplasm. Recovery from hyperactivity culminated with the presence of plasmodesma‐like connections between tapetal cells and a period of mitosis in tapetal cells. The differentiation of tapetal cells occurred asynchronously within a microsporangium and their dedifferentiation began nonuni‐formly, becoming synchronous coincidental with the presence of “plasmodesmata”. Microsporangia increased in size and tapetal cells were laterally wide before “plasmodesmata” receded and tapetal cells again differentiated a

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01654.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Cycles of hyperactivity were observed in tapetal and microspore mother cells ofPinus sylvestrisL. during the pachytene stage of meiosis in microspore mother cells. Hyperactive periods were characterized by dilated rough ER, hypersecretory dictyosomes, autophagic vesicles having one to two sequestration envelopes, and maze‐like whor‐les of the endomembrane system. The extent and sequence of differentiation differed between the two cell types. During distinct phases of development there was either fi‐brillar flocculent or lipoidal material or both within dilations and at cell surfaces. Tapetal cell transfer of material involved endocytotic and exocytotic vesicles and channels opening directly to the cell surface. Dilations of the nuclear envelope of microspore mother cells in late pachytene intruded into the nucleus and, in conjunction with dilated ER, dominated cell profiles. Cellular morphogenesis in a microspo‐rangium was seldom synchronous except for intervals of dedifferentiation when plas‐modesma‐like connections were formed between tapetal cells. Cycles of differentiation and dedifferentiation were correlated each spring season for five years with the progressive change of pachytene chromosomes, suggesting control by a genetic program rather than annual variations in the

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01655.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Idealized distributions of phytosociological syntaxa are arranged along topographical gradients on siliceous and carbonaceous substrates in the northern arctic tundra zone of Svalbard. Two alliances (Luzulion arcuatae all. prov. and Papaverion dahliani Hoffm. 68 all. prov. em.) and three associations (Gymnomitrio corallioidis ‐ Luzule‐tum arcuatae ass. prov., Cetrario nivalis ‐ Luzuletum arcuatae ass. prov. and Raco‐mitrio lanuginosi — Luzuletum arcuatae ass. prov.) are proposed. Luzulion arcticae (Nordh. 36) Gjaerev. 56 and Polytrichion norvegici Gjierev. 49 described from Scandinavia are supposed to be important syntaxa on Svalbard. A subdivision of the Arctic into four zones, arctic polar desert zone, and northern, middle, and southern arctic tundra zones, is proposed. These zones and the transitional hemiarctic zone are defined and mapped in Europe and adjacent areas according to phytosociological criteria. They are also compared with alpine belts of Fennoscandia. The following zonal syntaxa are proposed for Europe and Greenland: Phyllodoco — Vaccinion in the hemiarctic zone, Loiseleurio — Diapension in the southern arctic tundra zone, Kobre‐sio — Dryadion (Tetragono — Dryadetum) in the middle arctic tundra zone, Luzulion arcticae in the northern arctic tundra zone, and Papaverion dahliani in the arcti

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01656.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

The Mallomonadaceae (Chrysophyceae) of Malaysia and Australia are described by scanning and transmission electron microscopy. Thirty taxa are reported from Malaysia, twenty eight for the first time. Eighteen taxa are reported from Australia, twelve for the first time. Twelve taxa are reported for the first time from the tropics. Four new taxa,Mallomonas ocellatasp. nov.,M. tropicasp. nov.,M. favosaf.geminaf. nov. andChrysosphaerella astreasp. nov. are described and the diagnosis ofMallomonas adamasHarris et Bradley is emended.

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1985.tb01657.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY