摘要:

Odland, A. 1995. Frond development and phenology ofThelypteris limbosperma, Athyrium distentifolium, andMatteuccia struthiopterisin Western Norway. — Nord. J. Bot. 15: 225–236. Copenhagen. ISSN 0107–055X.The pattern of growth and phenology ofThelypteris limbosperma, Athyrium distentifolium, andMatteuccia struthiopterisfronds has been investigated, with particular emphasis on height increments of the sporophytes and the development of fertile fronds. In order to study both interspecific and intraspecific differences, fern stands along altitudinal gradients have been monitored. To investigate the initiation of fertility, fronds representing different developmental stages have been sampled. Climatic data have been collected with a data‐logger during the study periods.The ferns show significant differences in growth pattern and phenology.Matteuccia struthiopterishas a growth curve that is best described as monomolecular, characterised by high growth rates during the early developmental stage, while the development ofThelypteris limbospermaandAthyrium distentifoliumfollow a logistic growth curve. The species need different periods of time to develop their fronds. The main frond elongation does not start before soil temperature has reached 7 C. After that, the growth is mainly controlled by air temperature. Within the interval when mean maximum temperatures are 8–20 C, all three ferns showed increased growth rates with increasing air temperatures, but the increase was greatest inM. struthiopteris. At higher temperatures, the growth rate ofM. struthiopterisandT. limbospermadecreased.Athyrium distentifoliumis characterised by producing sori at an early developmental stage. FertileMatteuccia strurhiopterisfronds are developed at a much later developmental stage.Thelypteris limbospermaneeds a longer period of time to produce mature fronds than the other species. The investigation indicates that plant growth and development are determined by both internal and external factors. It is concluded that growth rate, phenology, and the ability of ferns to produce mature fronds reveal close similarities with their response to environmental variables, and hence with their broad‐scale geographical distribution

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00147.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Kraft, T., Nybom, H.&Werlemark, G. 199.5.Rubus vestervicensis(Rosaceae) — its hybrid origin revealed by DNA fingerprinting. — Nord. 3. Bot. 1.5: 237–242. Copenhagen. ISSN 0107‐055X.The large number of species inRubussubgenusRubusare thought to have arisen, at least in part, through hybridiation between facultatively apomictic species.R. vestervicensisis known only from a small island off the Swedish east coast. It has been suggested that it is a hybrid betweenR. grabowskiiandR. pedemontanus. We have compared these species with DNA fingerprinting and our results support the hybridization hypothesis. All bands found in the fingerprint ofR. grabowskiiand about half of the bands found inR. pedemontanuswere present inR. vestervicensis, suggesting that the latter species was derived from fertilization of an unreducedR. grabowskiiegg cell withR. pedemontanu

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00148.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Norderhaug, A. 1995. Mating systems of three meadow plant species — Nord. J. Bot. 15: 243–250. Copenhagen. ISSN 0107–055X.The area of species‐rich hay meadows in Norway has been drastically reduced during the 20th century. This continuing process results in fragmentation and isolation of remaining habitats. Small and isolated populations may have reduced gene flow. This is a crucial factor for the structure and cohesiveness of populations. Gene flow in plant species is regulated by pollen and seed dispersal, and pollen dispersal is controlled by the species' mating system. As part of a research project on habitat fragmentation three meadow species (Dactylorhiza sambucina, Hypochoeris maculata, Polygala vulgaris) with different life strategies were therefore selected for studies of their mating systems. A hand pollination experiment showed that bothDactylorhiza sambucinaandPolygala vulgariswere self‐compatible. Seed set inH. maculatawas low and the species may be considered as pseudo‐self‐compatible or self‐incompatible. Using Bawa's (1974) criteria, however, alsoHypochoeris maculatashould be considered as self‐compatible. All three species enhanced outbreeding butP vulgurisalso proved to be a good self

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00149.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Alatalo, J. M.&Molau, U. 1995. Effect of altitude on the sex ratio in populations ofSilene acaulis. —Nord. J. Bot. 15: 251–256. Copenhagen. ISSN 0107–055X.Predicted increase of female frequencies in gynodioeciousSilene acauliswas tested along an altitude gradient in northern Sweden. Average female frequencies for the four sites increased with altitude from 42% to 59% within a short geographical distance. This follows the outcrossing hypothesis, that female frequencies should be positively correlated with selfing rates of hermaphrodites in populations. More adverse environmental conditions should favour gynodioecy in areas where reproduction to a greater part relies on vegetative reproduction or selfing. Further, a significant difference in corolla width was found between females and the larger hermaphrodites, but not between sites. Cushion size and the number of flowers per cushion decreased with att

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00150.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Bernhardt, K.‐G. 1995. Seed burial by soil burrowing beetles. — Nord J. Bot. 15: 257–260. Copenhagen. ISSN 0107–055X.This investigation shows the role of soil digging beetles (Carabidae, Heteroceridae) in burial of myxospermous seeds. Field experiments with containers filled with sterilized sand, seeds of different plant species and soil digging beetles, are used. After six months in plots with digging insects seeds were found in deeper soil depths (up to 10 cm soil depth) than seeds in control plots. The study was done with beetles belonging to newly created sandy land. The study shows that beetles can be important for seed dispersal and seed burial and that seeds deep in the soil do not need to

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00151.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Thulin, M.&Hjertson, M. 1995.Echidnopsis globosasp. nov. (Asclepiadaceae‐Stapelieae) from Yemen. — Nord. J. Bot. 15: 261–262. Copenhagen. ISSN 0107–055X.The new speciesEchidnopsis globosafrom rocky hillsides on limestone in the Hadramaut Region in Yemen is described and illustrated. It belongs to a group of species includingE. squamulatafrom Yemen andE. ericiflorafrom Kenya, but is unique in the genus by its almost perfectly globose

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00152.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Schubert, M. T. R.&Van Wyk, B.‐E. 1995. A taxonomic study of theCentella rupestrisgroup. — Nord. J. Bot. 15: 263–268. Copenhagen. ISBN 0107‐055X.Centella rupestris, C. restioidesand a new species,C. thesioides, are grouped together on the basis of a woody habit, acicular or linear leaves and large bracts which cover, or partially cover the flower and fruit. The taxonomy, geographical distribution and species delimitation of this complex have been clarified through herbarium studies and in situ studies of the habit, leaves, inflorescences, bracts an

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00153.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Rova, J. H. E.&Andersson, L. 1995. A reevaluation of the tribes Hippotideae and Tammsieae (Ruhiaceae). — Nord. J. Bot. 15: 269–284. Copenhagen. ISSN 0107–055X.The generaHippotis, Pentagonia, Sommera, andTammsia, the hippotides, have recently been removed from their traditional position in the tribe Isertieae and proposed to form two separate tribes, Hippotideae (the three former genera) and Tammsieae (the latter one). In the most recent overview of the classification of the Ruhiaceae, the position of these tribes was considered uncertain. The morphology and micromorpho‐logy of representatives of all genera were reexamined and data were analysed cladisti‐cally. It is concluded that the original distinction between the Hippotideae and Tammsieae was based on faulty observations, the hippotides being uniform in ovary morphology. The cladistic analysis suggests that the hippotides form a monophyletic group, within whichTammsiais nested. It is therefore proposed that Tammsieae should he reduced to a synonym of Hippotideae. There are no indications that the hippotides should he reunited with the Isertieae. The genusWiasemsbaKlotzsch is shown to he synonymous withTammsia, and it is argued that the genusStriolariaDucke is synonymous withP

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00154.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Persson, C. 1995. Exotesta morphology of the Gardenieae‐Gardeniinae (Rubiaceae). ‐Nord. J. Bot. 15: 285–300. CGpenhagen. ISSN 0107–055X.Exotesta morphology of 68 species in 59 genera of the Gardeniinae were examined with the aid of scanning and light microscopy. The shape of the exotesta cells in surface is either isodiametrical or elongate and both shapes occur among New World and Old World genera. All genera, except forMonosalpinx, PosoqueriaandMacrosphyra, are provided with secondary thickenings in the cell walls of the exotesta. The majority of the genera has a thickened radial wall. In the Asian generaCatunaregam, Deccania, Tamilnadiaand the mainly Pacific genera,AtractocarpusandTrukiathickenings of the radial wall are very low or absent. In nearly half the genera the inner tangential wall is provided with thickenings, usually in the shape of a continuous plate. However, in four African genera,Atractogyne, Didymosalpinx, MitriostigmaandSherbournia, the wall is provided with elongate anastomosing ribs.Atractocarpusdiffers markedly from the rest of the Gardeniinae by its ring‐like thickenings in the inner tangential wall. Thickenings, in the shape of a continuous plate, in the outer tangential wall is restricted to three neotropical genera,Alibertia, AmaiouaandBorojoa. Presence of distinct knobs is common in palaeotropical genera, whereas in neotropical genera this feature is only present inCasasiaandKotchubaea. It is concluded that data on exotesta morphology alone does not support any of the previously proposed informal groups, but may still be an important character to deduce phylogenetic relationships, primarily on a level just above

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00155.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

Sirirugsa, P.&Larsen K. 1995. The genusHedychium(Zingiberaceae) in Thailand. ‐Nord. J. Bot. 15: 301–304. Copenhagen. ISSN 0107–05513.Three new species ofHedychiumfrom Thailand are described and illustrated,H. samuiense, H. tomentosum, andH. biflorum. A key to the species occurring in Thailand is pro

ISSN:0107-055X    

DOI:10.1111/j.1756-1051.1995.tb00156.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY