摘要:

The suggestion thatTrigonobalanus excelsareached Colombia by migration from south‐east Asia via the Bering land‐bridge is criticized. The distribution ofTrigonobalanuscan be more simply explained by the disruption and drift of the former Pacific continent and the peninsula of West Gondwanaland. All but the New Guinea species ofNothofagusremain on the drifted fragments of the Gondwana peninsula, the original home of the family. Drift accounts for the present disjunct distribution of relatedNothofagusspecies in the Southern hemisphere, but topoclines in characters of the fructifications and of the leaves linking New Zealand, New Caledonia and New Guinea indicate the overland migration route into the Pacific continent. Diversification of the family occurred in Pacifica before that continent was disrupted in the late Jurassic. With the formation of Eurasia, a topocline in leaf characters developed inFagusalong the migration route from China to Western Europe. Absence of topoclines involving the Bering land‐bridge indicate that this bridge played no significant part in the dispersal of the Fagaceae. Shedding of the fruits ofGlossopterisbefore the development of an embryo draws attention to the primitive character of delay in fertilization found inNotho

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1982.tb00586.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

A new genus of juglandaceous winged fruit, is described from the Reading Beds (Upper Palaeocene) of southern England. It comprises one of the earlier macrofossil records of the Juglandaceae, and is the earliest from the European Tertiary. The fruit represents an extinct genus related to the extant tribe Engelhardieae, but excluded from it by its simple unlobed bract. Cladistic analysis showsCasholdiato display generalized engelhardioid fruit morphology. It lacks the tri‐lobed bract diagnostic of the Engelhardieae, and predates the first occurrence of such bracts in the fossil record.Casholdiaadds to the mounting evidence indicating an early Palaeogene radiation of the Juglandacea

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1982.tb00587.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Anatomical and floral data were collected from 202 species in 34 genera or species complexes of the Pleurothallidinae (Orchidaceae). A data matrix was compiled from scorings of 45 continuous or discrete variables, including 35 vegetative characters and 10 floral characters. Different cluster and factor analyses were performed with this data matrix in order to identify phenetically similar taxa and at the same time reveal differences in results owing to different statistical procedures. Regardless of the clustering method applied, several genera or complexes are measurably distinct from each other and all other Pleurothallidinae, notablyDracula, Dresslerella,and thePleurothallis alexandraeandPleurothallis pedunculariscomplexes. After further, confirmatory studies, it may become appropriate to erect new genera for thePleurothallis alexandraeandPleurothallis pedunculariscomplexes. Phenetic relationships identified suggest at least seven major phylogenetic lines in the subtribe, which represent adaptations to both the epiphytic regime and dipteran pollination.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1982.tb00588.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Pandanus tectoriusParkins, is a widespread and variable species with many forms, often local, some of which have been considered as distinct species. Fourteen binomials are here considered as synonyms ofP. tectorius,but several of them warrant retention at varietal rank. Comments on the variability and its relation to a species concept in the genusPandanusare included.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1982.tb00589.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Polyembryony and twin seedlings are noted inBorassus flabelliferL. Both seedlings arising from a seed have an independent hatistorium, cotyledonary sheath, scale leaf and root system. There are instances where twin seedlings are identical in structure and activity; independent plants develop in the same way as normal seedlings. The haustoria of these seedlings are equal in size and activity. Cases are also recorded with disparity in size and activity between twin seedlings. While the haustorium of the bigger seedling is normal, that of the smaller seedling is reduced.

ISSN:0024-4074    

DOI:10.1111/j.1095-8339.1982.tb00590.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY