摘要:

SummaryThe computer program, EXPERT KEY, is an application of expert‐systems technology to the problem of biological identification. The user can use easily‐obtained information about an unknown specimen's colour, location, habitat, etc. to minimise the subsequent search through an ordinary dichotomous key. EXPERT KEY uses the Dempster‐Shafer theory of evidence, a method of reasoning with uncertainty, to combine the heuristic rules. Uncertain inference is also used to allow the user to express Jack of certainty about the statements in the key. The system can reduce considerably the number of difficult key couplets which a user has to assess to make an identification. Unlike previous computer programs in this field, EXPERT KEY is aimed at the non‐specialist who may have problems with technical terms and microscopic examination.

ISSN:0040-0262    

DOI:10.2307/1221121

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryA major obstacle facing many taxonomists interested in analyzing variation at the DNA level is the preservation of their plant material, since plants are often collected far from laboratory facilities. We have studied effect of several commonly used preservation techniques on the quality of DNA isolated from preserved tissue. Chemical treatments (FAA, ethanol, Carnoy's solution, chloroformethanol) all result in DNA degradation; drying tissue, on the other hand, preserves DNA integrity, at least over a several month period. High molecular weight DNA suitable for restriction endonuclease digestion and analysis by DNA hybridization was isolated from dried leaves up to two years old. This suggests that recently‐prepared dried specimens may represent an alternative to fresh tissue in molecular plant systematic studies.

ISSN:0040-0262    

DOI:10.2307/1221122

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryThe history of classification of the generaAcorusandGymnostachys, generally considered to constitute the tribe Acoreae in the family Araceae, is briefly reviewed. Phenetic data appearing to have an important bearing on the placement of these genera are summarized in Table 1, and discussed more fully in the text. These data are interpreted as supporting the removal ofAcorusto its own family, while favoring the retention ofGymnostachysin Araceae.

ISSN:0040-0262    

DOI:10.2307/1221123

出版商:Wiley    

年代:2019

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1221124

出版商:Wiley    

年代:2019

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1221125

出版商:Wiley    

年代:2019

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1221126

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryUsage of‐colusand‐columis to be changed to‐colaunder Art. 32.5 (incorrect Latin terminations), cross‐referenced by Art. 73.1, and as exemplified byRubus amnicola(originally‘amnicolus‘)in Ex. 4 under Art. 23.5. This affects epithets based oncoloorincolo(dwell), whether with substantival sense (dweller in or on) or adjectival (dwelling in or on).

ISSN:0040-0262    

DOI:10.2307/1221127

出版商:Wiley    

年代:2019

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1221128

出版商:Wiley    

年代:2019

数据来源: WILEY

ISSN:0040-0262    

DOI:10.2307/1221129

出版商:Wiley    

年代:2019

数据来源: WILEY

摘要:

SummaryA nomenclatural revision of some Mediterranean algae has been carried out. Fifteen new combinations are proposed.

ISSN:0040-0262    

DOI:10.2307/1221130

出版商:Wiley    

年代:2019

数据来源: WILEY