Genus Primula Research Articles

The Genus Primula: Section Candelabra, Balf. Fil

The Genus Primula: Section Candelabra, Balf. Fil

On the Eelworm Disease of Primulas caused by Anguillulina dipsaci, Kühn

In Britain, the year 1937 is likely to be memorable in the history of cultivation of many species and varieties of plants belonging to the genus Primula, as witnessing, for the first time, attacks of great severity by the nematode, Anguillulina dipsaci in a number of plantations of Primulas, reducing the vitality of the plants wherever it occurred, and in many instances causing complete destruction of certain species. The plants classed as members of the Candelabra Section, which includes some of the finest and most extensively grown species and varieties in the whole genus, proved particularly susceptible but, while members of many of the other Sections of Primulas did not escape attack, the injury inflicted was not usually of such high order of severity.

Anatomical Features in the Roots of the Genus Primula

Anatomical Features in the Roots of the Genus Primula

Taxonomy and Cytology

THE Hooker lecture of the Linnean Society delivered on February 16 last, by Sir William Wright Smith (Proc. Linn. Soc, Part II, 1932-33), dealt with this subject, with specific reference to the genus Primula. Sir William examined the taxonomic value of the criteria submitted by the cytologist. This genus is particularly suitable for such a comparison as morphologically it is divisible into some thirty reasonably definite sections. Cytologically the same is true and, on the whole, the analysis from this point of view agrees with the morphology very well. Sir Williams general conclusion appears to be that chromosomic divergence would certainly indicate usually that a line can be drawn between two groups, but it would not follow that even a marked difference would justify generic separation. Such separation would require to be based on the morphological evidence at the final arbitrament.

Presidential Address.—The European Species of the Genus Primula

Presidential Address.—The European Species of the Genus Primula