Abstract
LONDON. Linnean Society, December 14.—Dr. A. Smith Woodward, president, in the chair.—W. O. Howarth: On the occurrence of Festuca rubra in Britain. Representatives of three subspecies, three varieties, six subvarieties, and the forms of Hackel's F. rubra, occur in Britain.—H. W. Pugsley: British species of Calamintha and a species new to this country. The three recognised British species are said to be Calamintha ascendens, Jord., C. Nepeta, Savi, and C. sylvatica, Bromfield. The new form, first found near Swanage, in Dorset, in 1900, and again in 1912, was identified with C. bætica, Boiss. and Reut., although showing differences in minor features, which were attributed to climatic influence.—Lily Batten: The genus Polysiphonia; a critical revision of the British species, based upon anatomy. British species of Polysiphonia show great diversity of habitat. Four main types are distinguishable: (1) Ecorticate plant attached when young by rhizoids developed by longitudinal proliferation of basal siphons. Later, siphons of procumbent branches develop rhizoids, which may have discs at their distal ends, or may ramify among filamentous algae, or may be swollen to form haustoria. (2) Species having a number of siphons or the beginning of cortication at the base, show elementary aggregation of the rhizoids to form one large disc. (3) Stunted procumbent branches develop at the base of the plant, which produce attachment rhizoids. (4) Corticate species having an upright habit develop a large disc-like expansion by the longitudinal proliferation of basal siphons and corticating cells. The genus is divided into thirteen ecorticate and eleven corticate species, and P. spiralis is described for the first time.
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Societies and Academies. Nature 111, 67–68 (1923). https://doi.org/10.1038/111067a0
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DOI: https://doi.org/10.1038/111067a0