No abstract

Although Cupressus sempervirens has been spread over southern Europe since antiquity, cypress pollen allergy has not been reported until 1945 (1). In France, the very first case reports were published in 1962 (2). Since then, the prevalence of cypress pollinosis seems to demonstrate an upward trend, concomitantly with the increased use of cypress trees as ornamental plants, as wind breaks and as hedges. Hyposensitization, using improved pollen extracts, is increasingly prescribed. Besides, prevention measures begin to be implemented. Such measures include avoidance of planting new cypress trees, especially near human populations’ centres, trimming of cypress hedges before the pollination season and agronomical research for hypoallergenic trees. Altogether, such new developments in cypress allergy deserve an update review.

No abstract

The contribution of each of the salt‐transporting processes to the NaCl balance of the leaves of the salt‐recreting mangrove Avicennia marina (Forssk.) Vierh. was quantitatively investigated. Transpiration rates, xylem sap concentration, leaf salt content, recretion rates and rates of salt retranslocation out of the leaves were continuously monitored during three day periods and the salt fluxes in and out of the leaves were calculated. The results indicated that salt filtration by the roots is by far the most important salt‐rejecting mechanism, preventing some 80% of the salt which is carried towards the root surface by the transpiration stream, from entering the shoot. Out of the remaining quantity of salts which enter the root xylem and reach the leaves, only 40% is removed by the salt‐recreting glands.

SUMMARY Salt glands were observed in twenty‐five species belonging to the Chlorideae, Sporoboleae and Aeluropodeae tribes of the Gramineae. Most of those species are presently glycophytes, and the possession of salt glands suggests that they had a common halophytic ancestor.