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The article presents information on a paper that gives detailed account of the vegetation of the Aden peninsula, in south-western Arabia, which has an area of about 1.5 square miles and consists chiefly of a mass of volcanic rocks, reaching its greatest elevation in ranges. The author lists several plant species, which include Monocotyledons, Dicotyledons, Leguminosae, Capparidaceae, Euphorbiaceae, Boraginaceae and Chenopodiaceae, Compositae, and Scrophulariaceae. It is inferred that the paucity of species in the flora is not the result of situation or isolation, but simply that of the meteorological factors combined with unfavourable edapbic conditions.

The kinetics of the inhibition of photophosphorylation in chloroplasts from spinach (Spinacia oleracea) was investigated with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) in small concentration intervals, starting at 10-7 M. Plots of the reciprocal of photophosphorylation against concentration of DCMU gave essentially the same straight line with 2 mM nicotinamide adenine dinucleotide phosphate (NADP) together with saturating amounts of ferredoxin or with 4 mM K3Fe(CN)6 as the final acceptors for electrons. Practically complete inhibition was obtained at 3 × 10-6 M DCMU. With 0.1 mM flavin mononucleotide (FMN) and ferredoxin, the inhibition between 10-7 M and 10-6 MDCMU was a little slower than in the other two cases. At 10-6 M DCMU a break occurred to a new straight line in the plots, indicating that another reaction was inhibited. Total photophosphorylation without DCMU was about 77 μmol ATP per mg chlorophyll and hour. At the breaking point 20 % remained, and inhibition was not complete even at 8 × 10-6 MDCMU. The inhibitor constant for the high-DCMU reaction was in the order of 2 × 10-5 M; for the low-DCMU reaction some complication made the "constant" appear negative. With phenazine methosulfate (PMS) added, DCMU was without effect on photophosphorylation. - As earlier shown by us, titration curves for intact cells of the microalga Scenedesmus show the break at 1010-6 M DCMU; and above 6 × 10-6 M photophosphorylation in the algae is not further decreased by DCMU. The data are compared and their possible significance is discussed. [ABSTRACT FROM AUTHOR]

The article offers information on the plant Chenopodium album L. The plant is described as a branched annual, erect, mealy white, especially the flowers and undersides of the leaves, and the mealiness is most abundant when the plant is young. The plant's lower leaves petiolate, ovate-rhombic, wedge-shaped at the base and sinuately toothed. The stems of the plant, according to the article, are often red due to anthocyanin pigment. It states that the inflorescence of numerous small inconspicuous flowers are arranged in a spicate, indeterminate or cymose pattern.

The article presents a study on the effects of manurial and cultural treatments on soil properties and on vegetable crops, including Stellaria media, Poa annua and Chenopodium album. It states that in 1952, the Chemistry section at the National Vegetable Research Station planned three long-term field experiments for the study of the impacts of manurial and cultural treatments on soil properties and vegetable crops. These experiments are conducted in Soakwaters, which is a field of 36 acres in Warwick, England. Results showed that after the first year of vegetable cropping, it was found that the population of vegetable crops had been reduced to 38% of the original level. By the end of the second year of cropping, however, the population had fallen by 19% of that originally present.

Seeds of Salicornia bigelovii were germinated at 4.4°C, 15.5°C, and 26.6°C in saline solution containing from 0% to 8.08% sea salt. At 4.4°C, germination was delayed until the 26th day, but the final germination per cent was high in all salinities. At 15.5°C, germination was delayed until the 19th day, and the germination per cent was higher in the higher salinities. At 26.6°C, the germination began within one day and the germination per cent was higher at the lower salinities. With the exception of 26.6°C data, the maximum germination occurred at a sea salt concentration at 4.04 % which is very close to the salinity of the sea. [ABSTRACT FROM AUTHOR]