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Forms of seed dispersal in Cactaceae
- R. Bregman
- Environmental Science, Biology
- 1 September 1988
A survey is given of the possible types of seed dispersal in Cactaceae and a clear difference in the floating capacity between seeds with a small hilum cup and others with a large one is demonstrated.
Periodicity in growth, productivity, nutrient content and decomposition ofSphagnum recurvum var.mucronatum in a fen woodland
Condition in the understory of aBetula-carr appeared to be favourable for the growth ofSphagnum recurvum, and its potency in directing succession in peatland forests is indicated.
Other tetraploid species and conspecific diploids as sources of genetic variation for an autotetraploid.
- M. Stift, R. Bregman, J. Oostermeijer, P. V. van Tienderen
- Biology, MedicineAmerican journal of botany
- 1 November 2010
The role of gene exchange and introgression in autotetraploid Rorippa amphibia is explored and it is found that gene flow through unreduced gametes from diploids could be an important source of genetic variation for tetraploids.
Seed germination in Cactaceae
Within the subfamily Cactoideae operculum formation was found to occur in all tribes and in all investigated subtribes.
Taxonomy, phylogeny and biogeography of the tridentigera group of the genus Chremistica Stål, 1870 (Homoptera, Cicadidae)
- R. Bregman
The tridentigera group is one of four groups within the genus Chremistica Stal that is distributed in Southern India, Sri Lanka, Thailand, Laos, Malaya, Sumatra, Kalimantan and the Philippines.
Holocene raised bog deposits in the Netherlands as geochemical archives of prehistoric aerosols
SUMMARY High resolution records of lead and some other elements in Holocene raised bog deposits from the eastern Netherlands were compared with corresponding pollen records for the period 1000 bc…
SUBCUTICULAR SECRETION BY CACTUS SEEDS IMPROVES GERMINATION BY MEANS OF RAPID UPTAKE AND DISTRIBUTION OF WATER
A formerly unknown mechanism in seeds is reported which improves germination under relatively dry conditions and ensures germination with the minimum amount of available water, which may be advantageous in (semi-)arid regions.
Aromatic sulphonation. Part 76. Sulphonation in sulphuric acid of ω-phenylalkanes containing the NH3+, NMe3+, or NO2 substituent at position 1. Comparison of the side-chain NH3+, NMe3+, NO2, SO3H,…
The sulphonation of a series of ω-phenylalkanes containing at position 1 the NH3+, NMe3+, and NO2 substituent in concentrated sulphuric acid at 25 °C has been studied, and partial rate factors for…
Solutes in sulphuric acid—V