Showing papers on "Pedaliaceae published in 1988"
TL;DR: Dormancy and germination ecology of two Harpagophytum species (Pedaliaceae) from an open Acacia savanna in Botswana were investigated and dormancy is governed partly by the seed coat but mainly by the endosperm and the embryo itself, as demonstrated by removal of theEndosperm.
Abstract: Dormancy and germination ecology of two Harpagophytum species (Pedaliaceae) from an open Acacia savanna in Botswana were investigated. The maintenance of dormancy is governed partly by the seed coat but mainly by the endosperm and the embryo itself, as demonstrated by removal of the endosperm. Dissemination of the seed from the fruit can be delayed for several years without affecting the viability of the embryo, due to very low respiration rates.Germination can be enhanced slightly by high temperatures under natural conditions, and by gibberellic acid or removal of the endosperm under laboratory conditions. Relative growth rates for both Harpagophytum species are lower than for subtropical grasses and legumes, due to a strong investment in root and tuber biomass. Germination and seedling growth is discussed in relation to the drought avoidance syndrome and the animal disperser syndrome.
21 citations
TL;DR: Comparisons of pollen morphology suggested that the Martyniaceae and the Pedaliaceae should be maintained as separate families and Proboscidea and Ibicella should be kept as separate family.
Abstract: The pollen morphology as shown with scanning and transmission electron micros- copy of a sample of 10 species of the Martyniaceae revealed three distinct types within this family: reticulate (in Martynia), areolate (ProboscidealIbicella), and "ring-like" (Craniolaria). Pollen mor- phology coincided with other characters and suggested that Proboscidea and Ibicella should be con- sidered congeneric. Neither SEM nor TEM resolved the aperture type. Intergeneric differences in pollen morphology may be associated with differences in pollinators. Comparisons of pollen sug- gested that the Martyniaceae and the Pedaliaceae should be maintained as separate families.
16 citations