Abstract:
This study is the first investiqation of the flower and fruit morphoqenesis of faurea speciosa and the first comparative study of f. speciosa and Macadamia inteqrifolia. Certain aspects of flower and fruit anatomy of M. inteqrifolia have been studied in other parts of the world but no investigation of the flower and fruit qrowth under South African conditions has been undertaken before. The morpholoqical and anatomical characteristics of faurea and Macadamia indicate that they are primitive qenera of the Proteaceae. Macadamia however exhibits more primitive characteristics than faurea. The close relationship between the two species is demonstrated by the common characteristics as reqards flower differentiation, structure of the stamen, style, embryo sac and embryo. The chromosome number of f. speciosa is n:12, like most other South African members of the Proteaceae, but in M. inteqrifolia n:14. The ovary of inteqrifolia contains two pendulous atropous ovules, whilst in f. speciosa there are occasionally two, but usually only a sinqle hemitropous ovule. In both species the embryo is a Panaea variation of the Asterad type. The uniteqmic seed coat of inteqrifolia is formed by the testa and chalaza, thus tendinq towards a pachychalazal seed. Inf. speciosa the biteqmic seed coat is papery. The fruit of M. inteqrifolia is a follicle whilst that of f. speciosa is an achene. fruit abscission in M. inteqrifolia occurs durinq the first nine weeks followinq full flowerinq. In inteqrifolia the period of flower bud differentiation, flowerinq, fruit qrowth, fruit abscission and ripeninq under South African conditions were divided up accordinq to a time scale. fruit development occurs over 31 weeks and the period is divided into three staqes. Durinq Staqe I, which lasts for two weeks, the zyqote remains in rest. Staqe II is the period of seed development and extends over 12 weeks. Staqe III is the fruit ripeninQ period and lasts for 17 weeks. Further research should be undertaken to study the effects of temperature, moisture and nutrition on flowerinq and fruit qrowth in an effort to improve yields and nut quality of M. inteqrifolia.
