Systematics Phylogeny And Reproductive Biology Of Mitrephora Annonaceae PDF Download

(Uncorrected OCR) Abstract of thesis entitled SYSTEMATICS, PHYLOGENY AND REPRODUCTIVE BIOLOGY OF Mitrephora (ANNONACEAE) submitted by Aruna Dharmapriya Weerasooriya for the degree of Doctor of Philosophy at the University of Hong Kong in August 2001 Mitrephora is a genus of shrubs and small to large trees widely distributed in tropical Asia, extending from China in the north, to India in the west and Australia in the south-east; the center of diversity lies in the Philippines and Borneo. Most of the species are highly localized and confined to specific habitats such as ultramafic formations, limestone forests and marshy forests, while a few species are widely distributed in dipterocarp forests. A complete taxonomic revision of the genus has been conducted for the first time. 48 species (including 15 new species) are described, although four of the species are not formally named due to lack of flowering material. Morphological and ultrastructural characters are discussed and their utility in species delimitation evaluated. Several anatomical features are described here for the first time. The presence of rhomboid crystals in the epidermal cells over the vein is consistent, and is an important diagnostic character for the genus. The inflorescences are basically terminal, although they subsequently appear as either leaf opposed or extra-axillary; only one species possesses solitary flowers, resulting from reduction of the inflorescence. The length of the flower pedicel, size of basal and median bracts, sepals, and inner and outer petals are variable among species. The petal indumentum generally consists of simple hairs; only one species possesses glandular hairs on the adaxial surface of inner petals. The density of hairs on petals is an important character in species delimitation. The structure of stamens and carpels are consistent within the genus, although their number and size are variable. The tetrad pollen grains and bi-seriate, laterally arranged ovules are cons.