虎皮楠屬專論（I）

Monograph of Daphniphyllum (I)

The identification of species of Daphniphyllum has been extraordinarily difficult. Access to a wealth of herbarium material, including almost all type specimens, has made it possible to present a more complete classification of the genus. Based on a study of 2600 specimens, seven species have been retained as valid from a total of 65 specific names, and two new species have been proposed within three recognized sections of the genus. The conclusion is reached that speciation in Daphniphyllum is undergoing a reductional modification in floral morphology which I recognize in several intermediate stages representing members of the sections Lunata and Calycifera and a final stage consisting of taxa in the section Staminodia. The taxonomic position and affinity of Daphniphyllum have remained ambiguous. The genus has been placed in the Euphorbiales, Hamamelidales, Pittosporales, and in the monotypic order Daphniphyllales, but opinions have usually been based on fragmentary evidence. Following a comparative study of the gross morphology, wood anatomy, pollen morphology, chromosome complements, and chemical components of Daphniphyllum in relation to those families thought to be allied to the genus, viz., Buxaceae, Cercidiphyllaceae, Eucommiaceae, Euphorbiaceae, Hamamelidaceae, Pittosporaceae, Platanaceae, Stachyuraceae, and Trochodendraceae, I am able to confirm Hurusawa's proposal that Daphniphyllum be treated as an independent order, the Daphniphyllales, and also Hallier's proposal that the order be closely associated with the Hamamelidales.