WOOD ANATOMY OF TREES AND SHRUBS FROM CHINA .3. ROSACEAE

The wood anatomy of 162 species from China, belonging to 30 genera of the Rosaceae is described. The structural diversity is documented in a survey of characters, a family description, generic descriptions and tables. A key to the genera or groups of genera is presented. A number of genera is described wood anatomically for the first time. Vestured pits noted in some Spiraea species are newly recorded for the family. The phenomenon of fibre dimorphism in Spiraea is analysed in detail. The systematic implications of the wood anatomical diversity summarised in Tables 22-24 are discussed at and below the subfamily level. The Spiraeoideae and Rosoideae resemble each other very closely, but Exochorda, and to a lesser extent Sorbaria, are aberrant within this group. Exochorda resembles the Prunoideae in its wood anatomy. The Maloideae constitute a very homogeneous alliance, of which individual genera cannot be separated, but two groups can be recognised, only differing in degree of ray heterogeneity. The Prunoideae are wood anatomically the most heterogeneous and eight groups in Chinese Prunoideae can be recognised: Prinsepia and seven groups within the Prunus alliance (Table 24).