Abstract:

The wood anatomy of 43 collections, from East Asia, of 5 species within Sect. Illicium (Illiciaceae, Illicium Linn.) and 13 species, one subspecies of Sect. Cymbostemon (Spach.) A.C. Smith (Illiciaceae, Illicium Linn.) is investigated by light microscopy and scanning electron microscopy. The wood is diffused porous. Vessel elements are long, narrow, thinwalled, and angular; ends highly oblique; perforation plates are scalariform with many bars; vesselray pitting is scalariform. Rays are heterogeneous II, and uniseriate with procumbent cells. Axial parenchyma is sparse, diffuse arrangement. Most of species in Illiciaceae have above these ancestral features which support the family is one of the most primitively woody groups with vessels in extant dicotyledon. The comparison of the wood anatomic characters between Sect. Illicium and Cymbostemon shows marked quantitive differences. Furthermore, many features are shared in both Illiciaceae and Schisandraceae which suggests that the two families are closely related and it seem reasonable to set up Illiciales including Illiciaceae and Schisandraceae. At the same time, some differences in wood of the two families exist, which support the construction of Illiciaceae only including Illicium and also indicate Illiciaceae may be more primitive than Schisandraceae. Moreover, the vulnerability of Sect. Cymbostemon is found higher than that of Sect. Illicium, which theoretically shows that Sect. Cymbostemon distributed higher altitude and latitude, may suffer more intensity of drought and frost than Sect. Illicium, and the difference of vulnerability also support the division of Illicium into two sections in East Asia.

Key words: Illiciaceae, Schisandraceae, Illicium Sect. Illicium, Illicium Sect. Cymbostemon, wood anatomy, vulnerability, East Asia