The vascular anatomy of petioles and petiolules of ten species of Araliaceae represents all the leaf forms, from simple to compound were studied. The vascular anatomy of compound leaves petioles was shoot-like vascular elements. The characters obtained were analyzed by the NTSYS-pc program package, using the UPGMA clustering method. The produced dendrogram showed an independent separation of simple leaf (Meryta denhamii) from lobed and compound leaves. Lobed leaf species (Hedera helix and Tetrapanax papyrifer) are early separated from the compound leaf taxa. All the compound leaf taxa (Polyscias fruticosa, P. guilfoylei, P. scutellaria, Schefflera actinophylla, S. arboricola and Sciadophyllum pulchrum) were clustered together. The lobed leaf could be considered as a type of compound forms. Compound leaves seem to have an independent origin from an ancestrally simple state.
Key words: Araliaceae, petiolar anatomy, simple leaf, lobed and compound leaves
|