THE ANATOMY OF HAUSTORIA AND RELATED ORGANS OF GAIADENDRON (LORANTHACEAE)

Abstract

The internal organization of the radicle, tuber, secondary roots, and haustoria is described for Gaiadendron punctatum (Ruíz & Pavon) G. Don. The root is characterized by a distinct root cap, an endodermis, and a tetrarch vascular pattern which is to some degree perpetuated after secondary growth sets in. Root hairs are absent from radicle and secondary roots. Haustoria are of the santalaceous type although a "gland" has not yet been found. Anatomical features confirm a close relationship of the genus with Atkinsonia and Nuytsia and emphasize the primitive position of these three genera within Loranthaceae–Loranthoideae.