Wood Anatomy and Familial Status of Viviania

Wood of three species of Viviania from Chile was studied. The wood has growth rings, moderately grouped vessels, helical sculpture in vessels, fiber-tracheids with small pits, and various degrees of storying. Axial parenchyma and rays are absent, regardless of age of stem. These facts are in accord with close relationship to other genera of Geraniaceae s.l. Viviania differs from other Geraniaceae in presence of borders on imperforate tracheary elements and presence of endosperm; other differences (polyporate pollen; loculicidal capsules) are shared with some other genera which have familial status according to some authors, subfamilial status according to others. Viviania is probably the most distinctive element within Geraniaceae s.l., but other genera are close behind in this regard. Wood features of Viviania are in accord with the dry habitats occupied by this genus.