During ontogeny of an anatropous ovule, intercalary growth of the funiculus causes the ovule to rotate 180°, shifting the micropyle toward the future hilum. Bouman (1984) reported that orthotropous ovules occur in about 20 families (e.g. Araceae, Cistaceae and Polygonaceae). The funiculus, chalaza, nucellus and micropyle are in an upright