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adj. Botany
Growing straight, so that the micropyle is at the end opposite the stalk. Used of an ovule.


(Botany) (of a plant ovule) growing straight during development so that the micropyle is at the apex. Compare anatropous


(ɔrˈθɒ trə pəs)

(of an ovule) straight and symmetrical, with the chalaza at the evident base and the micropyle at the opposite extremity.
[1820–30; < New Latin orthotropus]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.orthotropous - (of a plant ovule) completely straight with the micropyle at the apex
plant life, flora, plant - (botany) a living organism lacking the power of locomotion
campylotropous - (of a plant ovule) curved with the micropyle near the base almost touching its stalk
References in periodicals archive ?
Gymnosperm ovules are always unitegmic and also orthotropous so that the podocarp ovule may be seen as anticipating the anatropous ovule of flowering plants, the second integument being responsible for the necessary asymmetric growth.
Xyridoideae (Xyris) were circumscribed with unifacial leaves; ellipsoid, sulcate pollen; orthotropous ovules; and ellipsoid seeds (Dahlgren et al.