Sentence Examples with the word polyhedral

In some cases leaves, as in Iris, or leaf-like petioles, as in Australian acacias and eucalypti, have their plane of expansion parallel to the axis of the shoot, there is then no distinction into an upper and a lower face, but the two sides are developed alike; or the leaf may have a cylindrical or polyhedral form, as in mesembryanthemum.

In Ulva and Mesocarpus the chromatophore is a single plate, which in the latter genus places its edge towards the incident light; in Spirogyra they are spiral bands embedded in the primordial utricle; in Zygnema they are a pair of stellate masses, the rays of which branch peripherally; in Oedogonium they are longitudinally-disposed anastomosing bands; in Desmids plates with irregular margins; in Cladophora polyhedral plates; in Vaucheria minute elliptical bodies occurring in immense numbers.