Stauros

A stauros is a hyaline thickening of silica in the central area of a valve, found only in the genus Stauroneis.

Some references consider a fascia and a stauros to be equivalent structures, but recent work (Cox 1999, 2001, 2012) has shown that the stauros has a distinct pattern of development. During valve formation in Stauroneis, a transverse strip of silica develops from each side of the central nodule.

Citations

Cox, E.J. (1999) Craspedostauros gen. nov., a new diatom genus for some unusual marine raphid diatoms previously placed in Stauroneis Ehrenberg and Stauronella Mereschkowsky (Bacillariophyta) European Journal of Phycology 34: 131–47
Cox, E.J. (2001) What constitutes a stauros? A morphogenetic perspective In Jahn, R., Witkowski, A. & Compe`re, P. [Eds.] Festschrift füe H. Lange-Bertalot. A.R.G. Gantner Verlag K.G, Ruggell, Liechtenstein, pp. 303–16
Cox, E.J. (2012) Ontogeny, homology, and terminology - wall morphogenesis as an aid to character recognition and character state definition for pennate diatom systematics Journal of Phycology 48: 1–31

Publication Link: 10.1111/j.1529-8817.2011.01081.x

Cruciform — Light micrograph of a *Stauroneis* species. Indicated by the arrow, the stauros is the hyaline area extending from the central nodule to the valve margins. It is characteristic of *Stauroneis*.