Arabesques, or floral and vegetal motifs, derive from a long tradition of similar motifs in Syrian, Hellenistic, and Roman architectural ornamentation. Early arabesque motifs in Umayyad Cordoba, such as those seen at the Great Mosque or Madinat al-Zahra, continued to make use of acanthus leaves and grapevine motifs from this Hellenistic tradition. Almoravid and Almohad architecture made more use of a general striated leaf motif, often curling and splitting into unequal parts along an axis of symmetry. Palmettes and, to a lesser extent, seashell and pine cone images were also featured. In the late 16th century, Saadian architecture sometimes made use of a mandorla-type (or almond-shaped) motif which may have been of Ottoman influence. "Interlacing" motifs (sebka and darj wa ktaf) Various types of interlacing lozenge-like motifs are heavily featured on the surface of minarets starting in the Almohad period (12th-13th centuries) and are later found in other decoration such as carved stucco along walls in Marinid (and Nasrid) architecture, eventually becoming a standard feature in the Moroccan ornamental repertoire in combination with arabesques. This motif, typically called sebka (meaning "net"), is believed by some scholars to have originated with the large interlacing arches in the 10th-century extension of the Great Mosque of Cordoba by Caliph al-Hakam II. It was then miniaturized and widened into a repeating net-like pattern that can cover surfaces. This motif, in turn, had many detailed variations. One common version, called darj wa ktaf ("step and shoulder") by Moroccan craftsmen, makes use of alternating straight and curved lines which cross each other on their symmetrical axes, forming a motif that looks roughly like a fleur-de-lys or palmette shape. Another version, also commonly found on minarets in alternation with the darj wa ktaf, consists of interlacing multifoil/polylobed arches which form a repeating partial trefoil shape. Geometric patterns Geometric patterns, most typically making use of intersecting straight lines which are rotated to form a radiating star-like pattern, were common in Islamic architecture generally and across Moroccan architecture. These are found in carved stucco and wood decoration, and most notably in zellij mosaic tilework. Other polygon motifs are also found, often in combination with arabesques. Epigraphy and Arabic calligraphy Many Islamic monuments feature inscriptions of one kind or another which serve to either decorate or inform, or both. Arabic calligraphy, as in other parts of the Muslim world, was also an art form. Many buildings had foundation inscriptions which