has recently extended the analysis to cover Chinese art, which Riegl did not cover, tracing many elements of Chinese decoration back to the same tradition, the shared background helping make the assimilation of Chinese motifs into Persian art after the Mongol invasion harmonious and productive. Many arabesque patterns disappear at (or "under", as it often appears to a viewer) a framing edge without ending and thus can be regarded as infinitely extendable outside the space they actually occupy; this was certainly a distinctive feature of the Islamic form, though not without precedent. Most but not all foliage decoration in the preceding cultures terminated at the edge of the occupied space, although infinitely repeatable patterns in foliage are very common in the modern world in wallpaper and textiles. Typically, in earlier forms there is no attempt at realism; no particular species of plant is being imitated, and the forms are often botanically impossible or implausible. "Leaf" forms typically spring sideways from the stem, in what is often called a "half-palmette" form, named after its distant and very different looking ancestor in ancient Egyptian and Greek ornament. New stems spring from leaf-tips, a type often called honeysuckle, and the stems often have no tips, winding endlessly out of the space. The early Mshatta Facade is recognisably some sort of vine, with conventional leaves on the end of short stalks and bunches of grapes or berries, but later forms usually lack these. Flowers are rare until about 1500, after which they appear more often, especially in Ottoman art, and are often identifiable by species. In Ottoman art the large and feathery leaves called saz became very popular, and were elaborated in drawings showing just one or more large leaves. Eventually floral decoration mostly derived from Chinese styles, especially those of Chinese porcelain, replaces the arabesque in many types of work, such as pottery, textiles and miniatures. Significance in Islam The arabesques and geometric patterns of Islamic art are often said to arise from the Islamic view of the world (see above). The depiction of animals and people is generally discouraged, which explains the preference for abstract geometric patterns. There are two modes to arabesque art. The first mode recalls the principles that govern the order of the world. These principles include the bare basics of what makes objects structurally sound and, by extension, beautiful (i.e. the angle and the fixed/static shapes that it